Statewide Thunder/Lightning Spell Commences Today With Points of Interest

Image and "Points of Interest" are only for general purposes as a depiction. Localized effects and usual storm and 'wind boundary'  interactions will dictate the overall rain coverage outcome as the day wears on, and determine overall heaviest storm activity and rainfall totals

TODAY: As delineated yesterday, today marks a full  turn in the pattern of past days. Plentiful moisture and moderate to nearing strong low level instability with light steering should result in plentiful sea and lake breeze interactions. One fatality occurred as a result of lightning and one from rip currents the other day, so beachgoers beware especially during the outgoing tide after 11:30AM time frame through mid afternoon. Also nothing that depending on where first activity goes up and how strong it is, the resultant collapse and cooling outflows of said activity could clear out fairly large areas from ever seeing rain in those nearby areas.

NOW: Latest KSC upper level sounding shows a 10kt wind from just above ground to 3000 ft. . This should (if correct and remains that way) hold off inland east coast sea breeze penetration to much of a degree until early afternoon, but allow a very shallow one to form). The next effect 'could' be for activity to begin to form very close toward the Cape Kennedy area. With such light winds just above that level (less than 6 mph)...funnel clouds in any newly forming activity are not entirely out of the question should something manage to form that is. Same might hold true for activity near Lake Okeechobee's coastal counties, if not more so. Otherwise, both sea breezes will work inland today, but exactly which one will be the most dominant at this time is impossible to say for sure if either one is in fact dominant.

TODAY: Ultimately, today will be a very typical summer day of storms with happenchance showers and storms forming indeterminately at first but grow in coverage and strength into mid-late afternoon. Be on guard for the first showery looking activity which so far is not shown to form until early afternoon after 1pm. The first bolts of the day can prove to be the most 'deadly' (although all bolts are) as they are not preceded by earlier forebearers  of warning. By late day it becomes more obvious. 

Funnels could be possible today, if not a landspout type formation, but those are way too far and few between to include in most forecast packages from the NWS. Most areas could be clouded over by sunset other than some coastal areas toward North Florida. 

BEYOND INTO TUESDAY: We might squeak out another state wide active day through Tuesday. Guidance seems to imply a weak tropical wave like entity passing across around Wednesday making for early day coastal showers on that day and perhaps a day or so after that as well. Otherwise, it's a call it as it comes forecast situation. The only other out of this norm is that around Saturday or Sunday the SW steering might greatly hold off the east coast sea breeze if not entirely one or two days, especially north of the Cape area if not as far south as the Vero Beach area...or limiting it too a very shallow sea breeze to within one mile of the coast. Those will be quite warm and muggy days no doubt for even the beaches. Slap on the tanning butter' Rock Lobster'.

Pattern Change Underway Now: Interior 'Strong' Possible

Details on the Pattern Change in the body of this post. For today, better sea breeze convergence and cooler air aloft  should result in a fairly typical summer like weather pattern just 5 days after the calendar first day of Summer on June 21st and 2 days after the first full moon of Summer 2013. Rip tide danger is in place as well as a result of abnormally high tides translating to very low tides during peak swimming hours   

TODAY: After a respite from active weather except for a few events along the west coast, a pattern is underway unbeknownst to the non-weatherized at the time of writing. Steering currents would or could favor more toward the east coast even more than what will result (today) if not for a bubble high that appears will translate across North Florida later today which will change the steering away from the immediate east coast (although it will be very light) mainly north of the Vero - Sarasota line. 

Sea breeze and lake breeze boundaries coupled with cooler air aloft (than normal) accompanied by plentiful surface heating and moderate low to mid level instability (CAPE) could result in a few stronger storms along boundary mergers with frequent lightning , tiny pea hail within the heaviest downpours, and wind gusts toward 50mph or so. Most of the stronger activity appears would occur in low populated areas today for the most part as well as remain fairly isolated, but come the 5 o'clock witching hour when LCLs (lifted condensation levels lower) - whatever area of potential not already scoured out by a sea or lake breeze or stabilized by earlier rainfall could experience a big storm , especially around 5:40pm -7:15pm (inland).

THURSDAY- MONDAY: So far, the last few GFS runs are consistent with the idea that the low to the mid-level subtropical ridge axis (aka "Bermuda High Extension") will loiter somewhere around Lake Okeechobee toward the Southern Everglades region..placing much of the state in a "frow the Southwest toward the  Northeast" steering flow, or in abbreviated form, "SW Flow". Such a flow directs storms toward the east coast late in the day, but given the warmer Gulf waters, would expect the west coast will experience a somewhat active period as well, only earlier in the day.   

BACKGROUND SYNOPSIS: For a number of days large thunderstorm complexes have been raking through the Great Lakes region in association with a developing trough in the upper levels. High pressure (heat dome) to form over the Desert SW Region will amply amplify  to complement the aforementioned trough to 'slide down the front of the ridge'..or 'deepen' or 'build south'...the result will make for much thunder activity almost perfect east of the Mississippi River area and more so toward the I-95 up and down the U.S. east coast. Many east coast locations with the sea breeze front could experience some stronger storms, with the Florida Peninsula magnified at times because of not one but two sea breezes colliding with each other. Resulting in a ridge over the west half of the U.S; Trough, east half. 

By Saturday or Sunday the SW steering and surface winds as well might get strong enough to hold off the sea breeze altogether, but regardless, rain shower outflows might still work in favor of activity. I suspect we'll be hearing of rain chances between 40-60% most days.  Other days, the west coast sea breeze will work well across the state only to "meet and make its East Coast Sea Breeze storm Maker" closer to if not east of I-95.

Some activity could linger into mid to late evening   several of the upcoming evenings as decaying thunderstorms in the form of light to moderate rain and night time lightning displays crawling through cloud tops in the mid-upper levels run their course. 

This pattern over all can be seen more clearly to develop by the image above of the  duplicate/coupled mid-upper level flow come Saturday into Sunday (below)...Ridge to the west; trough to the east.

So far, it looks like this new to come pattern 'in the Now' is to fold out and relax overnight Monday into Tuesday resulting in a deep SSE-SE Flow but a moist one which could make for east coast morning rain showers and westside thunder heading into the first full week of July.

  

Iso-Strong Storms Possible Mainly South Central Late

Loose-Leaf image of possible rain and thunder activity today. Although the region over Central -Central is questionable, more likely chances are further south.
(pardon the graphic typo)

TODAY: Very warm to nearly 'hot' by comparison as it is starting to feel like summer more and more each day. Best chance for storms today appears to be from near YeeHaw Junction and South (Southern Osceola County) but earlier visible satellite imagery showed a cloud line well out in the Atlantic extending across the Cape near Canaveral and inland a bit which now has dissipated. 700mb analysis indicated a weak trough associated with that line, which likely will not move much today , so it could act as a trigger later today as the east coast sea breeze develops. Expecting only slow inland progression of that boundary, thus any sea breeze collision should be quite late today into early evening toward the east half of the state. Further South more boundaries to play with considering  the "Okeechobee Sea" can develop it's own breezes. There might be another nice sunset tonight for viewing purposes, as was witnessed last night.

FRIDAY: A chance for Strong to Near Severe primarily from Volusia County and North, but some activity could inch into North Brevard or even Central by Dark or after dark. Tomorrow is a very interesting day with activity coming down from the NNW in general. The other region to watch will be far SE Florida.

BEYOND: End of pattern, New pattern emerges - as a frontal boundary will get about as far south as Lake Okeechobee before washing out. Most thunderstorm activity will be restricted toward the western  1/3 of the state and inland of the east coast down by Dade County for a day or two  until deeper SE flow works up the coast. From that point on models diverge so will not 'go for broke' in this post today to outlook anything than inland thunder and maybe a period of early day coastal showers as far north as the Cape around  Tuesday time frame.

Chance of Strong and IsoTempo- Near-Severe Thunder Later Today

MORNING CAPE Sounding showed colder air aloft this morning, and surface and mid-level based instability is also much higher today than the best several days. With a boundary in place near to north of I-4 which should drop toward Dead Central by early afternoon accompanied by late Day Sea breeze collisions suspect today could get rather active. Some storms could be briefly near severe or strong resulting in brief heavy downpours and small pea sized hail over hte interior. Sttering is quite light some most storm motions will likely be translation along sea and liake breeze boundaries with a slight drift toward the East to ESE, especially early on

Yesterday's Sunrise "Walkies" in Cape Canaveral Florida

TODAY: Morning sounding shows upper level temperatures much cooler that past two days, and current surface based instability already approaching 4000 CAPE (which is high and unstable), along with more unstable lifted index and cold air aloft accompanied by outrageous dew points and plentiful moisture aloft (but not too much)  could result in strong storms today with frequent lightning , maybe some small (non damaging) hail, and blinding rainfall along the interstates and state roads across the interior , especially after 4:30 -700pm over the interior. Light low level winds should allow sea breezes to work inland slowly but surely for a late day collision. There is a remnant surface boundary to 2000 feet that has snuck south toward I-4 which might act as an earlier than usually trigger, which could sink toward the 528 corridor later before dwindling out tonight. There is already a secondary extremely and barely discernible near 528  and riding up along the Cape as I type as well...extending west toward Tampa Bay.

WEDNESDAY: Hard to say for sure. Morning (early early on) models didn't really pick on the trend that is currently going on over the state, the RAP is just figuring it out hour by hour. Thus, guidance from last night could well be off for tomorrow. Looks like tomorrow through Saturday could stand to be a variation on a daily basis of the same theme, with one day (maybe tomorrow or Thursday) being a less active day. The previous post the other day highlighted the Thursday to weekend time frame for strong storms, and so far that still stands, but exactly where is still questionable.

BY SUNDAY OR MONDAY: Looks like a pattern shift that could last several days, meaning lower rain chances (mainly toward South Florida) for several locations.

Cape Canaveral on Monday Sunrise Surf 

Storms Today 'Could' Produce Frequent to Excessive Lightning

Thunder Possible in Orange, In Purple where there appears to be a
 chance of EXCESSIVE Lightning
in a few Storms as of noon time guidance

TODAY: Huge buckets of rainfall occurred over SE Florida yesterday along a trailing vorticity lobe of Andrea even though the storm was well far away. A remnant of that boundary is now, per visible satellite imagery (or at least appears to be) located along a line from near the tip of the Cape west to just north of Tampa Bay; another boundary is further north yet still running east to west, and one that has been active all morning over Palm Beach County extending west toward Sarasota or just south of there. Steering winds although now are about 15 mph from WSW - ENE , are forecast per short term RAP model information to weaken to 8-10mph much later today except in the tallest of storms, in which case up to 12-15 mph could occur.

Sea breeze inland penetration is iffy, as cloud coverage in certain areas could offset it (such as over far East Central Florida). 

It should be noted that the least favorable area for storms at the current time of this writing is East Central Florida. Lifted parcel levels (LPL) are way too high, there is virtually no lifted index values (LIs), and CAPE (convective available potential energy) is weak compared to other locations . Thus, it is with a bit of hesitancy that such a brazen statement of high lightning threat is being made in today's Blog post; however, all indications in short range high resolution guidance (HRRR) insist this will be the case as the stable area of East Central erodes in the next few hours.  Additionally, lake breezes interacting with a west coast sea breeze working east combined with outflows from South Florida activity currently ongoing could result in a surging northward of interacting outflow boundaries working up the interior with a secondary area along the east coast sea breeze, especially and only if the timing is right (that is to say, after 4:30pm if not 5:30pm). 

It is possible with the chance that the steering will have weakened later today that storms further north of the Southern more counties will not press off shore, but rather anvil debris tops and/or light to moderate rainfall from decaying thunderstorms would be the result mainly East of I-95 with little more to speak of. Much depends on how far inland the east coast sea breeze can penetrate even though it should be a very shallow sea breeze. The other questionable detail is that the morning KSC Sounding showed a convective temperature of 92F, which is going to be a bit hard to come by in almost all locations with the cloud cover currently in place ; thus, unless that changes to somewhere around 86F storms in general would be hard to come by, but again, that sounding early today was also in the most unfavorable area as of early today as already point out. 

Winds at only 2000 ft today alone is expected to remain from the SW all today regardless of any seabreeze which would lead me to believe that the HRRR might be off on something in this regard.  Point is, high lightning threat remains so far today, which includes bolts well removed from storms and innitial bolts that can come down before rain even appears in certain locations. Lightning Safety Rules apply.

SUNDAY-MONDAY: Ridge axis near South Florida will be lifting toward Central Florida which will limit afternoon activity to well away from the east coast over Central Florida toward Orlando and west but closer to the coast along and north of I-4.

TUESDAY: The next trough from the Mid West region will begin to press the ridge axis back south on Tuesday or Wednesday as it enters the SE states coincident with the approach of a Tropical Upper Tropospheric Trough  (TUTT Low). Guidance has shown this to be the case for about 2 days now. It has been my observation that such interactions can result in isolated storms due to some drying but also stronger ones as well. That will be yet a new story and a totally different weather pattern to contend with from that of today and to a smaller degree, Sunday and Monday.

The ECMWF is showing steering to become again more from the SW rather than away from the East Coast as has the GFS in previous runs. It appears the GFS is trending toward there emerging somewhat of a 'backdoor like' front or mid level trough working down the the East Coast on Tuesday into Wednesday that could result in even early day activity near Volusia County working only slowly south with time (a bit like what is happening over Palm Beach County today). But that is still far away and will likely change.

TUESDAY/WEDNESDAY: TUTT low shown is at JET STREAM LEVEL, winds below this low will remain as if a trough is approaching through the lower 20,000 feet of the atmosphere.  TUTTs are notoriously difficult to forecast several days in advance at times as are the interactions with other subliminal lower level features.

Slight Chance of Showers And/Or Some Thunder East of I-95 Late Today

Orange and Green shows best chance of  thunder/showers respectively late today not including on-going activity as can be seen currently in this morning visible satellite image over South Florida

CURRENT: The "Circulation Named Andrea" is now over South Carolina. Note that at no time did any land observation location report Tropical Storm force sustained winds. As it cross the Gainesville to JAX area winds were sustained about 12mph. The winds were all well above the ground. Today, the strongest winds will remain offshore the coast to just on the east coast of the Carolinas and north, mainly as a result of pressure gradient with high pressure to the east of the circulation.

Can you find Andrea? In this image the center of the circulation is still offshore of Cedar Key near the Big Bend in the Gulf. Tropical Storm aloft. It is questionable at this point just exactly what is to occur next.

Andrea Bottoms out right about now,  seemingly becoming a bit  extratropical in nature as the storm begins to get absorbed in an upper level trough as was expected to occur

TODAY: What is left of the "Circulation Andrea" is to race up the east coast in the next 24 hours and within 3 days will be very close to Europe! Meanwhile, west wind most of the day with highs in the mid-upper 80Fs making for a nice day. It appears as the storm gets further away that the pressure gradient at the lowest levels will relax just enough for a sea breeze to develop after the latter portions of peak heating.

At this time, the mid-levels have really dried out, but a surge of some moisture from the west should be moving in to fill the dry slot late today about the same time the sea breeze can form. With just enough instability present and convergence along the coast east of I-95, this could result in showers and some thunder east of I-95. Thunder might even be east of US1 if not restricted to the Barrier Islands themselves with a little interplay along convergence of the north side of the Lake Okeechobee Shadow near Ft. Pierce area in general. Best chance appears would be after 5pm through sunset, working northward with southern activity working up the sea breeze from the south where it will develop earlier.

BEYOND: Rain chances look a bit better (higher) for Saturday but begin to wane Sunday - Wednesday as the ridge axis lifts to Central if not north of Central Florida making for early east coast sea breeze on set. Another trough will enter the Deep South by Thursday accompanied by colder air aloft, setting the stage for possibly isolated but stronger storms Thursday into the next weekend, but that is too far off to be for certain regarding coverage.

Sunset Pictures with Departure of "Andrea Circulation" were being spread across the internet and on TV last night during the newscasts 

"Eyes on Sunset"

Tornado "Potential" Could Increase through the Morning - Again Later Today

Early Morning Radar shows what was referred to in previous
 posts as a 'pseudo warm front and cold front' (2-3 days ago) possibility.
Several Tornado warnings and some occurrences are in place as I type 

BE ADVISED: As these storms work north toward Brevard conditions could become more favorable for ''rotation' depending on exactly what happens with Andrea to the west (time now is 7:15AM),  be on the alert in Brevard beginning 7:30AM through the following hour at least in general and then further north 

SPC is watching this area so far today as of early morning, but this might be changed in their next update (SPC - Storm Prediction Center located in Norman, OK)

As far as these posts go, it is the red areas so far that might pose
 a large tornado threat LATER TODAY
beginning around 12-1pm (and esp. toward 2pm) . But this will not be continuous storm after storm. There might be a large break in the action as noted by this recent image.

TODAY: No need to go into details today, as the posts of the past few days have pretty much zoned in on the generalities of the upcoming situation which is now in place; additionally, TV and media through the Weather Service have emoted the same message far and wide, lest one be left in the dark. It was only a matter of time.

Andrea, as it is, is expected to take the general course of the GFS proposed several several days ago which comes close to the ECMWF and the Canadian as well. Andrea might increase in strength just a bit then expand and weaken at the surface after exiting the Loop Current region, but that expansion would only serve to increase the tornado potential, especially over the East half of the state.  An upper level negatively tilted trough will eventually catch hold of the storm, but that negatively tilted trough across the peninsula will only aid in increasing wind shear and helicity, mostly over the North Half of the state as the situation evolves.

In that regard, warnings and another tornado watch could be issued by later this morning to extend toward the sunset hours for a portion of the state. For now, those red boxes seem only to me in regard to latest guidance to be the most likely candidate areas, although a watch box would likely  if issued, be much larger. Heaviest rainfall TOTALS for this even appear will be along and north of I4 toward NE Florida but brief and heavy amounts could occur in the heavier storm cells.

Note, as mid-level winds to the lower levels  increase, any storm could produce very strong wind gusts and temporarily strong straight line winds over 50mph (but as always, refer to official sources).

BEYOND: Not much change in reasoning until Andrea clears the deck. Chances of thunder and much better sky conditions tomorrow and through the weekend with a chance of thunderstorms by earlier in the afternoons. By MOnday, it appears most storm activity will be sea breeze convergence related, inland areas.

Potential for Rotating Storms Remains - Monitor Bulletins, TV Stations, Weather Radio

Note the red "I" indicating the surface circulation of Invest 91L. The red area indicating best combination of convergence and divergence should move tandem with the center as it llifts to the NNE-NE through Thursday and approaches the Panhandle or Big Bend (depending on the chosen model) 

TODAY: Thinking is not much different than yesterday although there could be a broader scattering of showers and some thunder away from clouded up areas. Showers are already underway as this is being typed. Today's post will not focus on the current weather so much as the 'potential' for heavy rainfall mainly near I-4 and north as well as 'tornadic' or 'rotating storms' capable of producing wind gusts to 60mph on Thursday. But, this still remains questionable.

TONIGHT/THURSDAY: There are two general camps model guidance is hedging on regarding what happens in the Gulf, for what happens there will determine what is to happen over Florida and where it does what.

One camp has the low moving more toward the north. The latest HRRR model which is High Resolution and short term shows that to be the case as does  the NAM model. If this does occur, the chances of severe like weather in any form, including flood potential in vulnerable areas goes to nearly zero. 

The latest HRRR seems in fact to be developing something akin to a Tropical Storm with a well formed eye in the next 18 hours. With that said, this post will focus on the other scenario indicated by the Canadian Model (in regard to direction), the ECMWF Operational and Ensemble Suite combined with the latest morning GFS which is just being made available on the internet as this is being typed. So far, the latest GFS in the ' general details' agrees with the Euro to not develop the system much more but rather keeping the system rather 'open' in the mid-upper levels which seems more rational given how right-handed the storm is. The center is in fact shown to be in rather dry air at this time.  Thus, the track (if this continues to be the case) of the surface low is not nearly as important as noted previously as the weather that will or could occur to the 'east through nearly south of the low center' as it tracks according to those models toward the Big Bend region north of Cedar Key.

TONIGHT: Per the GFS, some 'inclement weather' could begin to impact the SW Florida coast as soon as post sunset today. Latest radar is showing some rather strong storm cells well SW of this region as I write only making slow progress. The biggest issue occurs well after midnight and then more so after 10AM Thursday morning as the mid-level low 'expands' and sends a mid-level like 'warm front' northward coincidental with a low-level jet like feature. The end result of that boundary is to :

1.  keep S-SE surface winds intermingled with increasing midlevel SSW-W winds of up to 6o kts not far overhead, turning with height; as well as to .....

2. draw unstable air northward toward Central Florida. Guidance continues to indicate the heaviest rainfall along and near of I4 but there is very little convective instability in that area. Thus, a low Cape/High Shear environment exists there per this model run for low topped supercells as well.

The secondary additive 'factor' to be watching is along and near the  Central Dividing Line running in this case from Near Tampa Bay to Cape Canaveral/Port St. John where the GFS (Global Forecast System) shows decent instability creeping northward after sunrise making it to about that line. That is, if in fact the instability performs as shown.

This would :
1.set up a local mesoscale dynamic boundary overlaid by increasing directional wind shear  as well as speed shear from 2000-15,000 overtop that unstable air mass at the lower levels;

2. Thus, resulting in Bulk Shear values exceeding at times 50kts in a narrow corridor across a part of Central and high very high helicity values, both of which are conducive for rotating thunderstorms. 

That is, if the latest GFS stands correct.... Noting that these values are in INCREASE since the previous post, thus upping the ante on the potential tornado threat from mini-supercells if not full blown ones at the rate that model is going which looks a bit far fetched, but embedded as well in cloud coverage. 

This is a worst case scenario though, at least so far. It is worth nothing that storm activity will likely be embedded in perhaps light rain and extensive cloud coverage, and thus will not be easily discernible to see from a distance with the naked eye. Man your TV radar stations.

Again, all hinges on what the low in the Gulf eventually does. Interestingly, another player in the puzzles is high pressure aloft to form east of Florida which increases the 500mb pressure gradient. That is a new player likely responsible for the increase in bulk shear through all the midlevels of the atmosphere since the previous model runs, and is suspect.

WIth bulk shear from 2000 ft THROUGH 10,000ft like this image indication , you
"Don't  Mess Around with Big Bad LeRoy Brown"
Values such as these are shown to develop shortly after sunrise and spread across the state from SW to NE perfectly timed with 2pm peaking heating hours on Thursday by which time instability will have crept as far north as the Central Dividing Line.Again, will any of 'this' actually ever evolve as the model shows? It's not worth the risk to not mention at this point.

The Red and Blue wind barbs indicate the change in wind directions at two various levels. With barbs like that over the state (note, for example, much weaker winds well out in the Atlantic in the image above as opposed to 45 kts in one direction and 35 to 45kt in another direction overlaid across Central Florida. The "Red Box" would indicate a Tornado Potential Zone for the entire period of overnight tonight through sunset or late afternoon Thursday. Beginning to the SW Coast and Spreading East and North with time

This post will not go into other values such as horizontally spiralling helicity values, but will leave a mention that the National Weather Offices are fairly 'impressed".

TAMPA'S OFFICE: "OVERNIGHT...BOTH THE GFS AND ECMWF CONTINUE BUILDING WIND SHEAR AS THE LOW LEVEL JET BEGINS TO BLANKET THE AREA WITH 0-1 KM HELICITY OF 100 TO NEARLY 500 M2/S2 FROM SOUTH TO NORTH BY 12Z THURSDAY. THE 06Z GFS FEATURES 0-1 KM BULK SHEAR VALUES OF 35-40 KTS AROUND THE TAMPA BAY AREA AT 12Z THURSDAY. THE EVOLUTION OF THE POTENTIAL EVENT WOULD CONTINUE NORTHWARD AND EASTWARD AS THE CENTER STARTS HEADING TOWARDS THE COAST OF THE BIG BEND OF FLORIDA. THIS EVENT WILL NEED TO CONTINUE BEING MONITORED AND SMALL CHANGES TO THE LOW TRACK AND HOW MUCH AVAILABLE INSTABILITY WILL BE AVAILABLE FOR CONVECTION.


MELBOURNE'S OFFICE: TONIGHT..".06Z GFS INDICATED THAT BANDS OF HEAVY RAIN MAY BEGIN TO AFFECT PORTIONS OF THE AREA LATE TONIGHT AS LOW LEVEL SOUTH TO SOUTHEAST WINDS INCREASE. MODEL GUIDANCE SUGGESTS THAT THE NORTH HALF WOULD BE MUST UNDER THE GUN FOR HEAVY RAIN...BUT AM CONCERNED THAT A CONVERGENCE BAND COULD ALSO SET UP NEAR THE SOUTH COAST. THEREFORE WILL ISSUE A FLOOD WATCH BEGINNING LATE TONIGHT FOR ALL COUNTIES.

A PSEUDO-WARM FRONT WILL LIFT NORTHWARD INTO CENTRAL FL
INCREASING THE LOW LEVEL SHEAR WHICH SHOULD ALSO PRESENT A THREAT
FOR ISOLATED TORNADOES. PEOPLE IN EAST CENTRAL FLORIDA SHOULD MONITOR THIS DEVELOPING WEATHER SITUATION TONIGHT THROUGH THURSDAY.

INDEED...MODEL GUIDANCE INDICATES VERY HIGH HELICITY VALUES BTWN 12Z THU AND 00Z FRI (300-600 M^2/S^2) ALONG WITH RESPECTABLE CAPE VALUES (BTWN 600-900 J/KG N OF I-4...BETWN 1600-1900 J/KG ALONG THE TREASURE COAST). A SOLID 45-50KT S/SE FLOW THRU THE H85-H70 LYR BCMG S/SW BTWN 18Z THU AND 00Z FRI IS A NOTEWORTHY INDICATOR AS WELL. FL RESIDENTS AND VISITORS ARE URGED TO REMAIN UPDATED WITH THIS DEVELOPG WX SITUATION. "

===========================================

Do note the above discussion was written for the 06z model. Since that time, 

it appears the values noted have increased on the GFS run just now coming 

out.

BEYOND: As the low 'supposedly lifts up the east sea board it will leave a 

boundary behind with plentiful moisture making for a continued chance of 

afternoon thunderstorms, esp. near the East coast and warmer temperatures 

as high clouds and their coverage will be out of the picture through the

weekend. By Monday  the ridge axis lifts north to where I appears most activity will be over the interior, at least for a day or so.

If the El Reno, Oklahoma Tornado Had Hit East Central Florida

The areas shown above are VERY generalized

http://www.youtube.com/watch?v=DjGUEWZ26_w

MAXIMUM INTENSITY

• The tornado struck mostly rural areas of Canadian County, leading to difficulty establishing

maximum intensity.

• Initial estimate of EF3 was based on damage to several structures, but the inferred tornado

intensity was an underestimate of tornado strength because of the scarcity of damage indicators

and very small regions of extreme winds.

• However, two high-resolution mobile radars acquired high detail datasets of the tornado.

• The University of Oklahoma's RaXPol, a rapid-scan, Polari metric, mobile Doppler radar, measured

winds greater than 295 mph at several times and locations within 500 feet of the ground along the

south side of sub vortices on the south side of the tornado.

• These extreme velocities occurred several times in the RaXPol data.

• Extreme winds associated with small, rapidly-translating sub vortices within the larger tornadic

circulation.

• These intense sub vortices remained over open fields and did not directly affect structures.

• The two most intense sub vortices with the highest velocities occurred north and east of the

intersection of 10th and Radio Road approximately 3 miles SSE of El Reno.

• The observation of winds well above the EF4/EF5 boundary from two independent rapid-scan

mobile radars lends confidence to the observed winds.

• Known damage indicators were compared to RaXPol velocity measurements; good agreement was

found between EF-scale rating and velocities above.

THESE TWO IMAGES ARE VERY VERY GENERALIZED TO GET THE IDEA. ONE SHOWS THE AREA SOUTH OF THE PINEDA CSWY (LEFT)

AND THE OTHER IN THE ORLANDO AREA (RIGHT) TO SHOW ENTIRE AREAS DIRECTLY IMPACTED WIDTH WISE BUT IN NO WAY LENGTH WISE

(WHICH BE IN GENERAL ABOUT 5 TIMES THE DISTANCE SHOWN ,THOUGH AGAIN NOTE THE TORNADO WENT FROM UNDER A MILE
WIDE AS A SMALL VORTEX TO IT'S MAX WIDTH RELATIVELY QUICKLY (AT WHICH TIME IT WAS OVER MAINLY OPEN COUNTRY).

FAST MOVING SUB-VORTICES WHICH MAY HAVE RACED AROUND THE CENTER MIGHT HAVE BEEN RACING AROUND AT UP TO 180 MPH

FORWARD SPEED

"TORNADO ON THE GROUND!"

FOR 40 MINUTES JUST AFTER PEAK OF RUSH HOURS TRAFFIC  (BUT GOOD NEWS. AN EF5 TORNADO HAS NEVER BEEN RECORDED TO HAVE OCCURRED IN FLORIDA)

(MAP DOES NOT INCLUDE THE "KISSIMMEE OUTBREAK" WHICH WAS THE WORST IN EAST CENTRAL FLORIDA HISTORY 1998)

  

Good Chance of Thunder Again Today With Heavy Rainfall / Frequent Lightning /Funnels?

Linear Arcus Cloud along leading edge of thunderstorm -
Banana River, Cape Canaveral , FL - Sunday Evening

TODAY: Tsunami of atmospheric moisture appears will be moving in from the SW portion of the state early on to reach the East Central Coast mainly along and  south of I-4 by mid-afternoon. Chances are this will not be fully realized until after 4pm near the immediate coast east of I-95. Regardless, despiste SW flow aloft, a sea breeze should be able to set up by around noon time if not a bit earlier but not make much inland penetration. The heaviest activity as usual would occur over a larger area as the west coast sea breeze presses eastward to meet the east coast sea breeze. In particular, if a more side shore component type sea breeze sets up the area near Cape Canaveral-Port St. John - Titusville - N. Merritt Island could get 'interesting'.

With that said and noted, and if that is what actually does end up being the cast, the heaviest rainfall would occur along and east of I-95 mainly from southern Volusia County southward to Palm Beach County area. Wouldn't be surprised with such a fresh influx of Deep Atmospheric Moisture exceeding 2.0" (perhaps as high as Precipitable Water of 2.3") that some 'funnel cloud like looking' clouds shapes might be noted today  although there might actually end up being  a  waterspout threat later today along the river ways or out over the ocean, but the biggest danger would be the lightning. Rainfall could persist near the east coast (mainly) until near midnight in some locations if all unfolds as suspected this early hour of the day.

Invest 91L shown near the Yucatan with weak inverted mid-level trough extending toward Florida. Watching that purple area for some bigger rainfall totals and maybe some 'water spoutage action?". 

TUESDAY: This day looks very iffy regarding thunderstorms coverage. High precipitable water values will be in place but am wondering if cloud coverage and/or weak & chaotic wind patterns won't make it a bit difficult at this point to pin-point when and/or where rain will actually occur. Broad brushing it for now, same goes for Wednesday.

THURSDAY: Still not much change in guidance for Thursday being the most active day, at least as far as the 8pm model runs went; however, the 2AM GFS really holds off on any significant weather to occur any day, with whatever comes out of the Gulf never really making it to Florida at all. But, based on very very close model consensus (The GFS and the ECMWF) with both showing a mid-level vorticity max to rotate around a larger low pressure area and then in advance of it from Thursday morning and across South Central to Central Florida during the day and into the early evening, a brief 'severe weather window of opportunity' presents itself. This is still a number of days away to be considered too seriously though. Regardless, if this indeed does end up being the case, it appears a tornado watch would be warranted with Hodographs and Soundings Looking like this once again:

NOTE that LARGE LOOP in the lower left hand corner with the location for that shown on the right. That spells major rotating thunderstorm (at least), a tornado producing type. On the other hand, this is all contingent on whether or not that vorticity max alluded to in the above paragraph is actually 'For Real".

BEYOND: With all that has been said, the extended into Friday and beyond is contingent upon what is to occur (or not occur) on the Thursday time frame. If the last GFS is correct in holding back any type of 'system' crossing the state (noting the ECMWF is still quite adamant of a 'center' crossing near I-4 to just north of it ...) there will still remain the chance of afternoon activity and greater cloud coverage with daytime heating into at least Saturday if not longer, with a 'settling in' of a more summer like sea breeze pattern evolving, favoring the interior and east side of the state. Another trough again is forecast to suppress the Atlantic High pressure ridge axis across the state to somewhere across the Lake Okeechobee area making for a SW-W steering currents aloft for late day east coast storms from isolated to scattered.

It is with deepest regards that HSD extends condolences to 3 highly acclaimed Storm Study Entrepreneurs that passed away during the recent unusual tornadic event near Oklahoma City a few days ago. 

Pattern Change! - "Pandora's Box of Adverse Weather Watches" Later in the Week?

PATTERN CHANGE COMMENCED LATE SATURDAY OVER MUCH OF FLORIDA. See notes above.

TODAY: The last post was Saturday a week ago which referenced the chance for a prolonged period of easterly winds, after a severe thunderstorm warning on the prior Thursday and then a rocket launch on Friday. On shore winds with periods of showers (mainly South Central and South Florida and toward the west side of the state (most notably yesterday) was the rule for several days. That pattern began to break down late Saturday and continues to break down as this is being typed. Note the light wind this morning.

High pressure to the east of the state is retreating to the east as a frontal boundary (which resulted in the Oklahoma City tornado traffic fiasco the other day, see images at end of post) progresses east but will never clear Florida.  Meanwhile, a broad and somewhat disorganized area of low pressure is to organize slowly over the next 48 hours in the Bay of Campeche with somewhat of a mid-level 'like' inverted trough to become more developed across the Central Florida region as noted above heading into Wednesday. (surface features will be a bit different). Now that we are caught up to the current time:

SUNDAY-TUESDAY: The short of all of this for today through Tuesday:  Better chances of thunderstorms as opposed to rain showers from early-mid afternoon, possibly lingering to well after dark as they decay after sunset. Steering currents today are already on the shift from west to east but very light and will unlikely be able to combat the east coast sea breeze, at least until early evening. Increasing moisture from the South could result in a number of showers and thunderstorms (mainly away from the immediate coast) although thunder might be audible from there. More likely some showers might be able to go up along the east coast sea breeze as it develops toward noon and onward making slow westward progress before meeting up with similar conditions from the west by mid-late afternoon over the interior. With a slow eastward push aloft, some of this activity might be able to make it to the immediate east coast just about anywhere along the Florida east coast by evening (or earlier toward South Florida) as the east coast sea breeze retreats back to the east coast.  Do note  that invariably each day will vary from one to the next so the "Day by Day" forecast blog post rule will apply through the week. Severe storms are not expected although a Special Weather Statement or two might become necessary for some stronger wind gusts and possibly some local flood statements due to slow storm motion and accumulating resultant rainfall.  

WEDNESDAY-FRIDAY: This is the most potentially volatile period as it stands this morning for a variety of reason which will only be briefly spelled out this morning due to the 'yet to develop' situation that has been captured by virtually all the forecast models in some form or another.

For today, I'm discounting the Canadian Model which shows a strong tropical storm moving into the Florida Big Bend later in the week.

Although, the 2AM (EDT) GFS is showing a Sub-tropical depression like low pressure area moving across the I-4 (which will be noted in imagery below).  The overall consensus though is for not one but two main areas of low pressure to cross the state from Central to North Central Florida from sometime overnight Wednesday toward Friday (with possibly smaller imbedded impulses as well). Timing might never be pegged down exactly but we'll spell out a few things that have been fairly consistent, then from that point we will be able to see how well our forecast models end up verifying in the coming days ahead.
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1. A sub-tropical like low or series of lows (Perhaps a depression) will eject ENE-NE from near the NW tip of the Yucatan Peninsula toward Florida, highlighted and finalized by a more organized one at which point the 'show will be over'. It is the earlier stages of development of that final 'low' that is of most concern regarding a window of opportunity for brief tornadic/mini-supercell 'spin ups'. So far that window has been showing up from SW-W Florida and extending eastward and NE around the Wednesday-Wednesday night time frame into Thursday. Images below :

PRELIMINARY HEADS UP JUST IN CASE: The red box would be perhaps a tornado watch area with Flood watches as well being hoisted on the late Wednesday time frame. The lower left image is a depiction of the curvature of winds with height. Large looping hodographs would favor the tornado potential  which at this point is indicated by the red box above with other notes. Although that hodograph is not 'large' it is looped and it does get more 'interesting' toward a portion of South Central to the Beach line zone later in the period.

2. The more interesting thing that might be a fly-in-the-ointment is just exactly what if anything might develop as the upper level energy cross the Loop Current in the Eastern Gulf. The latest GFS is actually forming a weakly closed sub-tropical like Low pressure with winds of Tropical Depression to minimal Storm strength  Regardless of whether the system is named or not appears so far to be irrelevant unless we are in for a big surprise the next 72 hours. The fact remains that the GFS model has been showing this 'tornado' or strong wind gusts in mini-supercells (rotating thunderstorms) for quite a few days in a row now.

From the period of Early Thursday through Friday a "Pandora's Surprise Cache-Cash Award of Watch Boxes" might be in the making for accumulating rainfall of up to (dare we say 8 plus inches?) toward I-4? Do note, the Climate Prediction Center was highlighting South Florida just the other day for highest rainfall, but it contradicted another link on the same page that was showing further north (from what I could tell). The red area is of 'Overall " biggest interest as of this Sunday Morning for   tornado potential although all of the state mainly south of  I-10 will be in the cards of something interesting at varying times from late Wednesday into Early Friday.

3. To up the ante on a storm track which is shown by the black line above along that dashed line shown in the first image, the latest ECMWF model is finally available on this computer as of 4:40 AM Sunday morning. Noting that although this model is amped as the most reliable time and time again, it initially was taking a low into Louisiana  whereas the GFS has never once implied such a track.

LATEST ECMWF GUIDANCE SHOWS TWO VORTICITY CENTERS (with another lingering in the Gulf)

The greatest tornado threat (if there is to be one) would NOT be under those lows but South and ahead of them..particularly as the first one moves in. The GFS and even the ECMWF have been 'implying' somewhat of warm front/cold front trough like system associated with the first low. It is along and preceding a pseudo-like warm front lifts northward from the Keys toward I-4 into Thursday-late Thursday  time frame so far that is most interest regarding that feature (which was reflected in the early image showing the hodograph).
So far, the biggest risk area begins toward SW Florida/Keys which lifts NE'tward to East Central Florida slowly with time.


4. GFS rainfall totals directly associated with those little 'vorticity maxes' have been tracking rainfall over a 24-48 hour time from of up to 8" (at least) for quite some time now generally along I-4 toward North Brevard County although there was a time when the track was across South Florida. Will this all change once again?  Quite possibly, although the time is drawing nigh and not once has the ECMWF tracked a disturbance across South Florida.

BEYOND: The system should be clipping the outer Carolinas just in time for another front and upper level trough which was shown in the very first image in this post to be pressing east. This will continue to keep the Atlantic High Pressure ridge axis suppressed across South to South Central Florida placing the state in a late afternoon thunderstorm / "Welcome Summer?"  Wet Regime like pattern up through the 12th of June which is a bit early, favoring the east side of the state for late afternoon thunderstorm activity.  

OTHERWISE: Discussions from a wide variety of forecast outlets are looking for an active tropical season. I'm watching the Northern Gulf and Florida particularly this year, not that it matters..but this area is long over-due climatologically speaking, especially South Florida (Miami/Dade) area for a "Big Named Storm".

TWITTER "TWEETS" regarding the other day in the Oklahoma City area  as the "High Speed Dirt"  flew not only along the ground but across the wires and the wireless.

Breezy This Afternoon, Drier and Mild Especially Beach Side

According to the NWS a wind surge came in toward Daytona earlier, this surge might reach the beaches of Brevard before noon time and then 'mix out'. Otherwise, very nice weather throughout the weekend and a bit cooler

 NOTE: The GFS (Global Forecast System Numerical Weather Forecasting model) is again bringing back a tropical system toward Florida the first week of June. HOwever, it has been doing this for nearly a week now only off and on in an inconsistent fashion, at this point it holds little to zero credibility although the timing is impeccable.

Delta Launch Last Night As Viewed From Cape Canaveral 

This Severe Warned Storm as it appeared looking west on the 528 West of Canaveral and East of Merritt Island, Florida on Thursday

The Storm Started to take on a
"Flying Eagle" Appearance