WEATHER MADE CLEAR FOR ALL TO HEAR

"But seeing they could not See; hearing they could not Hear"
“The views expressed herein are those of the author and do not necessarily represent those of the National Weather Service or affiliate/related organizations. Please consult .gov sites for official information”

"From its chamber comes the whirlwind, and cold from the scattering winds." - Job 37:9.

"The wind blows to the south and turns to the north; round and round it goes, ever returning on its course".

Monday, February 28, 2011

"Black Monday" Severe Weather Reports Filter In, Florida Warm and Breezy

Image: Above is the current depiction of severe weather related storm reports, some preliminary, as of noon Eastern Time on this "Black Monday", February 28th since yesterday. So far there has been 219 total reports of which 153 are wind related, 61 hail related, and 5 tornado related. Not visible underneath the blanket of reports is a few funnel cloud reports. *Note the Tornado Icon near northern Oklahoma (not placed exactly correctly in this image).  Also shown is the official risk areas today in the shaded area through 7AM EST Tuesday morning. The shading in Central Florida is for a risk of general thunder, with higher risk along I-10. Not shown in the image above is flooding related activity.

*Here  is an image from yesterday while activity was just getting underway in the Southern Plains. It shows the risk areas at that time from General to Moderate (in red). Over Kansas we can see (upon enlargement) a storm showing on radar. The little icons of vehicles are storm pursuers who have GPS/software enabled programs running through on-board laptop computers and have them in the "on" (detectable) position. Note how they are clustered near the storm that eventually produced a tornado as indicated in the first image. We can even see the identify of these folks via the inset to the right.


CENTRAL FLORIDA WEATHER TODAY: Breezy and warm. S-SSW winds 15-22 mph, gusts to 28 mph. The cold front is moving through the Deep South as I write. Several Tornado Watch boxes are in place at this time, and during the day these will be dropped with others being issued further to the east (or Severe Thunderstorm Watches) as the front progresses toward the coast. In fact, I'm hearing about tornado warnings in Tennessee at this very moment. So what the heck, here's what radar looks like in Tennessee at the time of these warnings. Note also the storms forming in Southwest Alabama. One of those could go severe (in my opinion).






But in Florida it will be very warm with highs in the low-mid 80s, much like yesterday.  Might be a few spotty upper 80s as well anywhere in the interior. Temperatures right near the coast might only make it to the 79-81F level along either coast. Expect a near side shore component to the wind along the East Coast today, more to onshore south of Ft. Pierce and around Canaveral Bight south toward Indian Harbor Beach. No rain under widely scattered clouds, becoming nearly clear some locations at times.


TONIGHT: The tail end of the rapidly weakening southern end of the storm system will move through Northwest Florida as the main parent low passes by Maine. Some heavy snow is expected up there with totals up to or maybe over 8" with very breezy winds to boot.   You can see the location of where the main low will be by 1pm EST in the image below near Maine. Winds over night will be lighter from the SW-WSW with lows mainly in the low-mid 60s with upper 60s along the coast and some low 70s SE Florida coast.


TUESDAY: Front will enter North Central Florida at day break and pass through that region between the hours of 7AM-1PM. Accompanying the boundary will be some light rain showers and a wind shift to the northwest.
By 1pm the boundary will roughly be located as shown here, or in other words, it will be entering South Central Florida.  At about this point the front will have nearly completely decoupled from any remaining upper level support (if not entirely) and frontolysis will be underway, but there will be ample moisture for the continued chance of rain showers over East Central Florida mainly from 10AM further  through 2pm as one goes south. Do not expect any thunderstorms anywhere south of St. Augustine (although the first graphic showed that will be the case).  The Storm Prediction Center has all of South Central and SE Florida in a chance of thunderstorms tomorrow, however believe that was mainly predicated upon the assumption there would be a sea breeze collision boundary against the predominant SW winds, however it is very unlikely a sea breeze will ever manifest, this no collision and no thunderstorms. Given there would be no other driving factors to contribute to thunderstorms other than weak thermal instability, I'm dropping them from the 'unofficial' post. If there's to be any thunder tomorrow believe it would be near West Palm later in the afternoon.  

As we see in the included image, I've drawn the front in as 'breaking up' with a weak stationary boundary generated, in part, off a thermally induced surface low within the warm waters of the Loop Current in the Gulf.   A portion of this low could simply relocate during/after peak heating to just off the coast of Ft. Lauderdale late in the date as high pressure builds south. 


By Wednesday afternoon whatever remain of either boundary will be just south of the Keys.  Rain showers will be possible as well further south along the east side of the state and over the Keys.


Once all is said and done with this portion of today's forecast post (through tomorrow night), rainfall totals will range from a Trace to perhaps 0.25" (quarter of an inch). Believe any 'true' thunder to occur would be just offshore the east coast of Boyton Beach to Miami. There is a sparse chance of a renegade rain shower from the Cape and South through midnight, Tuesday night though as a tongue of upper level energy will ride over Central Florida possibly re-manifesting a shower at some point.


WEDNESDAY: Winds will shift from NW to ENE by Wednesday morning just about everywhere except extreme South Florida will the boundary will have yet to clear.  Temperatures on Wednesday will be in the mid 70s to near 80F on the west side of the state under partly cloudy skies, possibly mostly cloudy SE Florida where low end rain chances remain, perhaps a better chance SW Florida.


THURSDAY-SATURDAY: Brisk East Winds becoming ESE-SE by Saturday and picking up gradually through the time frame. Highs in the mid-upper 70s and lows in the mid-upper 60s, cooler far inland and west Florida.


NEXT BEST CHANCE OF RAIN: Perhaps Saturday, but more likely Sunday sometime. Thunder might be included in this time frame as well.  But per the long range run of the GFS model, the next couple of fronts to impact Florida will do so in similar fashion as the one tomorrow will, with the state getting only the remnant sloppy seconds (at best) of anything of "dynamic" nature. But still watching the weekend time frame  closely from something "...more than".

No comments:

Sunday, February 27, 2011

"Black Monday" Begins Later Today - Sunshine State Lives Up To Name

Image: Surface plot for 7AM (EST) Monday morning, shows the general placement of surface features at the time. By this time, a tri-modal "Black Monday" (see below) severe weather will be occurring.  The yellow area shows a generalized area of most intense activity/areal coverage with the aqua showing other severe type activity to occur through Monday, spreading east with time.  Not shown is additional flash flooding concerns in South East Ohio, parts of Kentucky, Indiana, and Pennsylvania (to name a few).

TODAY: High pressure will reign supreme today as the last of yesterday's surface features which layed dormant overnight are quickly eroding during the first hours of daylight. All upper level support for any feature other than the high pressure ridge axis shown in this image exited during the wee hours.


This afternoon will be warm and sunny. Coolest temperatures in the upper 70s will be found primarily within 1 mile of any coast due to light afternoon sea breezes, quickly warming as one heads toward the interior into the low-mid 80s. Warmest temperatures by mid-afternoon will be located in general within the bounds of the yellow area I've sketched in. Coastal temperatures south of North Central and Northwest Florida will not be as greatly effected as they were earlier this month  (in the cool sense) due to warming sea surface temperatures the past 10 days. For example, the temperature at the Cocoa Beach pier has warmed from the lower 60s to 70F. The temperatures off Daytona have warmed into the low to mid-60s from the mid-upper 50s as well. Last to warm will likely be those offshore the coast of St. Augustine to JAX and perhaps along the Panhandle Coast.  Inland lakes, including Okeechobee have also warmed notably since those of  early and mid-month readings.


Winds today over the South half of the state will be primarily from the SE once the diurnal heating/temperature cycle is fully in place. No rain today with less clouds, some locations may barely see a cloud at all.


TONIGHT/MONDAY: Winds become near calm overnight, with a few patches of shallow inland fog. Lows in the low-mid 60s many locations, with a few upper 50s well inland north of Lake Okeechobee and North Florida.  Afternoon temperatures will be warmer all locations on the east side of the state than today, reaching into the low 80Fs. Winds will be generally from the South at 10-18mph during the afternoon, but gain a bit of a more onshore component during the afternoon which could take coastal temperatures back down to the upper 70s with a few more cumulus expected inland as high pressure relaxes a bit to the east and south preceding the approach of the approaching storm system 'complex' towards the U.S. Coast, primarily from Eastern Georgia to New York.


Meanwhile, a  complex Tri-Modal  synoptic scale configuration of a variety of atmospheric conditions consisting of at least two or three low pressure systems, a warm front, cold front, and dry line (initially)  will create areas of combined directional/speed shearing wind profiles and thermal/moisture gradients, just to name a few to generate storm modes ranging from flat out long duration heavy rains to a QLCS type squall line (primarily the south portion originally) to more isolated, discrete rotating thunderstorm structures which will  spread east with time. The QLCS is essentially a 'mixed mode' line of embedded discrete cells with bowing line segments, rather than a flat out linear squall line. Backbuilding storm cells (that is to say, regeneration of newer storm activity following intial storms) after the first severe weather threat has passed, could re-initiate in the area just along and south of where the warm front is located particularily over NE Arksansas, West Tennesse, SW Kentucky, and Southern Illinois. 


There is a moderate risk of severe weather associated with this said scenario as discussed by the Storm Prediction Center (SPC) embedded within a very large area of slight risk which will expand with time toward the U.S. East Coast.  Florida is not included in any of this activity though, at least not in the 'severe' weather sense at any time. Strong tornadoes are possible, most specifically from South Central Arkansas  northeastward to Western Tennessee and extreme SW Kentucky, not to discount other areas where this region will be potentially impacted first by discrete cells and then, after a lull in activity, by the quasi-linear convective system. Other outside areas to watch will be SE Kansas toward Southern Oklahoma (east of I-35).


 And we've only discussed the forecast synoptic scale features. Within those features will be the mesoscale boundaries/nuances that will evolve/activate beyond the scope of any forecast other than  short short or real-time releases.


Local weather offices and media services are all handling their area of interest and will be issuing the proper watches/warnings/alerts as the activity unfolds.  This severe weather event will likely be much more significant than the event which occurred  just a few days ago as was expected would be the case in the post written a few days ago.  Recall, there was over 200 severe weather reports with the last system. Believe this go around we might be able to double that number, namely in the wind damage report category.  Outside of the risk of tornadoes (some could be strong, long tracking) and winds, flash flooding will be a big concern in those areas that already have estuaries nearly full from last week.  The only  fatalities from last weeks severe weather event were caused  indirectly by drowning (Arkansas).


TUESDAY: Last of "Black Monday" will be offshore or nearly so in regards to severe thunderstorms by afternoon, although the areas of flood potential will remain in part of the Ohio Valley and South half of Pennsyslvania.  The cold front  will extend across North Central Florida and will cross Central proper between 11am - 2pm.  During/after this time the surface features will start to decouple from the upper level support.  By sunset the front should be as far south as somewhere between Vero Beach-Ft Pierce on the east side.  After dark through sunrise Wednesday the remnants will sneak through South Florida to be located along or even south of the Florida Straits by mid-afternoon.


Best chance of rain with the front will over North Central Florida and eastern portions of South Central from 10AM - sunset, working south with time.  Still giving us a 30/40% chance of rain during this time as was posted two days ago, but some places already have a 100% chance of rain (at any one given location), we just don't know exactly where those location will be.  


Hedging at looking at all of South half Volusia, Brevard, Seminole, Indian River, and St. Lucie County continuing south to the north half of Palm Beach county when all is said and done overnight Tuesday night.  Only difference in thinking is to take out thunder chances altogether, although will leave in a 10% chance of a rumble from 11AM - 3PM from Sanford south to Sebastian and inland toward eastern Orange County and Osceola County.  Only because of the timing of the boundary passing during peak heating.  But even that appears is a stretch (for thunder) given there will be close to nil instability due to lack of insolation (preceding cloud cover) and weak wind profiles as the system decouples.


WEDNESDAY-FRIDAY: Winds will be NE-ENE almost immediately following frontal passage. Long term ENE-ESE winds will follow during this time frame, with a long fetch off the Atlantic. Prolonged onshore flow could generate coastal showers first over SE Florida then working to Central and North Central Coasts on Thursday/Friday. High in the 70s, lows in the 60s and a rip current threat for the entire East Florida coastline.


BEYOND: Next system will approach 'sometime' next weekend or beyond. There is large disagreement with model guidance regarding the next storm system. The trend of the GFS has been showing a much more dynamic system though (at least in the past 24 hours worth of model runs), so it bears watching.

No comments:

Saturday, February 26, 2011

Very Pleasant and Warm South Central and South


TODAYAs we you see, we are dealing somewhat with two boundaries this Saturday morning. The first image shows where 'technically in one sense" what remains of the cold front that impact much of the Eastern portions of the country lies across North Florida. However, on the southern fringes of the strongest mid and upper level winds aloft there lies a moisture gradient (along with a few others) defining a secondary stationary boundary across dead Central Florida at 9AM this morning.  Any weather to occur over Florida of cloud or light shower nature will be along and north of this boundary (and south of the more northern one).

s we can see, we are dealing somewhat with two boundaries this Saturday morning. The first image shows where 'technically in one sense" what remains of the cold front that impact much of the Eastern portions of the country lies across North Florida. However, on the southern fringes of the strongest mid and upper level winds aloft there lies a moisture gradient (along with a few others) defining a secondary stationary boundary across dead Central Florida at 9AM this morning.  Any weather to occur over Florida of cloud or light shower nature will be along and north of this boundary (and south of the more northern one).



In this image we see where Suface Moisture Flux Divergence (Low level Moisture Convergence) is occurring along the 'weather making' boundary. Very little will change with this configuration today

This image shows that the greatest overall atmospheric moisture through the mid-level reside north of the stationary boundary. Satellite imagery implies there is more than what is shown here. Steering is from west to east of the clouds.

Finally. I'll include the morning visible satellite imagery to show that indeed the greatest amount of cloud coverage is along and north of the boundary where the greatest moisture resides.


I've also drawn in where I believe the warmest temperatures will be today PREDOMINATELY. The large reddish circled area is the 80Fs, with the purple area being mid-80s.  Under the clouds today temperatures will probably struggle to break 80F.  Not shown, is the area north of the cool front in clearing skies. Some spots here might also get close to 80F as well, just to show how weak the overall thermally speaking, actually is.  The coolest areas will be along the coasts within the bounds of the light blue lines.

Also shown in the image above is where the best chance of a sprinkle will exist. Perhaps the best chance of all though by day's end will be that area on the east side of the state.

TO RECAP: Partly cloudy south and south central today south of the stationary front and warm with highs in the low-mid 80s. Along and north of the boundary highs in the upper 70s, and perhaps mid-70s in the coolest areas.  The area along East Central might not receive a sea breeze until after 1 or 2pm, and could warm to 80F before onset of the sea breeze, contingent upon the amount of cloud cover, especially the area in Brevard. But have a feeling clouds will move in shortly to offset that magic mark.

Otherwise, very pleasant with light winds this afternoon, coolest within 1/2 mile of the coasts. Warmest interior South. Slight chance of a light shower as shown above, with the best chance (15%) near SR50 from Sanford to Titusville and into SW Volusia County.

TONIGHT/SUNDAY: Boundary will remain in place until daytime heating tomorrow, or roughly 11AM-1PM.  Winds tomorrow will become ESE-SE by later in the day as the uplift provided by the stronger winds aloft pulls away no longer provided a source of lift in the mid-levels for that cloud deck shown in the satellite image.  For could again be an issue tonight after mid-night through early Sunday where the clouds are no longer an issue. Temperatures on Sunday similar to today, but probably a bit warmer than today where the clouds will have remained most prevalent.  

Otherwise, storm system in the South Central Plains takes shape and begins to impact the east 1/2 of Oklahoma eastward into Southern Missouri, all of Arkansas, and Northern Louisiana, and NW Mississippi. This system's greatest severe weather impacts (in regards to the potential for tornadogenesis) will be near dark Sunday night and overnight into mid-morning Monday as the system en-masse moves east and a bit northward with time toward the Mid-Atlantic and NE states.

MONDAY: Yet another nice day as breezes pick up a notch from the SE-SSE during the afternoon under partly cloudy skies.  The Plains system will have cleared Oklahoma by daybreak, and will impact all of Arkansas in some form or another, eastern Missouri, and Southern Illinois...as well as the west half of Tennessee. There is a very fine corridor of greatest tornado potential during the course of events within a very broad area that the Storm Prediction Center has placed in a "Slight Risk" for severe weather. Believe the initial area will be near Ardmore, Oklahoma (extreme South Central OK) before sunset, but there are a few other locations such as west of Wichita, Kansas as well as NW Missouri to name just a few other 'outliers'. Looks likely that this will primarily be a QLCS event (much like the one the other day)...along the southern extent of the storm complex. Further north such as near N. Missouri, much of Arkansas, and into S. Illinois there will be a great chance for discrete storm cells embedded within otherwise cloudy sky conditions where the greatest helicity (spin potential) will be.  The greatest low level forcing will be further south in the liner mode region, however this area may very well be highly-capped under CIN

TUESDAY: The attendant cold front from the system described above will be across NW Florida and entering North Central Portions at daybreak.  Winds overnight Monday into Tuesday will pick up from the SW over Central Florida particularly overnight. Another muggy, warm for this time of year evening in store with little concerns for fog except maybe over South Florida (interior).  Lows in the mid-60s...maybe even some upper 60s East Central.

The front will reach roughly from Titusville to Tampa around 2-4pm, accompanied by clouds most definitely and showers (still give it a 30/40% chance of rain coverage in beginning late morning through mid-afternoon). I'll give thunder chances a 15% chances namely over East Central Florida from Orlando -Sanford-Oakhill and down the coast to just south of Vero Beach (later in the day) and into the NE Quadrant of Osceola County, and throw in the east side of Orlando for good measure.

TUESDAY NIGHT/WEDNESDAY: From will reach the Miami Metro. Winds central swing around to ENE, but light. Partly cloudy with shower chances from West Palm and South, especially after late morning. But chances of thunder of South Florida appear will be over the interior and SW portion. Very small chances at that.  Still appears the boundary will make it to the Florida Straits by Wednesday night before completely washing out to the east. However, this will be just the beginning of an entirely new weather scenario through the end of the work week.

Only change to yesterday's line of thinking is that perhaps the strongest easterly winds to develop from the Cape to Miami might remain offshore, with the best chances of showers to be along the Treasure Coast to Miami Thursday and Friday. Temperatures will run about normal for afternoon highs, with warmer than normal overnight lows (low-mid 60s A1A, mid-upper 50s interior).


No comments:

Friday, February 25, 2011

Warm Statewide Today, Breezy Early


Image: Visible satellite image captured after launch of Discovery yesterday shows in the circled area the contrail visible from space. With close inspection one can see the contrail plume in the center of the circle.

RECAP: Storm system that gained much hype in the weather world prior to yesterday continues east toward the Mid-NE Atlantic coast this morning as I type, in a much weakened state. So far there's been 10 tornado reports all in all, but none of them appears to have been a major headline maker. But there was some significant damage reports filtering in. Other than one, all the reports came in from Arkansas and Tennessee, where in Weakley it was reported that tombstones were pulled out of the ground and in Davidson two churches were damaged. "Holy Moses!". There are some reports of rather significant damage but none of 'total destruction'. There was also 202 wind damage reports and 4 of severe category sized hail.

TODAY: The related surface cold front will continue into N. Florida today. Preceding the front clockwise cirulation around high pressure to the east and south of Florida will generate a brisk SW wind late morning through early afternoon, with gusts to 25-28mph possible, but they will weaken by 2-3pm. Some clearing early should give way to a generous portion of afternoon cumulus type clouds this afternoon with the high in East Central Florida perhaps breaking a previous record (at MLB at least). Today's record their is only 84F, and it appears that is easily within reach considering I expect to see widespread low-mid 80s with a few spots in the upper 80s South Central and South. Winds she relax by mid to late afternoon. The only spot that might get a sea breeze will be south of West Palm very late afternoon and only very close to the coast.

TONIGHT: Boundary sinks to near a Daytona Beach to Brooksville line as winds go near calm overnight and becomes stationary while losing all frontal feature integrity. Good bet for some fog tonight over a broad expanse through mid-morning Saturday.

SATURDAY: Other than a scant chance of a spit of rain, and perhaps drizzle under the boundary overnight and early morning, winds will be light with light sea breezes right along both coasts in the afternoon under partly cloudy skies once the clouds/fog break (assuming they materialize). All rain chances gone statewide with another warm day in store (note quite as warm Central), especially over South Florida away from the immediate coast.

SUNDAY: Another foggy start quite possible with light afternoon sea breezes and temperatures running a few degrees above normal, but really nothing different than what we've felt in recent days past. Winds becoming more southeasterly during the course of the afternoon.

MONDAY: Next front will be approaching, SW winds once again accompanied by warmer temperatures across the boards. No rain.

TUESDAY: Front will move through NW Florida overnight and enter North Central Portion at day break with a chance of showers followed by a NW wind shift behind the boundary (quickly becoming NE within 3-6 hours after that point). Front will sink toward South Central Florida by sunset. Best chance of rain (I'll give it a 30/40% chance) will be across East Central Proper from sometime between 11am - 7pm, from north to south with time. Furthest southern extent of these rain chances will be between Ft. Pierce and West Palm by early evening. Could hear a rumble of thunder from Titusvillel south to Ft. Pierce after 1pm on the east side of the state along the front as it passes through. Not expecting thunder at this point far SE Florida.

WEDNESDAY BEYOND: Pattern change in store as front resides along the Florida Straits just south of the Keys and north of Cuba. No big cold surges just as a hint, but could be hearing about coastal small craft advisories/hazardous rip currents by late Tuesday -Friday due to prolonged onshore flow, breezy at times, as well as coastal showers. I stress "Could"...but the pattern seems to be set for a good 3 days of easterlies combined with a shallow but moist onshore flow evolving within this time frame before the next front arrives by late weekend. Might not be so sunny either, perhaps mostly cloudy. No thunderstorms.

No comments:

Thursday, February 24, 2011

Will STS-133 Shuttle Discovery Be Able To Launch Today?



Images: (1) KSC mesonet with launch area circled in lime color. (2) State wide Local Data Integration shows a very weak low pressure circulation just off Canaveral Blight in the lee of of the Gulf Stream where upstream east to eventually SSEasterlies will develop late this afternoon. A few light rain showers are well offshore, and gray/silver lining shows the greatest cloud coverage at this time.

NOW: Morning fog many areas state wide is burning off and skies are completely clear at Canaveral with a light east wind. Subsidence aloft and in the windward side of cool, light onshore flow is scouring out the clouds at KSC, but dew points remain high, at least until early afternoon. The current conditions might be a bit misleading considering that a transition, albeit insignificant outside of a rocket launch concern, is underway. In the image above, we see what has become this season a very weak cyclonic circulation just east of Canaveral Bight formed by weak overnight land breezes , the remaining old frontal boundary, and stronger SE flow trying to develop...all along an inverted coastal trough tracing the west side of the warmer Gulf Stream waters.

TODAY: As high pressure off the coast of South Carolina strengthens a bit and drops south and east a bit in response to today's severe weather maker for parts of "Dixie Alley" (especially from East Central Arkansas to Western Tennessee, NW Mississippi, extreme NE Louisiana, and SW Kenucky) which will be pressing east throughout the afternoon and into the eveing, the coastal trough will wash out as it forced to cross the cooler near shore waters from where it currently resides and toward the Florida East Coast. Light easterlies this afternoon will transition to SSE around launch time blowing around 12-18mph (perhaps gusts to 22mph). As such, do not believe winds will be a factor.

Otherwise, during the transition a light, short lived rain shower could approach the coast, but the likelihood of one to manifest off the cool ocean waters (or survive the journey away from the warm, moisture Gulf stream waters source) seems very low. However, cloudiness of ' partly cloudy' nature is a possibility. Even so, do not think 'triggered lightning' will be a concern today due to very low end convective nature of the cloud types.

Only concern today from the meteorological perspective is whether or not a broken deck will manifest at around 4500 ft. later this afternoon after peak heating. Like mentioned, at this time it's clear as a bell out there, and that may very well end up being the case right up until launch time. But I wouldn't lay 1000 dollars on it. I'd give it a 65% chance of a go, at least right at launch time. If we don't start seeing clouds appear between 3-4pm we probably never well.

Best chance of clouds appearing will be between 4:30pm through 7pm....somewhere within that time frame as the boundary will become absorbed in the averaged SSE flow and spreads any coverged moisture onshore, lasting because a SSE wind blows across warmer ocean waters than one from any northerly component are at this time of year. By the time we reach the waning minutes of daylight clouds should disperse, with significant clearing within 1 hour after dark.

BEYOND TODAY: SSE winds all night will gradually veer to SSW by sunrise Friday. It will even be a little breezy right after sunrise tomorrow, and warm all along the East Coast, especially north Vero Beach. Highs in the mid-80s, and a few spots of upper 80Fs. Melbourne's record high temperature for the date might again be jeopardized for the 3rd time this month, but probably won't be broken since I think the record high for the date is something like 90F (at least). Not sure, but the record high for today is 92F. Can tell we are in early spring now, with record highs in the 90F degree range and record lows on some days still down in the upper 20Fs.

SATURDAY: Dixie Alley Storm system Number 1 will trail into North Central Florida and meander as the boundary (cold front) fizzles. Tiny 15% chance of a shower over North Central/ North Florida. Not quite as warm as Friday as SW winds will have weakened considerably on Saturday, with coastal sea-breezes (light). Continued abnormally warm over South Florida with highs in mid-80s, closer to 80-82F Central with A1A coming in between 75F-79F. All in all though, still above average.

SUNDAY: Boundary still around, morning fog likely. Temperatures about the same as Saturday. Shower chance diminishes North Central and North. Warmer Monday (like Friday).

FIRST CHANCE OF SHOWERS? Overnight Monday into Tuesday morning North Central, shifting toward South Central and Southeast Florida Tuesday afternoon as Dixie Alley Storm System #2 will be moving in, and likely through, most of Florida...it gets sticky toward the Miami Metro Area. But we could see more coastal shower chances at various time going into late week and next weekend with temperatures close to normal rather than above average.

No comments:

Wednesday, February 23, 2011

"Where's Waldo?"


Image: Latest surface analysis of temperature, dewpoint, and pressure. I've drawn in solid blue a rough guestimate of where a frontal boundary is present (more or less), in yellow is where it will end up by day's end before washing out entirely overnight tonight. Not shown in the image above is a weak surface low well east of Central Florida.

TODAY: A little cooler today than yesterday over North Central and North Florida, most notably along the coast from Sebastian Inlet and north, more so north of the Pineda Causeway along A1A, with the coolest air North of Daytona Beach (along A1A).

"Backdoor-ish"...(perhaps "back-boorish") boundary is sliding south to southwest ward through NE Florida as I write. It has taken since just past midnight to get to the location shown above from the Georgia border, and little further southward progress will be made through the remainder of the day. Expect that it's last and final frontier (most southern extent) will be along the coast east of I-95 late afternoon to somewhere near the Pineda Causeway in Central Brevard Causeway. The northerly winds we have early today are a bit misleading (as was the cloudy/foggy conditions earlier combined with them), leading one to believe a front had gone through already.

The winds were actually a realignment of high pressure south and west of the state. Behind the boundary winds shift from NNW-N-NNE-NE. Believe those winds (that are associated with the boundary proper) will work into the False Cape area and through the Canaveral Bight area and into the Port of Canaveral by late afternoon, penetrating as far west as I-95...making southward motion on seemingly pure momentum as the front will already be aligned with the upper level westerlies and thickness values that are going nowhere further south beyond 7pm, perhaps abetted southward a bit by circulation around the weak surface low off the coast moving further south.

Very pleasant away from the East Coast everywhere Central and North with highs in the mid 70s to near 80F (if that's what you like). Coolest spot today all in all will be East of US1 north of Ormond Beach...cool air trying to wedge in from the NNE or near parallel to the coast could impact A1A residents as far south as Patrick AFB late this afternoon. Either way, highs there will be in the low 70s except north of Ormond Beach where highs might never get out of the mid-upper 60s ([perhaps low 60Fs at coastal JAX). Warmest South Central and South Florida with highs in the low 80s. Don't think they'll eke out predominant mid-80Fs down there again today (like yesterday) with the Northerly wind.

TONIGHT-THURSDAY: Winds will let up significantly from the 10-18mph of this afternoon tonight and attain a more ENE to due East direction late night to early morning...perhaps near calm (especially inland) tonight. Fog many areas will be an ever present possibility along and south of the 'ghost of a boundary' remaining. Thursday afternoon the first true winds will develop from the SE-SSE and nearly parallel the coastline all afternoon as the boundary washes out, with the remnants moving well off to the east and south.

Elsewhere, expect to see a developing squall line forming early Thursday morning over East Central Texas to move almost due east through Friday noon, accompanied by strong wind gusts. The squally line will be merely the 'tail' of linear forced ascent to the bodily component of a mixed bag a wind field parameters (helicity/vorticity) and various gradients combined to produce flooding rains (accompanied by melted snow) over Tennessee and Kentucky (at least), with some rotating storms over most of Arkansas, NW Mississippi, Western Tennessee.

I'll be interested with this 'event' to see what the Tornado warning vs. observed quotient will be. This might be an event where radar sees a lot of rotation in storms, with very little of it actually reaching the ground. Hopefully, that will be the case.

THURSDAY NIGHT: Warm (as over nights go this time of year) with a low in the lower 60Fs, perhaps mid-60s east coast south of Daytona. Muggy. Tempted to through in a good old 10% chance of a shower along A1A from the Cape to Miami from 5am - 8am as winds transition to more of a more SSW (from a S component), but that would be it for the rain chances any where or time.

FRIDAY: Winds becoming SSW and breezy with gusts to near 20mph South Central to North Florida. Less so over South Florida. Warm, much like it was on Tuesday, but thinking it will be even warmer by a degree or two most everywhere.

SATURDAY: What's left of the cold front that will be making weather headlines beginning overnight tonight (in some schools of thought it already is)...will sink into North Central Florida. Starting to look like this front won't get much further south of a Daytona Beach - Crystal River line)....but going into the later in the weekend it could sink to the Beach Line area. Still too soon to say, but my guts screams, "No it won't!". This front will have made headlines through issuances of Tornado Watch boxes, Flash Flood Warnings, etc within most of "Dixie Alley"...only the Pensacola area will be able to recognize this system's fomer self in Florida...although anywhere along I-10 could experience a "whopping rain shower" or two while the meat of the system exits off the NE U.S. Coast accompanied by a plethora of precipitation types and wind as far south as East Central Georgia where the squall line will whimper and fizzle out.

SUNDAY: Another warm day as the first of the two storms systems that will be impacting the Deep South enters Florida. During this day another significant "Dixie Alley" Storm System will already be in progress. This one will be a "high areal coverage /short duration impact" event for that region, affecting the some folks as the previous system. But it will be a fast mover, and currently appears will be just one big squall line. Too soon to say for sure at this point in time.

BEYOND: First chances of rain above 10% looks like would be Monday of next week as a front has been forecast through several model run cycles to cross all of Florida to reach the straits by Tuesday. We'll see, and even if this does occur, rest assured, no big temperature drops. In fact, if this front does get through as forecast it will take temperatures down to seasonably normal climatological values (from the above average we've been experiencing for the most part).

No comments:

Tuesday, February 22, 2011

13th Anniversary of the Central Florida Tornado Outbreak







IMAGES:(1)Video grab image was captured during the evening of Sunday night February 22, 1998 at 11:51pm as the deadliest tornado outbreak in recorded Florida History unfolded. This is looking north from Windermere at a distance from a distance of about 5 miles, backlit by frequent lightning flashes. (2) Aerial view of the Ponderosa RV Park in Kissimmee (3) General area of what is known as "Dixie Alley" (as opposed to the more well known "Tornado Alley" of the Mid-West and a portion of the Plains states). High lighted areas shown are for my personally annotated areas of tornado risk from early Thursday through Friday afternoon. Other areas of severe weather potential are not shown.

Tonight and early Wendesday mark the 13th Anniversary of the most devastating tornado outbreak in Florida history, both in terms of deaths (42), injuries (over 260), and damage costs. The first tornado touched down at 10:55pm on that fateful Sunday night, the last occurred around 2:27AM stricking at Port Canaveral. Personal video of this storm as it approached (one mile from tornado touchdown) is shown here:

http://www.youtube.com/watch?v=24iY95IRerA

You can "Google" on: central florida tornado outbreak 1998
(copy and paste that string into a search engine for more details). Also, if reading this post from the blog page, or perhaps email, you can click on the title line of today's post for an indepth description of how the chain of events leading up to this event from beginning to end unfurled.

FORECAST PORTION OF TODAY'S POST:
TODAY: Very warm today with a SW-W wind, breezy during the early afternoon with gusts up to 20mph. Highs all along the east coast will reach the low-mid 80s under partly cloudy skies. Winds over North and North Central will become more WNW-NW and decrease by late afternoon toward sunset as weakening surface front sinks south.

WEDNESDAY: Front boundary will have sunk south through North Florida and will be across Central Florida at sunrise, very close to a Port Canaveral to Brooksville line. This boundary is almost completely discernible only through analysis of the thickness values and some strung out moisture in the lower/mid levels of the atmosphere. There is no surge of cold air with the boundary, although temperatures on Wednesday will be a few degrees cooler (3-5 degrees) by that of yesterday and today except over South Central and South Florida due to the northerly flow and possibly more off and on again clouds, especially Central Florida. Winds on Wednesday will be lighter and veer from a more NNW-N direction toward the NE by day's end.

Coolest temperatures on Wednesday will be along A1A from near Sebastian Inlet to Jacksonville due to light onshore winds across cool Atlantic waters with highs in the low-mid 70s (coolest from Port Canaveral and North). Inland temperatures will be close to 80F away from the east coast, with warmest temperatures over South Florida (low-mid 80s) with less overall clouds other than diurnal pancake cumulus clouds.

THURSDAY: Could be a foggy morning once again (like many have been the past few mornings in the most favored areas given each morning's particular synoptic regime). Winds on Thursday should become more easterly with similar to Wednesday's temperatures although perhaps a bit cooler over SE Florida by only a few degrees. Any rain showers should remain to the east over the Gulf Stream.

THURSDAY NIGHT/FRIDAY: Although high pressure will have been for the most part in full control the entire time frame, the center at the low levels will become more situated to the east and south of Central Florida providing for a more Southeasterly flow, gradually veering to the SSW on Friday afternoon. Another warm day for all of Florida Friday-Saturday to SW winds...including the East Coast. Any rain showers (the silent 10 percent) to occur will be during the transition of winds from ESE-S which will permit the weak Gulf Stream moisture gradient to press on shore before washing out altogether.

Otherwise, other than a cooler afternoon for Wednesday/Thursday along the North Central and North Florida East Coast (perhaps as far south as Sebastians/Vero by Thursday morning) and some areas of fog once again, no significant weather issues. A similar cycle appears will occur some time over the weekend with the first front to possibly pass through in accompanied by a 20-30% chance of showers sometime around the 1st or 2nd of March. Overnight lows along the east coast will be in the 60s with some mid-upper 50s inland during the entire time frame.

LASTLY: I've thrown in the third image showing "Dixie Alley" (the brown shaded area) for a reason. It appears that the first broad severe weather event in 2011 for this region will unfold Wednesday night (late) almost anywhere over Oklahoma which will broaden and more significantly begin to show its true colors after daybreak Thursday.

Rapid changes will be underway at this time as an upper trough moves into the southern Plains and over a strong southerly jet of 40-50knts which will be overspreading the warm sector of North Texas (east 1/2) and Oklahoma. Although these storms will be elevated and capping (warm air aloft) could be an issue, some large hail might develop.

The bigger severe weather threat will develop from the Arlatex up to SW Missouri as cooling aloft associated with the 500mb trough overides warm sector air spreading east during late morning into Thursday afternoon in conjunction with a surge of a dry air from the west (a developed dryline). Instability won't be tremendous, but shearing wind profiles and turning of them with height as well as forcing for ascent along the dryline surge and in the vicinity of the warm front will be more than ample to favor the development of supercell thunderstorms and bowing line segments with tornadoes possible. I've highighted the original areas most likely for this activity initially (in regards to possible tornadoes) as well as where it could exist (with perhaps a bit less 'vigor' as the system moves east going into early Friday. There will likely be an enhanced "threat" area that can be determined once this synoptic scale set up actually materializes and mesoscale boundaries result once initial activity gets underway.

Tornado Alley, although more well known than "Dixie Alley" is actually where most tornado deaths occur due to the land scape (a lot more trees/hilly) and greater overall atmospheric moisture involved, often making tornadoes rain-wrapped and/or difficult to see due to the geography...although not always the case contingent upon the exact location a tornado forms. Conditions will spread east through Friday into the Carolinas and Virginia of less overall coverage...but bears watching.

Would also like to point out that this system from late Wednesday night through Friday will only be the first of at least two more over the next 10 days to follow similar tracks and evolution. I'm actually going to be even more interested in the following system going into late weekend, early next week.

No comments:

Sunday, February 20, 2011

Stellar Day For The Races at Daytona - U.S. Pattern Change




Images: (1) First visible satellite image of the day shows the overall coverage of the most dense fog early this morning. Almost completely gone at 10:10am (as I type). What remains of the boundary mentioned yesterday is in part the case of the fog for mesoscale reasons beyond the scope of simple blog post. The lime green colors show where some very weak low topped showers existed at the time. One or two might have made it on shore, but quickly eroded after landfall. (2) Again shows the more overall coverage of fog (within the yellow). We see there was more fog than satellite showed, due to the fact it was less dense (very thin) and very shallow. We see a bubble high near Tampa which is drawn to depict where a High Pressure is center when averaging out all the winds from the surface to 700mb. There isn't actually a surface high there. I've annotated a ridge axis extending north from the high for the reason shown in the fourth image (3) Indeed, the KSC sounding shows the shallow inversion was only at about 500 ft or less, with a secondary inversion around 4000 ft shown by the lime green line; and finally (4) forecast for 9am this Sunday morning shows the actual extent of the surface high up the East Side of the U.S. into Southern Canada, with what remained of the boundary over the East side of Florida, which will wash out after noon. We also see a low pressure system over SE Nebraska. The harbinger of things to come going into later in the week through the remainder of the month (see last paragraph).

Below are some surface observations recorded over East Central Florida where the most dense fog existed. We see observations down to 1/16 of a mile in Brevard County right in the ashes of the dead boundry:

ORMOND BEACH FOG 54 54 100 CALM 30.17 VSB 1/4
DAYTONA BEACH FOG 54 54 100 NW5 30.17R VSB 3/4
JFK SPACE CTR FOG 61 61 100 NW1 30.15R VSB 1/16
TITUSVILLE FOG 55 54 94 VRB3 30.15 VSB 1/16
CAPE CANAVERAL FOG 60 60 99 NW3 30.14R VSB 1/4
PATRICK AFB FOG 60 60 99 NW5 30.15R VSB 1/4
MELBOURNE FOG 58 55 90 CALM 30.15R VSB 1/16
VERO BEACH FOG 57 57 100 NW3 30.15R VSB 1/4
FT PIERCE FOG 56 56 100 W3 30.14R VSB 1/4

TODAY: Fog is burning off now, and will gone by the time this post is completed. The high pressure ridge axis shown in the 4th image above will traverse across the state today. Net affect will be conditions similar to yesterday by all appearances, although the overall synoptic situation will be a bit different. East coast sea breeze will again set up this afternoon with coastal temperatures along and east of A1A north of Sebastian Inlet in the lower 70s, mid-upper 70s the further one gets from the coast and south of Sebastian. Warmest on the west side of the state with a few low 80s here or there, although some locations may still get a sea breeze there within the closest 1/2 mile to the Gulf due to the fact that pressure gradient flow might not be strong enough to over come the thermal gradient created as the interior warms. Could be a bit hazy today with the ridge over head at 4000 ft. (shown in the above image) most of the day with high dew point air at the surface. Most clouds at least through early afternoon will be over Eastern 1/4 of South Central Florida into Palm Beach County.

Looks like it will be about 74-77F degrees today under clear skies with a light ENE wind around 10mph at the race tracks today. They're gonna "Zoom Zoom, zoom a zoom" (as the old PBS children's show sang).

Only change in the overall weather today will occur near sunset as winds at the coast become more ESE to SE after dark as the ridge shifts east and into the Atlantic, but remain under 15mph under clearing skies. Only locations that might see some breezes stronger than 10mph will be near I-95 where greater mixing of warm inland temperatures and the sea breeze will exist

TONIGHT/TOMORROW/TUESDAY: High pressure continues east and shifts the averaged locations south (from the position shown near Tampa this morning) south. By Tuesday it will be closer toward the Eastern Bahamas. Winds veer toward more of a southerly direction over night, keeping A1A temperatures in the low 60s overnight with upper 50s inland under clear skies. Might be some patches of morning ground fog inland, but not expecting it nearly as extensive as was realized this morning

PRESIDENT'S DAY NOON-TUESDAY EVENING: Winds become more assuredly SSW veering to W on Tuesday. Overnight lows begin to warm inland toward 60F. Afternoon highs along A1A finally reach 80F-83F degrees in the absence of the sea breeze with some areas near the North side of the Big Lake toward South Brevard maybe seeing a mid-80F reading with a spine of similar spotty readings up to Jacksonville near to just east of I-95 of similar nature. A cold front will be sinking south into North Florida during this time frame and settle into Central Florida overnight Tuesday into Wednesday. The immediate Gulf Coast side of all of Florida will be the coolest in the afternoons due to a Gulf Breeze in this SSW-W flow from west of Punta Gorda to Apalachicola.

WEDNESDAY: Front relaxes over Central Florida and begins to undergo frontolysis. Could be another morning of wide spread fog Wednesday morning as surface winds should greatly diminish by later Tuesday afternoon into early Wednesday within the bounds of the decaying boundary. Skies partly cloudy but not expecting any showers. Any showers with the front will be confined to Northern Portions of the state. Overnight clouds might hinder fog formation altogether, but this will need to be watched for the early morning road bound folks.

THURSDAY: Repeat of the cycle experienced yesterday (or similar to it). Boundary washes out and withdrawals its remnants into a brief appearance as a coastal trough, light on shore winds near the coast will bring down A1A temperatures to those that we are all familiar with by now up and down the east coast Thursday afternoon. Winds begin to gain a more southerly component overnight Thursday into Friday. About the only other notable change nearly state wide going from Wednesday and beyond is warmer overnight lows inland (at or above 60F).

FRIDAY: Could be another warmer day with highs in the lower 80s once again most everywhere except the west coast. A cold front will be sinking through the state later Friday into Saturday which currently appears will wash out in similar fashion on Saturday in similar fashion to the one on Wednesday, but just how far south this one will be able to penetrate is a 'hung jury', but it looks like this one will get further south.

THE PATTERN CHANGE: In the broad scheme of things concerning the U.S., a more zonal flow will be setting up with storms tracking across north and Central portions of the Deep South into the Mid-Atlantic region for quite some time to come, whereas high pressure protects Central and South Florida for the most part throughout the duration into the first week of March.

>Of interest will be that this establishing weather pattern will first become apparent beginning late Wednesday and beyond (although it actually began yesterday and is ongoing near the drawn low pressure in the image above) as storm systems begin to affect NE Texas, Eastern Oklahoma, Eastern Kansas, Missouri, Arkansas, Northern Mississippi and Louisiana, and skirt through the north 1/2 of Georgia, through Tennessee and Kentucky, and reach the east coast most notably in South/North Carolina and the Virginias. We will be hearing about tornado prone areas during this time frame, with each consecutive storm track getting further east and south with greater intensity...eventually brushing the Panhandle and the I-10 corridor in the process with at least better chances of rain. Looking more and more like Central and South Florida are more fully entrained in a 'dry season' regime for quite some time to come. Not good, considering the worst of it is usually not until April.

No comments:

Saturday, February 19, 2011

Splendid With Plentiful Sunshine Today



Images For This Afternoon: (1) Early-mid afternoon time frame in the first image shows a Florida Peninsular thermal trough forming up and down the spine of the state under abundant sunshine underneath a zone of high pressure ridges at various levels across Central Florida. High pressure near Crestview, and a weak backdoor boundary pushing SW across Jacksonville undergoing frontolysis as it approaches Daytona Beach. (2) Second image is for 7pm this evening. Boundary has about undergone complete washout with only vestiges of its existence evident by investigation of thickness values from the low-mid levels of the atmosphere and mid-level moisture convergence.

TODAY: If you liked yesterday, you'll like today even more. Believe there will be less clouds today than yesterday inland with similar temperatures. Under nothing but high pressure axis' aloft, a low level thermal trough (of warm surface temperatures) will establish this afternoon up the spine of the state inducing light afternoon sea breezes to form on both coasts. Afternoon highs within 1/2 mile of the coast will hold in the low-mid 70s, upper 70s to +/- 2 degrees of 80F away from the coast about anywhere. A few more clouds over North Florida closer to the boundary and over South Florida further from the precise ridge axis.

TONIGHT: Light coastal NNE winds will veer gradually across Coastal Central and South Florida as the boundary reaches to about the Port Canaveral/Crystal River zone by sunrise and remains there for the remainder of the day, Sunday. A bit of remaining moisture convergence along this boundary will produce a few more clouds than what we are seeing today, with maybe a spit of rain from the Port of Canaveral to those near Miami, but any thing to fall won't even wet the ground. I'd give the chance of even this to occur a silent 5%.

SUNDAY AFTERNOON/EVENING: Boundary will dissipate entirely as it lifts off to the Northeast Sunday during the afternoon some time and winds turn more southerly overnight toward the ESE-SE overnight. Warm overnight lows along the coast in the mid-60s to near 70F SE Florida. Sunday will be a transition day for what's to come Monday through the first portions of Tuesday.

MONDAY: Partly cloudy with some cumulus clouds and warmer along A1A from Vero Beach to JAX with a SSW wind (minus the sea breeze). Southeast Florida (along A1A) might have a sea breeze on Monday...which will temper down the high temperature there a whopping 4 degrees, no big deal. Inland areas will remain status quo with highs within 2 degrees of 80F, but favoring the plus side of it everywhere. Wouldn't be surprised to see some mid-80s near Okeechobee into the South half of Brevard. Overnight lows might be a bit cooler overnight but nothing signifcant, (upper 50s coast, continued mid-upper 50s interior) due to an overnight land breeze. Monday might be the warmest day of the week for North Central to Central (east side).

TUESDAY: Another warm day everywhere. Some rain showers possible North Florida and near the Keys into the Kendall area due to the mere pressure of atmospheric moisture, much less likely south than north though. A cool front will be sinking south into North Florida, but winds North Central to South should remain WSW-W all day with another day in the low 80s, maybe even some mid-80s today the east side of South Central. Partly cloudy. Thickness values will be falling during the day Tuesday with the approaching surface front, so those combined with more clouds might keep the temperatures in the afternoon down a bit from those on Monday..by a whole 1-3F degrees.

WEDNESDAY THROUGH THURSDAY: Boundary/stationary front will sink to the good old dividing line of North Central/South Central Florida (roughly along the Beach Line to Orlando, picking up along I-4 to Tampa) during this time frame. Expect partly cloudy skies, sometimes mostly cloudy and not as warm anywhere due to lower thickness values and more clouds. For now, a silent 10% chances of a shower, but wouldn't be surprised to see official forecasts announce 20% chances valid for somewhere between late Tuesday through Thursday anywhere over Central or South Florida by the time we get toward Monday morning. Regardless, no big cool downs...back to temperatures in the mid-upper 70s ...closer to 80F SW Florida... back to lower to mid 70s north of Ft. Pierce along A1A.

Between Wednesday through at least early Friday it currently appears we'll be dealing with a surface or low level boundary/feature across central portions of the state consisting of something between a stationary front across Central translating into a coastal trough just offshore which 'could' create more clouds along the coast specifically from Miami to Daytona at times (maybe a shower as well specifically along the coast south of Vero Beach, all of South Florida, Keys overnight to early morning).

FRIDAY: High pressure reasserts itself from the south as whatever boundary we have left washes out and southerly flow becomes the predominant low-mid level feature. Warmer temperatures and partly cloudy with coastal lows in the 60s, afternoon highs near 80F.

No comments:

Thursday, February 17, 2011

Other Than Some Clouds at Times, Pleasantly Benign



Images: (1) First image: 9AM Thursday morning visible satellite image with the weak surface features sketched in. We see a very weak bubble low east of the Space Center with a weak coastal trough off shore annotated with the dashed yellow line (get used to those the next 10 days from time to time). This low has been meandering around the Cape since yesterday, and re-emerged (along with the coastal trough) after dark last night as expected would occur. Also shown is where fog still remained on the hour at 9AM, it was previously more extensive (within the yellow area). The lime green shows where some rain showers had been occurring at the time. The fuchsia lines show where the most extensive lower cloudiness resides. Note the clouds over NE Brevard county within the bounds of the surface low where winds are near calm (2) Second image shows the RUC forecast for roughly the same time. We again see the low analyzed by that model along the coastal trough, and the ridge axis running down through North Central/North Florida at the surface under which the most fog resides. The very weak surface low reflection (motion) along the coastal trough, shown by the black arrow, is in the of process of relocating further north toward off the coast of St. Augustine late morning as it starts to become absorbed in the much more prevalent high pressure over the eastern Carolinas into the Atlantic Ocean which is dropping southeastward.

TODAY: SKIES - Some more showers over SE Florida today will wash out by late morning with partly cloudy/sunny skies to remain as temperatures reach the upper 70s...perhaps an 80F here or there. The only bug-a-boo today over Central Florida will be the extent of the clouds over N. Central Florida (along and north of the Beach line toward Orlando). Satellite animations and personal observation since waking up this morning has shown that they are going no where just yet. Based on some model guidance trends, satellite/radar animations, and some half-witted experience, believe that some of the areas in the fog right now might transition to partly cloudy to occasionally mostly cloudy this afternoon...breaking up going into late morning but then reforming again as clouds with heating of the day. But from Cape Canaveral to Orlando it is very sketchy. Believe this area over East Central Florida will end up being partly cloudy with mostly cloudy conditions from time to time throughout the day...50/50 both modes but hedging more toward 70/30 for extreme NE Brevard County (70 being mostly cloudy). Further south will be partly cloudy to mostly sunny. Winds will remain light today, but believe a light sea breeze will form by mid-afternoon and push inland which could aid in clearing out clouds along the coast near the Cape. This boundary might act as a very weak lifting mechanism to form a line of low topped cumulus clouds down the spine of the state north of Lake Okeechobee later today that will slowly migrate toward the west coast then die as the sun sets before reaching the other coast (west).

SHOWERS?:Also, not so sure there won't be some trace rain amounts west of I-95 as the weak seabreeze pushes from Brevard County and north toward the inland locales where low level moisture is pooled and large areas of clearing skies currently exist. Should this transformation occur, the chances of even a spit will end after 5pm. Again, west of I-95 from near Orlando and North. Showers over South Florida should end before noon if they haven't already. Even so, most people won't even know a drop has fallen unless they are in the car and see the drops appear on the windshield.

TEMPERATURES: No big changes from those of yesterday. Mid-upper 70s inland after warming from the mid 50s this morning. A1A will be right around 68-72F from Cocoa Beach and north (most assuredly if the clouds remain. )...a degree or two warmer further south and into the mid-upper 70s from West Palm south.

FRIDAY/SATURDAY: More chances of fog in the mornings inland as high pressure ridge settles right across Central Florida in a very moist low level environment (dry aloft). No rain and temperatures running status quo to that of today. Coastal lows SE Florida around 72F, cooling to low 60s as one gets north of West Palm to Daytona Beach (A1A). Further inland morning lows in the mid 50s, afternoon highs in upper 70s. Coastal highs from Port Canaveral and north will be near equal to the coastal lows they will have from West Palm Beach and south (near to just above 70F).

SUNDAY: As mentioned two days ago, and is still be indicated, another backdoor wind shift boundary works down the Atlantic Seaboard from the Georgia Coast. Looks like this one's influence will remain offshore in regard to any rain chances, but could see an increase in coastal clouds Sunday sometime and a shift in the wind direction to NE. Either way, winds remain around 12mph or less throughout the time frame. This boundary does not affect SE Florida.

MONDAY/TUESDAY: Continued dry, but could see coastal high temperatures from JAX to Sebastian reach the upper 70s to near 80F along with the rest of the state, namely because this region on the east side could lose the cooling sea breeze. All other areas remain status quo, but could reach low 80s on the east half of the state just about anywhere north of Sebastian Inlet. Not so sure they won't hold on to an afternoon seabreeze further south, keeping SE Florida in the upper 70s.

WEDNESDAY: Frontal boundary moves in, and we look at a small chance of showers and increased cloudiness. In my mind, it's a bit up for grabs as to whether this front will quantify as a backdoor front or just a very weak 'regular' one. Either way, little impacts other than a shift in wind direction to NE right after passage of the boundary and the items noted in the previous sentence regarding clouds/showers.

BEYOND: Potential for a little bit more of a dynamic pattern to begin to emerge heading into late February/Early March. Even so, with the hints of what 'was' a very dynamic storm system to affect Florida in yesterday afternoon's GFS run (no longer shows this morning), the temperatures never fall much in the post-storm layout. In other words, no freezes or even frost the rest of the calendar winter for South or South Central Florida. So far. SE Florida can totally right it off though more than likely.

On this day in 1992 - 0920AM - Gulf County, Apalachicola - A small tornado lifted a car with three occupants up and slammed it down on the road several times. It blew the hatchback door up on the roof of the car. The tornado also uprooted trees and damaged two houses.



No comments:

Wednesday, February 16, 2011

Cloudy East/North Coast, Showers, Pleasant Elsewhere


Images This Morning: 1)Dotted yellow line shows what remains of the old 'back door' frontal boundary (see discussion below) and green areas show shower chances first part of today (dashed shows working into tomorrow) - also shown is a weak thermal low near Cape Canaveral; (2) 2M dew points at 9AM-yellow is highest dew point temperatures (3) Convective available Potential Energy (CAPE) values show highest CAPE just offshore the Cape (these are meager values, but nonetheless, exists\ there and are acting as a 'source region' for shower generation).

NOW: What remains of the inverted back door cold front discussed yesterday is positioned approximately as shown in the first image above. It never really made it as far south as was feared it would yesterday. As such, the Cape area never got 'back doored' by very cool marine air. It made it about as far south as the tip of the Cape where late afternoon temperatures went down to 59F...too close for comfort for folks in Cape Canaveral south. At that same time it was 68F degrees on my porch not far away. As noted above, the boundary made it about as far south as the tip of the Cape at KSC where it resides this morning. pushing inland across the St. Johns River Valley Basin of NE Florida. As we can see from from this satellite image, extensive low level cloudiness exits along and behind the boundary where richer dew-points (more moisture) resides.
Also noted this morning is a very very weak surface 'low pressure circulation' in the armpit of the Cape near Cape Canaveral to Cocoa Beach north of SR 520. This circulation will likely wash out during the late morning hours as it seems to be a function of ocean temperature differences between those measured north of the Cape versus those south of the Cape in an otherwise near calm wind environment. We also see the highest CAPE values offshore the cape (which are in part a function of dew-points and lapse rates). With the greatest instability (highest CAPE values) in that location, extensive low level clouds and light rain showers have been forming and moving onshore from the tip of the Cape northwestward within the bounds of the solid green line. In essence, this area is acting as a 'source region', at least early today. We'll see some changes in this configuration as pictured now as the day wears on.

A weak mid-upper level trough is passing over the North half of Florida this afternoon and across this surface boundary from west to east. This could, at a minimum, provide enough continued lift for more clouds and showers in a broader expanse than what I'm seeing now, but otherwise impacts remain minimal.

As I type this morning, with the sun having risen, cloudiness overhead my location has thickened - a drop or two of rain could come down at just about any time now. For the most part, any rain to fall today will be north of SR520 along and east of US1 through the earlier portions of the day, but that area should spread westward as shown by the dashed green line in the first image as the boundary tries to push on shore, more so in NE Florida where high pressure off the Carolinas has a greater influence there to push the boundary inland. Think that any rainfall "totals" would be 0.1" or less. Additionally, most of the rain through early afternoon to fall will be east of I-95 north of Cape Canaveral.

Otherwise, temperatures underneath the clouds today probably won't break 70F degrees, whereas the remainder of the state will reach the mid to low end upper 70s under partly cloudy skies. Overnight lows as expected fell into the mid-50s in general most areas, with the coolest reading at Tallahassee at 36F and along interior portions of the West Coast where temperatures were in the 40s. Some of those same areas today will also be the warmest though with less clouds and a land breeze north of Sarasota. Coastal lows from JAX to Miami were 57F-63F in general.

TONIGHT: As high pressure builds a bit further south and the near shore Atlantic surface winds become more ESE, but remain light (10 mph or less), stronger offshore. Could see some regeneration of the coastal trough along the immediate coast from Jupiter Inlet north, and as the story goes, continued cloudiness overnight into early Thursday with a slight chance of a light rain shower within the area shown in the dashed green lines into tomorrow under those clouds. Rainfall, again, will be very light. Coastal lows in the 60s, mid-upper 50s inland. Very small chance of a spit from near Boynton Beach south as well tomorrow as the coastal trough develops overnight, but very minimal.

TOMORROW: Should start off the day over all of East Florida (namely east of i-95) as noted above through early afternoon. Looks like, as it stands now, with daytime heating or by early afternoon the trough will washout. Temperatures similar to today's. But just exactly when this will occur remains to be known, but it should be sometime tomorrow before high pressure strengthens across the Gulf and Florida, absorbing the boundary in the process.

FRIDAY-EARLY NEXT WEEK: Not seeing anything other than high pressure over the Gulf and Florida with no boundaries (other than thermally induced coastal ones on both coasts) under high pressure in the mid-upper levels. High pressure center aloft could shift more toward the Florida Straits going into late weekend as 500mb heights rise due to warmer air in the mid-levels moving in which would cap off any lifting mechanisms that would induce showers otherwise. Thus, after tomorrow (sometime) it looks rain free. Coolest afternoons along A1A up and down the coast, but also warmest overnights there as well.

Afternoon highs along A1A from Cape Canaveral north around 68F -73F, peaking out early in the afternoon before a light sea breeze sets in. Overnight lows from Cape Canaveral south in the low 60s warming to the mid-upper 60s south of Ft Pierce going into the weekend. By the weekend morning lows from West Palm South might never get below 70F, essentially equaling the water temperature. Afternoon highs will also get into the low 80s on various days late weekend going into next week in the locally preferred areas on any given day, but those areas will likely have to be at least 1/2 mile from the coast.

Very generally, temperatures will be close to normal afternoon highs/lows everywhere whereas the immediate coast could be above normal by 4-8F degrees for morning lows. Very little in the wind department, less than 12mph throughout the time frame.



No comments:

Tuesday, February 15, 2011

An End To Lows Below 50F Begins

Image: Forecast for 9AM this Tuesday morning shows high pressure building SE into the Mid Atlantic ocean through the rest of the week as noted with the black arrow. Leading edge of the influence of this high pressure area is highlighted by a 'back door' cold front as shown at 9AM to be crossing the Jacksonville, FL area pressing SSW through late morning into the early afternoon.

TODAY: As noted above, a 'back door' type cool frontal boundary will cross much of North and North Central Florida today, then slow down and stop somewhere across Central portions of South Central Florida, never reaching South Florida in the short-term. NW winds this morning will begin to veer toward north late-morning and shift to NNE-NE and pick up a bit this afternoon following passage of the boundary across the NE quadrant of the state, mostly notably along the east coast from near Satellite Beach north to St. Augustine. Otherwise, few clouds will be noted.

The benefit of this boundary in passing will be higher dew point temperatures (more moisture in the low levels) advecting from east to west across North and Central Florida, most notably after 1pm today and beyond. Dew points in the 50s will eventually advect in across much of the area progressively from NE through SW beginning shortly after noon time through this evening and into Wednesday as high pressure moves off the Mid-Atlantic coast and begins to settle a bit further south over the Western Atlantic waters well off shore the state by several hundred miles.

TEMPERATURES TODAY: The only fly in the ointment for today will be the afternoon high temperature from near St. Augustine south to Satellite Beach, especially (and in a more focused area) from near Ormond Beach to Port Canaveral to just north of Patrick AFB) east of US1, and especially along A1A. As noted, winds between 11am - 1pm will veer to a more N to NE component approximately around this time frame and usher in higher dew point temperatures.

However, these winds will also be blowing across sea surface temperatures measured yesterday off Daytona Beach that were 55F. Ugh. The wind shift will be most notable during peak heating, especially around 2-3 pm through the remainder of the afternoon as full sunshine heats the atmosphere and stronger winds at 2000ft mix to the surface (ground level). These winds will advect (or "push in") the very cool air to those folks, mostly affecting residents along and east of A1A north of Cocoa Beach. But to what 'degree'? The 'degree' I'm thinking of would result in a high temperature in the low-mid 60s, perhaps falling into the upper 50s between 5-6pm as the sun gets low.

I've noticed on satellite based sea surface temperature estimates that south of Port Canaveral (and as measured off of Cocoa Beach Pier) that water temperatures there are 60F and above (warmer the further south one gets). But again, as noted, from north of Port Canaveral waters were 55F. The warmest near shore waters are from Ft. Pierce and south where the Gulf Stream is much closer to shore.

So in essence, the gist of my post today hopefully reflects an interest in seeing just how cool it will be this afternoon, even with a warm up earlier before noon time. Of interest as well, is in noting that the official forecast is reflecting highs in the upper 60s on the coast, but be advised, yesterday afternoon while most areas were 70F degrees...the readings on the KSC mesonet along the eastern points of the Cape just north and east of the Port Entrance at Port Canaveral were 59F with just a light 5mph NE wind at that time.

So you see, with a stronger NNE-NE wind (12-20mph just offshore) later today, why my 'interest' is perked. Just to be safe, if you're planning to head to Playalinda Beach, Ormond Beach, Daytona, or The Port from inland areas...I'd bring a jacket.

TONIGHT: High pressure will move well offshore the Mid-Atlantic Coast and sink a bit south, whereas another area of high pressure will build northward from the Gulf of Mexico. Between these two entities at play, surface winds overnight will veer more from northeast to from due East and blow off 60F degree ocean waters from the Port and South. Therefore, there will be very little temperature variation between the 'post - 6pm' temperature and that which will be felt Wednesday morning along A1A, with a low in the upper 50s. Inland temperatures will fall into the -mid 50s, coolest over the west side of the state...perhaps even toward Sarastoa where the dewpoints will be last to warm and they'll have an overnight land breeze.

WEDNESDAY: Prolonged onshore flow will have lifted low level atmospheric moisture levels to the level ample enough for cloud generation. As such, believe that overnight (tonight after midnight) some stratocumulus clouds will be begin to move in, providing further reason for overnight lows to remain warmer in the absence of any radiational cooling/dry air/clear sky conditions/calm winds. As noted in the post on Sunday, and will repeat in the post this morning, I will throw in a "silent 10%" chance of a light rain/sprinkle from shortly before sunrise through Wednesday from Sebastian to St. Augustine...silent because any 'rain' , per se, wouldn't hardly be enough to wet the ground.

The majority of Wednesday appears will be party cloudy, and at times, mostly cloudy with the sun still peaking out in the absence of anything but low, stratocumulus clouds. As mentioned, winds on Wednesday will be almost due east, so expect highs to be in the upper 60s (between 67-69F) east of State Round 3 up and down the coast of Central and South Central Florida, with low-mid 70s west of I95 from Central Brevard south to Miami (and the Keys). Again, though, the fly in the ointment for coastal North Brevard and Volusia County will be the extent of clouds combined with the wind (lighter tomorrow than this afternoon) along A1A, over Volusia and Flagler County...and north of Canaveral Air Force Station. Could still be flirting with low-mid 60s there. South Florida, no problem in the never ending non-changing weather pattern. Very pleasant there, but with some clouds.

THURSDAY-FRIDAY: Surface winds will begin to veer a bit more toward the ESE-SE and remain very light. Overnight lows along the coast in the upper 50s, approaching 60F on Friday along A1A. Cooler west of A1A with lows in the mid-upper 50s. What is left of the backdoor boundary could shift further south by Thursday due to a secondary resurgence of high pressure to shift the chance of light rain spits further south toward West Palm to Miami on Thursday. Otherwise, very pleasant with inland high temperatures in the Mid-upper 70s, with the coast hovering closer to 68F....must say, I want to say 70F because it sounds good, but don't think its going to happen along A1A north of Patrick AFB.

WEEKEND: Looks like another back door boundary will come through sometime on Saturday. This has been shown by the GFS to occur for several days, even while it was showing this initial one today, so this is no surprise. The net affect with this boundary, initially, will be to back surface winds to NE for a brief time over North Central and Northeast Florida...with a return to conditions similar to what will occur later this afternoon. However, this time the high pressure will rapidly settle in further south with return surface winds from more of a southeasterly component.

Meanwhile, while this is all going on late this week and into the weekend mid-upper level high pressure will be building NEward from Southern Mexico and into the Central Gulf. Remember my writing several days ago that we would be under the influence of high pressure for quite some time after we cleared of the rain/ cloud producing cold front early last week? And it would be the 'source' of the high pressure that will make the world of difference in our local weather?

Well, this high pressure source from Mexico will be the clincher going into early next week. That is to say, instead of messing with modified North Pacific/Continental high pressure like we will be through the remainder of this week, we'll be messing with High Pressure from the South/Central waters of the Pacific at the surface and aloft combined with those of the Gulf of Mexico.

Net affect, no matter how one looks at it, warming in the mid-levels will bring abundant sunshine with partly cloudy skies...highs in the upper 70s by later this week and into next week continue...with some low 80s in the far interior portions of South Central and South Florida. Overnight lows in the low 60s coastal, mid-upper 50s inland.

Finally, even our Tarot Card Dealing Crystal Magic Ouija Eight Ball is not showing any cold fronts to impact Central of South Florida through the 1st of March and beyond. Does this mean we'll not see another cold front the rest of calendar Winter? No. Some cool downs could still occur. And the chances of severe weather due to frontal systems/low pressure still remains through mid-late March. Remember now, we had Severe Weather Awareness Week when it was (last week) for a reason, so that folks woiuld be prepared, reminded, and forewarned of the upcoming periods of potentially active (or severely inactive) weather extremes.

In some posts the remainder of the week, I'm going to try to remember to include some examples of what has happened in the past over Florida between Mid-February through March. You might be surprised to see what has happened in the past during this time frame, considering what the weather outlook is showing for the next 10 -14 days. But for a hint, don't forget the "Super Storm" and the worst Central Florida Tornado Outbreak in Florida History in the 1990s.

No comments: