Chance of Strong/Severe Storms Today

Fairly Close model consensus so far this mid-morning with surface 'now' data indicating that a weak surface low could form for reasons described below. East coast sea breeze convergence along or even east of I-95 could, if current thinking
holds fast, result in rotation in a few storms from Saint Augustine
to Central Brevard  

TODAY: Tricky forecast, but waste not want not. So wasting no time to get this post out as a precautionary measure.  Some "scrappy Cu" (cumulus clouds) already forming in thinning early day mid-level clouds over Central and North Florida as sun beams in.  Jet stream level winds across the South Half of the state with agreement that Central Florida will be under the right entrance region  of those winds. Additionally, latest guidance in two models shows a  streak of 20,000 ft. winds at 500 mb (millibars)   streaking right across Central Florida later this afternoon right under the divergent winds aloft . Highest convective instability is forecast to exist from Lake Okeechobee and North, due the result of late night through early morning  rain activity further south where jet stream cirrus clouds continue to run over that Southward Area now and as it looks, the remainder of the day. Meanwhile, surface boundary to sink into North Central today, with latest surface and low level streamline analysis indicating convergence along that boundary increasing during the day, especially along any sea breeze front resulting in stronger upward vertical velocities.

With those factors in mind 1) Divergence aloft 2) strong 500mb wind core 3) instability and finally, the big question mark, 4) an east coast sea breeze which seems most likely north of St. Lucie County, and 5) coldest temperatures aloft from 10000 ft up are from Brevard and North. South Florida might be contending with outflow backlash from early day activity, but things could change down there quickly, as often seems to be the case. Regardless, without a doubt the region further north, as it stands now at least, holds the better chance of severe weather today . So with those factors in mind:

Questionable activity South Florida. More than likely, this region will see some storms today, but all things considered further north those factors seem to pale in comparison until after 7pm tonight. By that time certainly it could all be a different story. Otherwise, North bound we go where from this image alone one can see the skies have cleared with no high clouds coming in from the west off the Gulf of Mexico. 

ADDITIVE FACTOR: Low to mid level helicity values along the coast, especially from Brevard and North are shown to be the most consistent in guidance, with a concerning higher value running from near Southern Volusia toward Cocoa Beach, and again further north toward Ormond Beach give or take 50 miles north/south. Another factor is that latest guidance is showing stronger downdraft CAPE values encroaching in on the entire west side of the state from the Gulf. Downdraft CAPE tends to limit overall coverage, but that which can form , that is to say, can work against the downdraft cape into updrafts, can result in storms that rapidly build vertically, resulting in hail and/or strong downburst winds. Thus the area in red as well. Such downdraft CAPE would also, if it is true to form as a mere 'mortal model' can show, would INHIBIT activity over South Florida already covered in High Clouds.However, guidance is showing rainfall down that way, the type for lightning production. Best best at this point down there would be from Port Charlotte and South inland toward Lake Okeechobee and the Everglades for any potential strong storms,. 

THUS: The purple area would be considered for this post to be a zone to watch for rotating thunderstorms and maybe even a brief waterspout or tornado, especially South of St. Augustine and North of Vero Beach, with a possible highlight north 1/2 of Brevard County east of I-95 closest to the boundary, convergence, instability, divergence, and 500mb wind core (IF IT IN FACT WILL EXIST). Any activity especially after 4:30Pm near the coast (if it manifests) is worth monitoring today, especially for deviant right or left moving activity. Storms or showers could continue in isolated fashion after 9pm. toward midnight.

FRIDAY: With today's "Potential Soap Opera Drama" on the line, tomorrow per the latest NAM model shows yet more, thus today / tonight could fold with... "...To Be Continued".  Today's boundary gets 'locked up' in the quick upper level winds and has a hard time dropping, at least permanently, much further south than Southern Brevard, if even that. Net result is the same sort of set up on Friday only this time from Brevard County and South toward Palm Beach County. See no reason why high clouds again might not be a factor further south, toward Dade County at least. Otherwise, might need to watch mostly inland toward West Central and SW Florida, as winds gain more of an east ward yet light component in higher levels of the atmosphere. 


Beyond Friday is a big TBD, but based on what I'm seeing the previous post looks valid yet still, namely early day activity east side translating toward the interior mid-late afternoon, with activity attempting to migrate back east yet again toward or after sunset through Tuesday. 

Today's Forecast Picture Says But One Word

CLOUDY

Today: One look outside looks not much different than it does from outer space, other than from there the clouds are white; how interesting of a day that would be to see from the ground and be looking up, nothing but a cloudy white as opposed to grey. The trough shown in purple at the surface and into the upper levels makes slow leeway east and south during the next 48 hours. For today, there are some Florida Oranges drawn in to indicate tangerine dreams thunder at best almost anywhere, but two locations seem to have a best shot though not shown here. One being Dead Central interior very late today toward the east coast southward toward Palm Beach County. The other area is the NE Quadrant of the State as far south as Ormond Beach where thunder has already occurred. There is only two storms state wide even at 220pm in the afternoon, and they are on opposite sides of the state and barely moving. Steering remains weak as does heating due to the cloud cover, and with little sign of a surface boundary and so far no apparent easst coast sea breeze (or barely) forcing should be fairly weak and the surface if there is any boundary interactions at all.


THURSDAY/FRIDAY: Possibly a better chances of storms or rain showers North Central and south of there almost any time, but Thursday and/or Friday might be able to yield a strong storm risk in there. All contingent upon the amount of early morning and overnight Gulf Stream activity which shreds high level clouds across the state when or if they do occur.  The GFS is showing reduced high level cloudiness (moisture) overnight later tonight but that could easily change if more storms generate well to the west of the state. If the day dawns sunny, the chance of rain is better.


BEYOND: Really no change to forecast reasoning from yesterday or days before. Boundary will have worked Southward into South Central or South Florida on Saturday with a deeper easterly (but rather light) flow. This could result in early morning to overnight showers close to the east coast progressing inland during the day. The GFS is consistent that this highly unusual May pattern (which is acting more like the middle to late summer minus the warmer surface temperature) could continue to months end.   That is a big stretch, but the gist is not expecting any astounding or earth shattering changes in the overall pattern from Friday and beyond, although that shalt change in the days ahead.

"Chance?" of Some Strong Thunderstorms Today and Numerous Showers

Image depicts a fairly deep east coast sea breeze could be forming as of 2pm. Storms
over North East Florida seem to have been triggered by higher low level instability combined with a bubble of upper level divergence aloft resulting in an upward vacuum early this afternoon. Otherwise, it appears all of South Florida will begin to 'fire up' in the next 2 hours, if all holds true to form per model guidance due to greater instability in this area as well 

TODAY: A frontal boundary that has been meandering toward the western Florida Panhandle seems to be 'fizzling' a bit, in regard to how well defined it was 2 days ago. Wind fields at all levels below 20,000 ft are 10kts or less, but much stronger higher up. Latest LDIS and guidance shows (and has been showing all day so far) a 'donut hole' of greater stability across Central due to early high level cloudiness that is only now beginning to clear on out. This area remains a bit of "??" this afternoon in regard to 'will storms truly be able to fire there?". It appears that any activity from North Florida as well as South Florida could send outflows into that region, so that storms there will run later in the day after peak heating. 


So, with a bit of hesitation, but owing solely on model guidance consistency (other than one of them), willing to hedge in on the storms gathering momentum in number in the next hour or so (currently it is just after 2:25pm) over North and South Florida , but with the strongest of storms forming after 4:30-5:oopm in the 'questionnable zone' of Central and South Central toward Lake Okeechobee southward into Palm Beach County.  I see why guidance is heding on the East Central Area being 'out' today for storms based on the morning KSC sounding. It's a matter of whether or not it was a small or large area that showed unfavorable storms as well as whether or not those conditions remain there and all of central all day long, which is a big unknown. 


The east coast sea breeze at this hour does not appear to be yet past I-95, and the west coast one has begun as of the last hour per visible satellite image animations. Things can change quickly though, as it has done in the past, with the east coast breeze suddenly gaining momentum after 4pm and pushing well inland.


Otherwise, temperatures aloft are cold enough to result in storms with small hail, and a quick down burst or even microburst of strong winds central, where there is a low level dry layer. ON THE OTHER HAND, that drier layer, should it remain (and at this hour it is shown in short term LDIS, Local Data Integration System as well as the RAP (the new Rapid Refresh model) guidance as a higher Level of Free Convection (LFC) unfavorable for storm formation. 


There are times that activity simply cannot manifest in such an environment until after dark or not at all. Giving the models the benefit of the doubt though, should those factors improve, the best chance of those stronger storms will be along the Sea Breeze merger then back eastward in subsequent outflow / post sea breeze environments toward I95 if not US1 from Brevard County Southward.


Activity it appears will be sapped out early on this evening by 8-9pm, wherever that may happen to be...likely South Central or South Florida.

Red is where some of the higher chance of a pulse strong storm could occur, not to discount anywhere else within the orange zone however.  Again, The region across all of East Central remains just a bit in question, and therefore remains the 'wild card' out, or Ace of Spades for the Strong Storms winner's circle. 

TUESDAY/FRIDAY: Appears that within the time frame of Thursday or Friday the frontal boundary (not shown) remains will work toward Central and become drawn out and possibly dissolve. Much depends on what happens toward the Yucatan Peninsula. 


Guidance has been hinting at low pressure forming in that area with an inverted trough forming northward from it, possibly enhanced by the unstable waters of the Loop Current of the eastern Gulf. Should the frontal boundary latch on to that boundary further southward progression of the front should cease, and equally allow moisture from the Caribbean to converge along it resulting in over night toward early day showers and thunder working westward into the interior and west side later in the day. Much to be resolved in those regards.

Otherwise, although it appears this could be a day by day deal to determine if or if not there is a decent shot at storms each day, at time that appears to be the case. The main factors that would negate such chances would be higher level clouds early in the day which would prevent low level instability to mount up for storm developments. On the otherhand, should a scenario as just described formulate, rain chances will remain in the cards for folks somewhere/sometime well into next week. Much depends on the strength of the front and how far south it penetrates...in other words, who knows.

Surface Boundary could be in this area by Friday with mid level moisture being drawn northward

 

Strong/Severe Storms Possible ..OR....

Red where possible "hot zone" storms could occur today from WNW of Ft. Pierce to the Coast and South into Broward County mainly near and East of Lake Okeechobee toward Ft. Lauderdale 

Frontal boundary, very shallow has reached South Central and dissipated.  Mid-Level trough is still to drop south this afternoon. Although there is just enough instability for showers as far north as the Cape, believe any showers to from later today will be along that mid-level trough toward Lake County, if even that.


Otherwise, the region where the boundary at the surface has waned out , is where it got caught up in stacked westerlies, increasing with height. The only down side to the areas shown is this region "could" be on the descending side of an upper level jet streak forecast to cross Central, although model guidance so far do not indicate this to be the case in the precipitation fields. Believe at this point most of Dade and just maybe Southern Broward might eke out on the storms due to forecast warming in the mid-levels, but should a storm punch through that layer they could go gang busters.


Given the forecast vertical helicity, and approaching mid-level lift ahead of the trough to drop through Central, storms could be strong to severe, although 500mb temperatures are not crazy bonker nuts cold, they are sufficient. 


***CAVEAT:**** Due to the lack of any low level boundaries, no forecast triggers in the vorticity fields, and if the RAP and SPC MesoAnalysis guidance is correct, the area in question could dry up in the mid levels to quickly after 330pm, which would discount this chance altogether to very little activity at all. Close monitoring thus will be necessary to either confirm either/or/ situation beyond that time frame. In the meanwhile, certainly some storms could manifest, but it is always possible there will not be ample moisture in place at or just after the time of  peak storm hours if those two  pieces of guidance are correct. Lapse rates that looked tremendous down that way earlier today are not as impressive per latest LDIS/RAP plot from the MLB NWS Office Website. Otherwise,


FRIDAY/SATURDAY: Pleasant and a bit cooler with no rains forecast for the most part except maybe some scant showers south Florida toward the SW Coast.


SUNDAY; Not a significant enough change in guidance to harp on what has already been written here the past two days. Mid level 'warm front' from the trough to pass down the state today lifts back north in response to mid-upper level low pressure across the north Gulf coast region. In doing so, moisture depth increases from south to north. This boundary at the mid-levels should be near Central by mid-afternoon Sunday, with showers reaching as far north as the Cape by near midnight or so Sunday night into Monday. GFS continues to expound a 'shift change', namely that the Brevard Coast area give or take a county could get very wet from post-Sunday Midnight through much of Monday, this will continue to be watched.


MONDAY-THURSDAY: Day by day give or take thunderstorm chances remain in guidance. The GFS and ECMWF appear to pull a cold front through on Thursday, and if so, that will be the end of this pattern on that day after sunset. So far, looks like an early afternoon start to showers and thunder ending after 8pm each evening Monday through Thursday. But, as the story ends, can't count the chickens until they've hatched, otherwise a forecast post for that time frame this far in advance could well be hard-boiled.

Strong Storms "Possible" East of I95 Later This Afternoon

Today's lead off image shows the upper level low over the Desert SW noted yesterday has dropped further south than expected. Meanwhile, in red is shown where the leading edge of upper level winds are estimated to be located earlier today, and in purple where that leading edge is expected to be by late afternoon moving in across the North 1/2 of the state.

TODAY: A front boundary will be entering the NW Panhandle by tonight. Meanwhile, SW flow is expected to increase toward sunset at the surface, but before that time (and here is the clincher of clinchers), the pressure gradient might not be strong enough to offset an east coast sea breeze which would end up pinned close to, if not east of, US 1.  for many locations along the entire east coast before the gradient increases toward sunset. 


Considering also, good surface heating toward the east coast and inland could provide for the added boost of a temperature (thermal) gradient from the cooler near shore waters to provide for a shallow sea breeze to form or upwind river breeze at least along the Brevard barrier islands. Further South, lake shadow wind effect could enhance storms either side (north of south) of the shadow into Palm Beach County or Martin/St Lucie County.  Further north toward JAX, there could also be a sea breeze south toward Northern Ormond Beach. So far, guidance is painting that the area just along or north of I-4 might become 'capped' due to a surge of warmer 850mb air temperatures, although this cannot ever be for certain. For now, the next graphic has made that 'assumption'. Also assumed is "the clincher of clinchers", a sea breeze or side shore component. If this does not form, chances are much lower of anything beyond some storms of generic quality except toward Lake Okeechobee and NE Florida.


Otherwise, although 500mb temperatures are not as cold as two days ago, that aren't far off from yesterday with still cool  at 700mbs. Good surface heating, instability (light -mdt), and some upper level energy to trigger showers and storms, especially after 4pm or so. Whether or not this will be of in the form of rain showers over the interior is difficult to pin point, but the best chance of thunder seems to be within 20 miles of the coast except toward NW Florida and the Panhandle as the front moves in. Conditions appear most favorable for any strong to marginal severe storms that might occur to be after 4:45pm today closest to the coast from the Cape and South due to local affects, and near Jax due to the proximity of the approaching frontal boundary, except near Palm Beach County will it looks like more of a low level wind field boundary happen-chance situation.  Showers and some thunder could continue in very isolated fashion anywhere along the east coast as late as 11pm in random fashion due to remnant out flow boundaries and residual convective instability.

This image shows a guesstimate for showers (green) to stronger storms (lavender) , although the area near JAX/St. Augustine and in the Panhandle could have easily been included for some 'purpling'. Stronger storms near the coast could contain small hail and wind gusts in excess of 50mph, especially after 4:30pm in a few spots under the premise a sea-breeze or side shore wind can form. 

THURSDAY: The Front will glide slowly south over night toward Dead Central by noon time Thursday. At this point, it is becoming just a bit flaky as to how far south and how fast the boundary will continue southward during the first half at least of the afternoon during peak heating. Winds aloft will be paralleling the front, and that factor combined with surfacing heating could slow it down. There is minute indications a weak surface low could try to form near Tampa Bay as well, which would further impede southward progress until after or near sunset. With this in mind, a pre-ump agreement (despite a few model runs showing otherwise) could call for showers or thunder to occur from the Cape south along the east coast on Thursday. Some could be strong as well with colder air aloft, but a seabreeze and thus lack of low level convergence would be a mitigating factor in that regard. Where ever the boundary is stalled or slowly moving will more than likely be the additive factor for stronger activity tomorrow, wherever that might happen to be.

Possible storms on Thursday if low develops. Otherwise, any storms will be relegated a bit further south toward Vero Beach. Some consistency indicates at least showers or something looking like showers no matter
what from the Cape and South

FRIDAY/SATURDAY: The boundary will remain toward far South Florida into the Straits Area but the 700mb trough never really clears Central. This COULD end up acting as a future source of storms by early Next Week, surprise surprise...otherwise, shallow depth easterlies could become a bit gusty on Saturday at 18-25mph, especially due the mid afternoon and into the evening.


 As such, showers could re-emerge toward SW Florida on either day, with possibly some light rains South Florida, but clouds seems to be the more prevalent mode south of the mid-level boundary except toward the SW Coast.


SUNDAY/ MONDAY: Upper low shown previously toward the SW U.S. never really clears the SE States but lingers across the Northern Gulf and parts of Florida as anticipated in yesterday's post. 


As noted before  (yesterday) another upper low fills the void from the Northern Plains states which drops SSE into the 'gap', re-enforcing that trough, while a surface low forms toward Coastal Louisiana and lifts another boundary northward, a part of the old surface front and mid-level boundary. Net affect, we could be seeing more thunderstorm chances as soon as overnight Sunday or early Monday near the East Coast south of the Cape, and much more widespread Monday afternoon and potentially for much of next week. After this point, it gets messier and messier in model inconsistency , at least in regard to climatology.

OVER GULF is what WAS the Desert SW Low. Note the trough
swinging southward from the Plain to fall into the same trough and re-enforce it.
Better YET! Look what is forecast then to approach from the west. Do note though,
this could all change by the next model run.

At this point, this is all a tough call. The  extended outlook'd 'pattern' is highly unusual for this time of year. The GFS and another model take it so far as to produce a tropical system over the western Caribbean which drifts north across Cuba in the next 12 days or so, which would be a first in QUITE a number of years this early in the season. If nothing more, the fact that a model (s) is even hinting at the possibility is worth noting at this stage.

More Showers/Thunder Today, Possibly Strong Thursday

Shower and thunder graphic. See note. Some thunder could move off shore South of Brevard toward Ft. Pierce and maybe West Palm Beach. Storms not expected to become strong/severe except maybe Toward Southern Palm Beach County in from the coast toward Ft  Lauderdale/Miami possibly. Temperatures at 500mb not as cold today, but whether or not that will have any bearing on storm strength is hard to say. 700mb remains cool one more day, but that could only mean storms will form quickly but not be strong. Highest instability starts off along the NE Quadrant of state by become state wide by early afternoon.  

TODAY: Another day of widespread showers and thunder possible. The only real difference today from yesterday is that 500mb temperatures might not be as cold as yesterday, although, morning sounding has shown no change from yesterday. Additionally, mixing ratios are not as favorable nor are the lifted condensation levels for solid low level storm bases. All models agree that warming is forecast by early afternoon nearly state wide except far SE Florida. The frontal boundary that worked toward South Central is to lift north and dissipate today, making for another day of outflow boundary, Lake Breeze Boundary, and Sea breeze interactions once again...making it quite difficult to pinpoint exactly where any particularly heavier activity will manifest, at least at this early hour of blog posting.


Here is the current upper level situation. NOTE the location of those 500mb winds today. This will be worth noting in latter portions of the post.

Winds aloft continue weak over the state. Steering will be toward the east again, but all depends on how quickly either the east and/or west coast sea breezes move inland as to how far rainfall will reach the east coast toward late day and early evening. So far, indications are that along the east coast it will begin around 12:30pm, upon which time showers and some thunder forms within the first hour or so afterward along or west of US1 to I-95. Thus, expect most areas on the east side or even 1/2 of state today will end up CLOUDY by late afternoon at a minimum. 

 Again, above is the upper level flow for today high high up there. See the low/trough to the West of Florida by Cali?  This low will gradually be moving east, but now guidance shows it never quite clears Florida through mid-month. Instead, NOTE THE NW CORNER of the image. Another Low is moving in.


The  low toward the NW U.S., now, is forecast to drop in behind the trail left by the first one, and carve a broad upper level trough along and east of the Mississippi in the next week to 10 days. There will be at least two more frontal boundaries to contend with during this process, the first being late Thursday as the one of today dissolves.


WEDNESDAY: Wednesday looks similar to today, but possibly a bit even warmer aloft in the mid-levels. Coverage difficult to ascertain, but expecting something similar to today, with little chance of severe or even strong storms as it stands now. Today will be a good test to see what does occur in the long run though. Never say never when it comes to boundary collisions is the key.


THURSDAY: As we can see, upper level trough and winds aloft now moving in, with a surface front (not shown) moving down the state. Convergence along that boundary, sea breezes, and cold air aloft could make for another day like Monday was only more active along the immediate East Coast. 

Compare image to the one above and note the winds that are stronger are now over the state. Colder aloft as well..but see where the low to the west remains? And see the other Still in the NW States. That one could slowly merge with the southern one carving out a broad path or trough of low pressure east of the Mississippi River going into Next Week. 

THURSDAY:  Possible stronger to severe storms on Thursday from Volusia and South along the east coast ahead of a frontal boundary.


FRIDAY/SUNDAY: Easterly winds manifest, breezy and dry, but with clouds and possible showers toward the Keys and Southern Dade, but pleasant otherwise. Front will be way south, but remain in the mid-levels. In a sense, so far, it could 're-manifest' by Late Sunday..moving back north..with rain south of Volusia along the coast in doing so. 


Monday/Tuesday time frame could be stormy or rainy along the east half of state, with the Latest GFS showing up to 2" of rain if not more in this area. That is a 'new one" though and too far out in time to hold fast on to.


BEYOND: Time will tell, the all in all though is that this pattern for this time of year is fairly rare from my recollections...as the amount of coverage reflects late June, with showers possible toward the third week at various times. 

Reflections of A Summer Like Pattern Through Thursday

Early afternoon severe thunderstorm warning along east coast sea breeze with little steering but cold air aloft, greater moisture in the atmosphere, better mixing ratios along the east coast, as well as better (stronger) atmospheric low level instability in the absence of down draft Convective Available potential energy and almost no inhibition allows early activity.


AT 122 PM EDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND   DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM WAS LOCATED NEAR DELTONA...AND MOVING SOUTHEAST AT 10 MPH. (the warning has since been cancelled).




TODAY: Frontal boundary has eked by Central Florida and will linger in the area for several days. Much of today will be quite similar to a summer like regime, with an east coast sea breeze manifesting early afternoon showers and storms along it  and sending out flows from said activity every which way, only to merge with the west coast sea breeze over the interior during late day and early evening.

Although storms could form along either sea breeze, the better chance will be along the east coast sea breeze as it progresses inland. Expect we could see yet stronger storms toward Lake County, then sending outflows back eastward late in the day. Other storms though interior Central are entirely possible.. It will all depend on how far inland each breeze progresses as to where the storngest storms are located/
Best regions look just about anywhere away from the coasts near and north of Lake Okeechobee, but showers and some thunder could occur even further south just in from the coasts. Skies becoming mostly cloudy east 1/2 of state by later today due to convective rainshower and storm debris drifting east and off the coast.

LATE TODAY: Expect that showers and some storms, <as noted there is already a severe warning>, will increase after 4pm. There is not a whole lot of cloud cover state wide as of 2pm (see below), and the day is still young. Temperatures aloft, especially down the east side of the state to be the coldest aloft, so would watch near and west of I -95 later today as inland mergers send outflows back and against the east coast sea breeze. Although low level instability is not super impressive at all, most of it seems to be coming off the Atlantic. Additionally, as opposed to yesterday, there is almost no down draft CAPE north of Dade County and across the state. Further south, there might be too much of that factor to allow even a rain shower because that factor acts to suppress activity unless updrafts are stronger than downdrafts...as was the case yesterday. Winds aloft are very weak, so storms will pulse up and down down quickly, spreading collapsing showers and cold air with them out in every direction. 


Late afternoon is when outflows collide after heating has built up all day...so would expect this could occur along and west of the east coast sea breeze wherever it happens to be located later today. Some activity could be stronger close to the decaying surface boundary/front across Central and might work eastward along it and offshore Brevard toward Martin County / Ft. Pierce after 7pm and into early evening.

THROUGH THURSDAY: Much of the same completely unforecast-able  and unusually early (!)summer like regime in regard to 'most likely' locations in advance beyond the day to day basis routine. Day by day analysis required, although Wednesday seems to be most favorable for much of the east coast to get a shot at rain and/or thunderstorms. 


Meanwhile, an upper level trough well to the west near the Desert SW region (see below) will be opening up and traversing across the Deep South. This system will eject upper level energy out in phases too difficult to peg down in timing. It will be a matter of a disturbance traversing over the state coincident with late afternoon peak heating combined with sea breeze/lake breeze/outflow boundary collisions that will be the strong/severe storm determinants today through Thursday. The boundary will sink further South by Friday morning through at least Saturday.

In General, this is the track of the low pressure upper level trough. It will take until early next week to pass near Florida if even at all. So far, this has been the trend in guidance from the GFS model (Global Forecast System). With that, we can see a down trend in activity on Friday through Saturday, but it could pick back up again by late Sunday or Monday. 

As noted   above captioned image, the frontal boundary near Central will eventually get shoved southward toward the keys area. But, as that upper trough approaches, moist and unstable air will get drawn back northward in advance of that trough. Thus, the frontal boundary to come back north by near the end of the weekend. resulting in another round of summer like weather with highs in the lower 90Fs, although cooler on Friday and Saturday along the east coast under the influence of a predominant easterly sea breeze those day.

Isolated Thunder East Central, Possible One Stronger Storm Toward Beaches

Isolated Thunder East Central Florida late afternoon into early Evening
Some showers in areas noted into the Everglades and around Lake Okeechobee.
Showers and some thunder near and north of I-10.

TODAY: Will leave this one fairly brief early this Sunday afternoon. Tables have about turned now for the onset of a new weather pattern which showed signs of its arrival late yesterday near Martin County. Expect that today, with precipitable water only around 1.2" (compared to near 1.85" - 2+" in the summer),  that any activity will be very isolated with 3 (at most) storms possible Central. Based on trends and guidance since early on, there is a chance that one sole storm could become strong, unusually so once migrating east of I-95 toward US1 and the beaches from near Mims south toward MLB after 6pm. This would only be possible in the presence of a late afternoon sea breeze remaining very close to east of I-95. As has been noted in the past, the sea breeze penetration can be very tricky at best any day, but especially so on days  when guidance does not show that one is supposed to even develop at all. For now, if it develops late and/or does develop but makes little inland penetration, a strong storm is possible eastern Brevard mainly. If it develops sooner, a strong storm could form toward Eastern Osceola County after 6pm.  Otherwise, sunny and bright with few clouds outside around any activity, especially after 5pm.


MONDAY/TUESDAY: As noted in the above image, more upper level  'wind' energy will be present in days to come, but not so much today.  There is not one day that a lot of Convective Available Potential  Energy (CAPE) is shown to pop up over the landmass, but moisture is expected to be increased by Monday, so more thunder and showers is possible on that day and Tuesday regardless of the fact the atmosphere is not all that unstable at the surface. The better factors could be colder air aloft, as will be the case today to some degree.


BEYOND: Thunder and shower chances should start to decrease from north to South, especially on Thursday with an end most areas by the weekend. It does not look like after a few day break in the activity the rain chances will be gone for good. An upper level system, slow to get here, will still be on the move from the west along the northern Gulf Coast; so that although we might see a break toward next weekend, there could still be a few days of more hectic weather to come heading toward mid-May.   

Pattern Changing - Slow and Steady For Central and South

Forecast Image for Monday where showers and thunder could occur. Weakened
frontal boundary across North Central by Afternoon

WEEKEND OUTLOOK: Diverging from forecast and SPC outlook today (showing thunder most areas), forewarned so could be off. Believe there will be very little rain over the weekend except toward perhaps North Volusia and North and along I-10 on Sunday, with thunder possible toward Gainesville, JAX, and north or toward DAB. Otherwise,
guidance is showing showers toward Orlando late day as a result of sea breeze convergence; however Convective Available Potential Energy for this time of year is barely suitable, and Lifted Indices are not much better than feeble. Can envision some showers at best and maybe only a good cloud deck materializing as inversion from high pressure that has been overhead weakens, with low topped showers as opposed to thunder. We are moving out of what has been a long established pattern while the 'Post big system' resulting in the tornado watch a while back slowly breaks down. Continued warm away from the beaches, reaching some 90Fs inland  with light winds, and an overnight onshore wind component maybe one more night well after dark, as has been the case for a few weeks now.

Toward Monday, boundary slides South, with another boundary approaching from the South Central Plains. Southern Branch jet will reside near the depicted Surface low and across the Northern to Central Gulf most of next week in various degrees

 MONDAY and BEYOND: The front shown across Central on Monday perhaps drops south a bit overnight but then lifts back north awaiting yet the next boundary. There has been some consistency now for 48 hours in varying degrees in GFS guidance, hence today's post. Showers and Thunder most likely near and north of Lake Okeechobee in days ahead next week, with some showers further south toward SE Florida. The main triggers would be the frontal boundaries resulting in convergence of sea breezes near it. Guidance is also showing that perhaps there will be no sea breeze at all, which would or could taper down the thunder chance; but, upper level temperatures are rather cool upstairs, combined with ample Convective Available Potential Energy CAPE (but not really excitingly so), and guidance rarely handles sea breezes in account of local data density. SPC already has a "See Text" for stronger storms on Monday near and north of the BeachLine (Magic Diving Line as referred to here time and time again)..Monday GFS does show a disturbance and good upward vertical velocities, but such depictions this far out  in time are perhaps not worth heeding conclusively as of this time today, but bears watching. If it verifies, strong storms Central on Monday. The only thing that has been constant is the rain chances, and thunder toward the east side of the state through Wednesday, with perhaps a day or two break here and there.


IN CLOSURE: Guidance has shown at some point or another this pattern will continue to varying degrees and locations for the remainder of the state into next weekend, so I expect we will hearing about some sort of rain chance on TV or other media outlets, time and place TBD.  It appears after this little dabble with frontal boundaries is over, although not shown, would be the next contender. HEAT...usually the hottest time of year near the East Coast is prior to onset of the Wet Season in Late May toward early to mid June.  ..but  this may not occur prior to a few days of possible strong storms here and there when all is said and done. Once any heat spell ensues, wet season follows, although there is no set rule I know of that says a heat spell has to occur at all. 3 years in a row there has been one though, lasting anywhere from 2 days to 5 days.

Complex Lower Latitude Weather Pattern to Persist Through Next Week

South to West Central Showers and Some Thunder, Most likely near Tampa Bay Later Today

TODAY: Latest satellite image shown above. Those high white clouds are shifting north and streaming off toward the east at the same time. Meanwhile, instability to build into South Central  toward lower North Central; however, the area north of the Beachline looks to remain 'capped off' for much activity other than a drip at most. Most likely area to get storms today along the west coast near Tampa under better sunshine as the east coast sea-breeze meets the near coast west coast sea breeze.


TOMORROW THROUGH TUESDAY: Same general pattern holds without going into details. It is possible that most rain will fall from Southern Dade and all of the Keys during this time frame. The wild card will be upstream of the Bahamas northward toward Palm Beach county where downstream fo easterlies helicity at low levels and shear across the islands could result in convergent bands moving ashore most anytime . Usually, these patterns fit a mold of 'most likely time it will rain within that zone', but exactly when that time will be is difficult to determine. Often though, it is near sunset or shortly thereafter until late morning.

BEYOND> Upper level and mid level lows seem to be trapped in sort of an eddy bubble, not unlike a twig caught between two rocks in a stream that rotates around in place. Current thinking, which has changed since yesterday, is for increasing rains state wide around Friday, with thunder possible. Will leave it at that for now, since it really is a bit of a waste of time to jump into the nitty gritty ..when the pattern is operating in a random chance roulette wheel fashion. 

Beginning of 'Convective Season' on Saturday?

Image showing 850mb (5000 ft) Dew point temperatures Country Wide . An indicator of the amount of moisture at that level in the atmosphere. Note how 'bone dry white' it is over Florida, the Northeast States, and much of the SW U.S

TODAY: That big system that swiped through Florida over the weekend was quite the dynamo in the moisture depletion category. This image above shows just that in the moisture level content over much of the eastern portion of the U.S. This could be close to being the temporal   few day period of relative drier air over Florida once we approach the weekend (as moisture increases) until the first cold snap this  upcoming winter. Very rich, moisture laden air resides toward the lower right hand portion of the image which we can look at in a moment.


All things aside , skin itching , brittle boned, eye watering, near Desert Southwest like (well, not quite) air resides over the Sunshine state through today and Wednesday. Thank goodness it will not last long lest the landmass turn into a dusty metamorphosis of random devaporizing. Poof in a exhale of dust.


All other commonalities aside, this could be the least of the last but not forgotten period of such absurdities in this category as the unclimatological winter of 2011-2012 ends and we head well into yet another season I suspect will also be non-'climatological', although in just exactly what way it is hard to say.


Quite cool this morning with a temperature around 46F at MLB alone, with the A1A strip running in the low-mid 50Fs. Today will be the coolest day of the lot around the clock. Rapid temperature drop in such conditions with the setting sun and very little wind. Wednesday morning near the beaches will be similar to today, but the morning lows will be most cool from a statewide perspective as high pressure now to the west which is squeezing out our atmosphere not only due to northerly mid-level winds off the U.S landmass, but also because we are under the descending side of that approaching system.  Sound the Severe Stability Index Alert, the sky is clear!  Wednesday to be another day like today, but the high pressure system will already be east of the state by mid-day allowing easterly winds to begin to offset the pattern, and slow moisturization commences. Wednesday will be a good 5F or more degrees warmer, but Thursday morn will be briefly 'cool' once again, but much warmer by afternoon. Heading into Friday afternoon we could be looking at  the "Big leap Forward" in temperatures while areas toward the Southern Plains are already well toward the upper 90Fs. 


Meanwhile, the high pressure starts to draw forth water from the Caribbean Well with winds from the southeast, ushering increasing moisture from the south and what looks to be a day of bona-fide thunder on Saturday toward mainly the West side of the state. This is the first day guidance has shown Precipitable water values reaching 2" since last October, and appears to be from late day convergence.

PWAT Saturday. Note all the moisture still yet to the South over the Caribbean.

 It is hard to tell from this image above, that a frontal boundary by this point in time will be sinking southward toward the state, with a better chance of showers and maybe thunder on Sunday nearly statewide, but not all encompassing. Looks like a 30-40% coverage type of day.  The boundary after this point is forecast to loiter and fizzle close to Central Florida but followed by another in similar fashion resulting in easterlies upward into the mid levels which continue to douse the atmosphere with moisture richness. Although rain chances will be bouncing around hither and yon, with rain 'chances' in the forecast more often than not, it is hard to pin point that far out in the future the detailed hows and whys other than SE flow..with possible onshore ocean showers converting to thunder along the west side. So be it, or not; time will tell..it always does.

Excellent Weather Begins Tonight

Images show line of convection moving across the state very early this morning. It appears this will be the end of any storms now in quite some time to come. The heaviest activity occurred in Osceola County into Brevard as can be seen here in both images. On the right is where the  tornado watch existed at that time for Central and South.

In this early morning water vapor image we can see clearly where the upper to mid level low pressure system was located. We can also see what is left of the line of showers and thunderstorms sparsely distributed that had gone through after midnight by the dashed white line. The low is lifting almost due north today, and thus the cold front will dawdle on through only later today into tonight on the toes of WNW winds and drier air 

Thanks to a Sky Appreciando Extraordinaire as well as gifted artist friend for helping create the new header for the blog. I had a vision, and he created it for me with his software and other talents. Kudos Mr. Jim Williams. For both the new image as well as the former banner at    http://dryliner.org/
  
TODAY: Storm system has cleared the area in regard to strong storm (or really about any storm) development. As was expressed yesterday, the atmosphere never did become unstable enough to support widespread convection as suspected would be the case. Even over night in the presence of almost no CAPE as well as some inhibition on top of that there was yet still some storms, with a warning for thunder storm winds and hail in Osceola County though. The winds aloft and other parameters related to energy and wind fields was simply too powerful to ignore, and thus the Tornado Watch. That is a good example of why they are called "Watches"..(not warnings). 


We can recall on Friday there was at one time 7 severe thunderstorm warnings statewide issued and active simultaneously.  In my mind I thought, "Ah yes, the day before the day" (of severe weather that could be very bad)..On the other hand that was quickly followed by the notion, "But is the day before the day going to be the only day?"!  It appears that was the case. ..considering all of the storm reports of hail ranging from 0.25" up to 1.25" and wind gusts in the 44-58mph range occurred on Friday (other than one or two overnight here and there).  Between Saturday and overnight to early this morning I saw no severe reports.  


LATER TODAY: Appears that the sky is taking on an almost winter appearance. It is quite blue despite the lower level clouds and renegade quick moving showers. It does also remind us that we are going to be entering the 'Convective Season" beginning around May 1, which is not the same as the 'Wet Season". The convective season is a great time for storm photography as storms and clouds tend to be more isolated in an atmosphere not yet saturated in tropical moisture, highlighting crisp edges and blue skies around them. During the Rainy season storms start to take on a slightly 'mush appearance'..but nonetheless threatening.


Today, instability is lacking, but seems to be less so than any model shows based on the Local Data Integration System out of KSC-MLB NWS Network. Some showers are occurring, widely spread, and expect the sky to be partly to sporadically  mostly cloudy here or there through 5pm, with skies becoming clear from north to south from late afternoon toward Central right at sunset. South Florida and all elsewhere will likely be absolutely clear after dark as winds remain WNW-W...as the cold front and wrap around moisture exists eastward toward sunset.  The bigger temperature drops will occur after midnight, with Monday morning lows in the mid-upper 50Fs with a WNW breeze, making it feel quite refreshing. 


MONDAY-WEDNESDAY: Refreshingly cool, window-opening overnights and ceiling fan afternoons under mostly clear skies with a NW wind by Tuesday. All evenings will experience a noticeable drop in outside air temperature within 1-2 hours of sunset through the first hour afterward...but winds will become quite light if not calm by morning on Tuesday and if not by then, Wednesday.  So far, it appears that it might not rain until sometime in early May...or the last two days of April. This month has just flown by so quickly, a sure sign of spring.

Two "Potential" Shots At Severe Weather Central

BOTH ZONES ARE CONDITIONAL ON MITIGATING FACTORS: Best that can be determined at this time , and is not entirely in agreement with official forecasts (Namely, the afternoon red zone)...is for some afternoon storms which could be severe with tornadoes possible (few if any), Gusty winds, and some hail...(possibly). The Red Zone is for this afternoon with a pre-frontal system;  then again toward or after dark toward midnight in the Purple area. Note that Central encompasses both realms of possibility; however, there is low certainty which, if either, will manifest to live up to its potential. Some guidance actually shows NO rain or very little in many areas. Wind fields are simply too tempting  (as well as threatening to ignore, especially tonight.

TODAY: Will not write an in-depth analysis or forecast post, since the upcoming day (being today) has already been looked at in previous posts, and the media is covering the situation. All in all, what is shown above is a bit not in sync with official forecasts I saw, namely for the area toward the Big Bend and east toward JAX.


Pre-system  ejection of vorticity is forecast this afternoon across the North Half. Latest RUC and actuals match up closely in regard to instability. The question becomes, how unstable can it actually become with high clouds over the questionanable area in Red? If this instability can manifest (which may or may not be in progress as I type), severe storms are entirely possible. There is cloud cover out there after all, and If not, there is a chance that only isolated activity will manifest. This forecast post is based mainly on 06z runs, and a bit of the 12Z NAM (and recent RUC). Will say that the RUC and overnight GFS and NAM seem to all hedge in on East Central toward the Brevard area during daylight today... bears keeping in mind. 


All factors of severe possible, although with such a saturated air mass hail is a bit questionable . It might be that the over-saturated air mass will be the saving grace in regard to any severe weather, or even much weather at all. Below is for this afternoon. Note the heavy cloud cover over the South. In the red is where the best wind fields are forecast as well as instability by mid afternoon. If this instability does not manifest, there is a chance it will be generic thunder and rain. Far South though, although not shown toward the Keys..could be another story.

TONIGHT: A second impulse to ride in across the South Half of the state, making an entrance toward Naples and Punta Gorda. Wind fields will enter SW Florida toward sunset and rapidly spread NE  toward Brevard on the east side and all locations South as well. The north seems to be out of the picture over night. At this time, the GFS is showing instability over South Florida and storms by mid-afternoon; however, 'actuals' are not supporting model output in this regard. Note though, that the wind fields will possibly work into that area first!..Thus, might be unwise to discard that area completely today. Basically, 2 out of 3 major models at this time of day say 'no go' for the south until at least late afternoon ...Otherwise, tonight the models all agree the better wind fields with much greater shear and helicity will be over the south half anywhere from Sunset toward 3AM time frame. There is one issue I have. That being, the best bulk shear lags ...in other words, factors MIGHT not sync up. On the otherwise, if they do or come close to doing so, it could be a no holds barred severe weather situation. It is tonight the better Theta E air is drawn nortward and south of a secondary boundary, in which case lack of instability might not be a mitigating factor. Thus, The Storm Prediction Center's outlook closely matches up with the night time scenario drawn in for the south half...as noted by the purple lines in the first image.

All will not be said and done until Sunday late afternoon or a bit earlier. Yet another questionable time frame and again, for North Central. The entire system should clear the state by sunset in the rain chances, and from that time forward cooler and drier air moves in for Monday-Wednesday mornings.

An Isolated Strong Storm Not Out of The Question, Severe Weather Threat Remains Saturday

Rain fall (green) as showers to Thunder Orange To Purple Strong storms after 4:00pm today are possible as noted in the discussion below. Note in this 1:20pm image the 'Lake Shadow" NE of Lake Okeechobee; the clearing area due to SW winds blowing across the lake and stabilizing the atmosphere upstream of those winds along the NE side of the Lake

TODAY: A bit like yesterday, just more of it. Sea breezes both coasts will play in to today. Today looks like a summer day out there, and the air feels a bit like one. There is one big difference today from yesterday, that being higher Convective Available Potential Energy (CAPE). There is more of 'that' today than we have seen in quite some time and local data integration system from KSC backs up the model's claim, if not more so of the cast near Vero and South. That air will be transported into Central after the sea breezes set up and spread around. 


Temperatures aloft today are cold all things considering so there is an added storm potential bonus. The key factor for stronger storms toward the east side will be in the timing and cloud/shower extent prior to 4pm across Central Florida. For now, will gamble on hedging toward pretending it is summer in regard to timing, and throw in the cold air along with respectable vertical velocities shown on the questionable NAM model, although other models are showing 'values' as well. Would add some 'umpf' late day along the east coast near I-95 from DAB to Vero, with a focus toward Brevard/Volusia/Indian River, and St Lucie Counties...with the chance of stronger activity noted in the purple for a variety of reasons beyond the usual 'technical difficulties" that either could be stronger parameters than guidance shows or be non-existant. Rains could persist until after sunset but not much longer as it appears now as activity moves offshore and or loses the 'juice' .


SATURDAY: This is a big question mark day in regard to severe weather. Suffice it to say it is not a day for the beach, as cloud cover or a very big bad storm threat will loom. If cloud cover is less, all the greater the storm threat, so either way...a watchful eye will be necessary. I had made up a graphic earlier today before the 12z runs, so will use that one instead of recreating the wheel which will change on the next run anyway...due to ever changing model resolutions.


Consensus now as gone back to previous reasoning, in regard to where Severe Weather in the form of 'damaging hail could fall' as well as where/how/why there could be some tornadoes on Saturday. 


Instability (CAPE) is not all so impressive (not at all actually) , and the wind fields have been bouncing around a bit in regard to whether or not there will be anything beyond an isolated spin up VS. an actual full blown tornado or so...if not a few. Last nights hodographs which show the curvature and strength of the winds aloft portray a definite chance of tornadoes during brief windows of  so called "opportunity" from SW Florida up toward Ormond Beach, (if not outside those realms) with the conditions spreading north from mid-morning toward late afternoon as the day progresses. Otherwise, other showers could occur elsewhere. There has been some trepidation from official outlets against the chance of strong updrafts, as noted yesterday, due to weak instability.


However, I have noticed that low lifted condensation levels continue to be forecast by early afternoon (values we'd normally expect not to see until near dark, when summer storms get there strongest) to be unusually low, meaning LOW storm bases...and that factor compiled with Rich Theta-E air well up through the mid-levels and good helicity values could overcome any weakness in instability regardless.


One other factor to point out is that this does not appear to be an in and out of here situation by any means. With a threat of severe weather as far north as JAX toward Tallahassee and as far south as the Keys at various time frames due to what might be TWO warm fronts swiping from south to north..timing is literally impossible from my perspective at this point. The important thing to bring forth and stress is to STAY AWARE! This will not be your standard 'severe hum-drum fare" type of day, especially if a worst case scenario were to evolve. Do note, the low is forecast to form near the Loop Current, so unexpected intensification of that surface feature over those warm waters could make the difference between a slight risk of severe to a booster shot up toward a rare moderate risk, unless a high overcast and the theta-E air does not manifest as forecast. In which case, one will be left wondering what the fuss was all about for the get go. The above statement was not made by any office, but best to stress worst case than be  nonchalant and off guard to any sudden 'potential'.

This image as noted is based on the 06z NAM run valid for 3z tomorrow night (11pm). Later runs match closely in regard to the main features but change with the finer details as to where, when, or even IF severe weather  will occur. The image portrays  Helicity in the lower levels of the atmosphere. Since that time, the values have changed in the forecast, but who is to say they will not change right back again later on before tomorrow morning,? Thus, I posted this as an example showing a warm front location and surface low for Saturday night around 11pm. Values by this time have spread for South Florida northward during the day with a severe threat as that occurs in this 'Example". Those values are high for Florida and not messing around. Serious stuff in other words.

The good thing is, guidance does show that it might not be a good day AT ALL to plan outdoor activities, so there is literally NO EXCUSE not to have a TV on Channel 13 (Central local channel), or your favorite news channel, tuned in and ON otherwise. If things do get cranking, your news channels will be covering tomorrow Live and Real time, possibly commercial free during any high points. So far, tomorrow has had a greater potential for severe weather than we have seen since last spring in the hail and twisting winds category.


Here is another interesting observation, the  forecast sounding based hodograph. The big loop , or arc, shows how winds curve with height within a Theta-E rich atmosphere. In fact, one of the downfalls for severe tomorrow will be that the entire column of the atmosphere in any storm will be saturated beyond recognition..but low level forcing along northward moving boundaries with energy criss crossing from the west could set just about anything off, any time from late morning through early evening.

In the upper right is the winds with height. Note how quickly they turn, or shift in the low levels. Also note how close the vertical red and green lines are. That shows gobs of moisture without any dry slots to aid in lift, or buoyancy. The lower left is the main point I wanted to point on in thee wind fields...LOOP! To the right, we see this hypothetical 'sample' is for a location near Titusville.

BE AWARE point blank. Things can change in later forecasts, and I expect everyone on TV will be saying the same. Or they should be.


BEYOND: Activity could continue into early Sunday toward noon time with a lull in activity somewhere along the line, but it appears any tornado threat will be gone after the wee hours of the night. There is a chance the entire mess will be over with by noon most locations with rain and thunder North Central to North, but as noted already, there is simply too many timing issues to make even close to a believable or rather trustworthy forecast regarding Sunday's weather. Need to get past Saturday yet still.


Otherwise, no rain for many days seems to be in the cards with much cooler morning lows interior Central and North, and quite cool comparatively speaking elsewhere for several mornings. North Central could feel 'chilly' prior to 10A<. Afternoons will be quite pleasant though.