Continued Chance of Brief Heavy Showers / Lightning Hazards - Some Possibly Quite Strong

Early morning radar is shown . Showers/storms should move from the WSW to SW today around 15 mph toward the East Northeast (ENE).  Earlier onset toward the east coast once again, but timing will be everything again today. The later the onset, the stronger the storms can be ..with one big 'ouch' in the forecast per the RAP Model noted below

TODAY: More atmospheric moisture today than yesterday with another earlier onset of activity expected. Numerous small showers to develop mainly toward the west coast and spread eastward  accelerating along the west coast sea breeze front. With faster motion and plenty of instability today (more so than yesterday) some areas might experience rain more than once. The earlier the activity reaches the east coast , e.g. before 3pm, the lower chances of significantly stronger activity there will be.

The unusually amplified pattern of " trough eastern U.S. and ridge Western U.S."  (making for record highs in the Desert SW such as at Vegas and Needles where it reached 123F yesterday) will continue to amplify today. meaning the trough will be digging further south, and the ridge out west will expand northward will into Western Canada.

The RAP model suggests that as the upper trough digs to the west of Florida a bit of short wave trough at the low level will cross mainly the North Half of the state. In response, the surface winds near the east coast could back from SW toward to more of a southerly to SSE direction by early-mid afternoon.

As such, convergence at some localized eastern locations could result in strong storms with heavy downpours and wind gusts near 50 mph and frequent lightning, especially east of I-95 to the beach areas. There is no especially favored area, although there is a chance of the strongest storms occurring over the Panhandle to Northeast Florida. Latest RAP goes as far as showing a strong storm over Brevard by early afternoon. On the other hand, other models show no such backing of winds, and thus more of a generalized spread of showery activity much like yesterday.

MONDAY: This day still appears to be the most active day or similar to today (so far). Slish slosh and add some soap cycle.

TUESDAY: Another active day with a gradual pattern shift . Winds becoming more S-SSE paralleling the east coast while moisture depth continues with moderate instability. Strong wind gusts and frequent lightning still possible in bursts of heavy rainfall. Tuesday will have a different all around 'feel' to it than today and Monday.

WEDNESDAY: Can it drag on yet one more day? Maybe, but this particular wet pattern cycle will be nearing completion before we enter spin dry.

THURSDAY- Fourth of July: This appears to be the driest day of all through next weekend, with the majority of rainfall toward NW Florida and the Big Bend prior to the Final Rinse cycle.

BEYOND: The GFS and ECMWF are showing a resurgence of moisture from the ESE (East Southeast) as a tropical wave approaches the state , if not two smaller 'ripples'. In as such that the east coast could see earlier morning activity spreading west during the day, and perhaps on one day toward Saturday it won't make any difference what time of day it is that rainfall could be experienced. Rinse cycle begins Friday.

"Ocean showers" in the atmosphere being depicted can be surprisingly quite heavy with a brief period of wind gusts near 40 mph if this pattern does continue to emerge as guidance shows. After next weekend though, significant drying is shown with a down time after around the 10th of July statewide.

A Perchance Random Strong to Severe Storm Possible Again Today

"HOVERING "

"LOCALIZED FLAIR"

YESTERDAY: Not much different today than yesterday regarding forecast accuracy which is a bit of a 'make no promises, incur no loses' type forecast on this end. Today does look quite a bit different in general than yesterday, at least as of 10AM, but from that standpoint everything is happening as expected: "Predictably unpredictable". 

Images above are right on to near about where the seabreeze was able to reach yesterday which was the sand dunes. However, a side shower / up river wind component was able to form at ground level, hence a water spout along the Indian River was reported toward South Brevard as some storm action from the west moved over the river. It appears per latest guidance (short term models) that an up the coast type wind might once again develop today after 2pm or so, but will remain close to the beaches. The above shown (image) formation appeared to be resultant from the side shore wind meeting outflow from a storm to the north that was working southward just offshore. There was some weak rotation associated  with it, but in  no way was it close to 'significant'.

TODAY: SW flow aloft continues with 'pockety' moisture in various levels along with a mesoscale boundary or two which could again act as catalysts. It appears one such boundary might be running near to just north of I-4 as a result of outflow from early morning activity further north. Today does not look quite as unstable though as yesterday did at this time nor are any mid-level boundaries discernible (as of yet).

Regardless, will play for the worst as noted below for various locations as a shot from the hip.

SOUTH FLORIDA is again questionable. As of now this area is showing up on Mesoanalysis as very stable with the most unstable area being Central Florida. North Florida is being stabilized by early day activity already.

SIDE NOTE: Jet stream level winds today are  from the NE to Southwest (which is a bit odd), so anvil tops on stronger storms will blow AWAY from the east coast and toward SW Florida with time. That might be enough to shut activity down that way to a grinding halt due to the shadow of the anvils stabilizing the air below but that is well down the road into later today. Otherwise, will watch some pockets along the intracoastal or even immediate beaches again today mainly from the north side of the cape toward Vero Beach or Ft Pierce.

If activity begins to form too soon along the west side of the state and marches east before any side shore component can form (or if it forms), most if not all of the strong storm chances will fall almost away entirely except possibly toward I4 or maybe in SE Florida.

BEYOND: Even less chance of a side shore wind in the next day or so, but Sunday and Monday both appear to have a better chance of being 'wet', especially across all of Central and South Florida in various locations. By Tuesday the steering and surface flow is nearly from due South or SSW which sets up a different set of circumstances entirely, along with better upper level divergence as the upper level trough makes it's deepest southward plunge before retrograding away toward the NW and filling in, losing all identity by mid week next week.  

The most obvious all out reduced day for rain chances is Thursday and beyond for the most part (for quite some time really) but not entirely so..afterall, it is summer in Florida.

                  "LONE SOUL"

Thunderstorm Pattern Continues to Change Each Day through Wednesday

"VACANT LOT"

TODAY: Early morning guidance is all over the place regarding this afternoon and short term guidance changes seemingly every other hour in regard to what is going to happen where this afternoon , so only a 'be advised' that after the time of this post things will likely change again.

" PORT CANAVERAL PALMS"
(June 27th, 2013)

Upper level trough (eastern U.S.) and ridge (west U.S.) continue to amplify today through Monday. Net result in the Desert SW will be hot and dry,  unusually so. Death Valley is potentially going to break a Record High for recent times but not to eclipse the 132F set long ago. (but who can say for sure). By Tuesday this pattern will begin to retrograde westward and fall apart with the dominant feature being high pressure building SW ward from the Northern Atlantic (below) . That will bring onshore winds and an end to thunderstorms, maybe even for the west coast since they may not be able to develop a sea breeze for a few days. Meanwhile ....

Locally, upper level winds are shifting a bit and an MCS (mesoscale convective system) is expected potentially to impact the panhandle region tonight. Morning sunrise showed ACCAS (altocumulus castellanus, "Castles in the Sky") clouds overhead the CAPE area which do indicate mid-level instability which could mean strong to severe storms, but the low levels need to 'couple' with the mid-levels in order for this to do so, which does not appear will be the case today, if even the same mid-level condition even exist later today.  

"CANAVERAL ACCAS"
Friday, June 28th 2013

SW surface winds today will make the east coast sea breeze hard pressed to form north of I4, the stickler today is that the state is divided by nearly 3 possible influences independent of each other.

SOUTH: Sea breeze likely from Ft Pierce and South with slower steering, better sea breeze convergence could lead to some stronger storms near Lake Okeechobee-sea breeze mergers. Guidance is split with either strong storms in the region to nearly no storms at all which seems a bit extreme, although latest guidance in some shows the mid-levels almost too dry to support any activity at all which is likely why the 'dry' is shown. For now, will ride with storms down there if not at least toward Ft Pierce south to West Palm Beach in general.

NORTH: Latest Mesoscale analysis is showing already very high Convective Available Potential Energy advecting onshore in the order of 5500, compared closer to later today of 3000 Central zones. If storms can't get going along the sea breeze fronts earlier over the Panhandle, they could be in for some stronger activity later tonight coming in from the N- NNW.

Activity today should remain fairly isolated, especially Central until much later today. Earlier activity South Florida (as usually is the case) could send outflows northward (if it can form). Latest RUC is showing an unusually strong side shore like 'sea breeze' boundary right up the coast late today which can spell 'trouble' for the northernmost Barrier Island area toward the Cape and up to New Smyrna as activity approaches from the west with steering today from west to east at 10-15mph.  Any storm that could latch on the boundary and build south against this breeze could pull off some surprise stunts, but such situations are unforecastable in advance and very rare. 

It   appears at this time the North Half of the state is being indirectly influenced in the mid-upper levels by the remains of an MCS from the Great Lakes region two days ago as some cirrus and altocu is working from north to south early today. Additionally, it appears some sort of 'faux' mid-upper level trough might set up somewhere between I4 toward 528 as the day wears on which could act as a catalyst for late day to early evening storm initiation outside of the normal sea breeze -lake breeze activity.

"PORT CANAVERAL ARCUS / GUST FRONT  VISTA" 

If the GFS is correct, there might also be a bit of dry air across Central. About the only thing consistent today with yesterday is that activity toward East Central might end up initiating as a result of activity (winds) mergers with outflow from the south . The other option is the activity from the south works north;  or lastly,  that there will be several rounds of showers and some thunder east of I-95  depending on one's location (in regard to the area from Melbourne and north. 

In brief, it's still up in the air just exactly what and where the weather will happen today in regard to rain and thunder. Some strong storms possible as shown in the image above depending on the which scenario, if any of them, evolves.

"STORMY COLOR CONTRAST SUNSET, CAPE CANAVERAL, FLORIDA"

BEYOND: Each day varies, but thunder appears possible through Tuesday. Then there is a dramatic pattern shift by Wednesday with the potential from tropical wave like moisture to affect the state Thursday and Friday for earlier day activity as the pattern retrogrades and high pressures builds toward the U.S. east coast from the NE and east.

"DISTANT RAIN SHOWER REFLECTIONS'
CAPE CANAVERAL BEACH

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. "

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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)