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

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

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

Saturday, March 31, 2012

Outside Activities Should Be on Alert for Stronger Storm Potential Today

Late morning visible satellite imagery distinctly portrays a 500mb vorticity max near the Panhandle (V) moving toward the E-ESE. Forecast models show two players 1)Potential side-shore to onshore east coast sea-breeze East Coast in predominant west to east steering flow aloft and ahead of the "V" and (2) Highest instability toward the south half of the state later today due to the north half (where stronger  mid-level winds preside) high level cloudiness. Thus, the Golden Magic Dividing Rule Lline across Central applies to "some degree" given this time of year of early spring. Best wind fields north, best instability south. WITH, the additive bonus of the 500mb V-max rotating across. Guidance indicates this might break up a bit this afternoon toward the south, running over an east coast/west coast sea breeze convergence toward I95..however...(read on)... 
TODAY: Not too much change in yesterday's thinking as an upper level vorticity max at 20,000 feet (500mb) is noted in the image above by the red "V". In animations, this appears as nearly a closed low pressure system which one would be otherwise be prone to assume was the case without model guidance and surface wind observations. 

This area is forecast to move E-ESE today and across the north half of the state, while lower level winds and frictional effects could generate low level vortictiy and coastal helicity along and east of US1 up the east coast of the state from east coast sea breezes (this is a prime assumption however which can make or break storm strength anticipations!).

Several thunderstorms have already moved across well toward I-10 today, with greater coverage expected to blossom from 1pm on AHEAD of the vort max as lift increases with daytime heating added upon with daytime heating ahead of that feature. A 300 mb jet streak is expected to strengthen toward the base of the 500mb feature across South Central Florida today, squarely placing a portion of Central Florida toward the right entrance region which would increase lifting mechanisms in the mid-levels of the atmosphere adding to upward extent of storm tops, however divergence aloft does not like significant with that feature. This factor, combined with a possible additive factor of low level convergence of the westerly wind / west coast sea breeze confronting the east coast sea breeze front could add additional low level lift from DAB (Daytona) toward Ft. Pierce inland toward I95. 

The factor that would preclude greater lift is that storms should be moving rather quickly today, leading little time for wind field dynamics to assimilate.

There is one other factor to consider however that none of the models have depicted. Should storms to the north escalate 'as expected' and begin to collapse due to anvil storm tops approaching the Tampa Area, that activity could get squelched out from  shaded sunlight, and their collapse could manifest as a large OFB (outflow boundary) propagating toward the ESE -SE which would race ahead into better heated areas to the south under the jet streak winds aloft. 

Anvil tops should stream off toward the ENE today..leaving those areas south of I-4 in better sunlight once activity starts to develop. Outflows have a funny way of moving under areas shaded from above.  With strongest jet stream winds south of SR 528 aloft moving from west to east..if any activity racing and forming in outflow could get either sheared apart or actually enhance, especially along a triangle running from DAB - Altamonte Springs - Kissimmee through the north 1/2 of Osceola County and off the east coast between Vero and Ft Pierce with an even small area as shown below harvesting a higher potential. 

Due note, this image is in considering that an OFB would form, otherwise, much of the activity along the Central Portion of the state might not be as strong, especially if an east coast sea breeze does not form:

RUC Analysis (Rapid Update Cycle) from 11AM shows the vorticity max at 500mb This is over-layed with radar actual, note that some activity has formed AHEAD of the max in the eastern Gulf.  
CONCLUSIVE WORST CASE: Possible strong and ' near severe storms' near Tampa and North as well as near Vero and North especially, with a possible outflow line of storms dropping ESE-SE from North Central Florida later this afternoon after 2:30pm. All guidance indicates activity will conclude by sunset, but timing could be still a bit of an issue considering an aspect of where heating occurs and whether or not an outflow forms, which again, is contingent upon stronger storms forming toward Cedar Key to Gainesville to Ocala areas by early afternoon. If so, strong storms possible in those area with the treat being strong wind gusts in excess of 50mph, and would not be surprised to see stronger gusts toward the East side in the orange and even black areas above if said outflow materializes.

SUNDAY: It appears the front will clear Central almost about the same time the front last Sunday had cleared the area. It will have no effect in regard to temperatures, only to dry out the atmosphere 'A little". In fact, only a warming trend is indicated, with potential 90F + readings popping up for the first time since last September.  

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