WEATHER MADE CLEAR FOR ALL TO HEAR

"But seeing they could not See; hearing they could not Hear"
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"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, May 14, 2011

Potent Storms From West To East Possible Today - Isolated Hail Would be Likely

LATEST INSTABILITY INDEX VALUES: HIGHEST ACROSS CENTRAL, LOWER SOUTHEAST BUT STILL VERY UNSTABLE THERE. STORMS MOST PROBABLE IN THE BLACK LINES. LEAST LIKELY FAR SOUTHEAST FLORIDA INTO A PORTION OF PALM BEACH COUNTY. STRONGER STORMS POSSIBLE IN PURPLE. WITHIN WHITE, COULD GET CHAOTIC FOR A BRIEF SPELL IN ISOLATED POCKETS. SEE BELOW FOR WHY.

SYNOPSIS: A large upper level low pressure system over the Eastern U.S. is slow to move out due to a blocking pattern. A cold front has cleared the western Panhandle, but might not clear the peninsula fully until late Tuesday. Until that time, periods of unsettled weather in the form of showers and thunderstorms can occur..separated by periods of pleasant weather and less hot temperatures than days past.

TODAY: THE FRONT IS THE BLUE LINE. A COMBINATION THERMAL/PREFRONTAL TROUGH IS ANTICIPATED TO BE FORMING AS A TYPE. WEAK SURFACE LOW SEEMS TO BE FORMING NEAR WEST PALM, OR IS ANTICIPATED. IF SO, THIS TROUGH WOULD ALLOW A SEABREEZE TO FORM NORTH OF THE LOW.

 NET RESULT...CLASH OF THE EAST AND WEST COAST SEA BREEZES CLOSE TO OR EAST OF I-95 UNDER VERY COLD AIR ALOFT


TODAY: As shown in the above image, a cold front is still far away from North Central to South Florida. Unlike the winter months when they blast through, this one will take at least 60-72 hours to push through. Another impulse (upper level disturbance) is expected to cross the Peninsula Early tomorrow, potentially bearing a 'pre-disturbance' trough as well..


Meanwhile...


The west coast sea breeze will be dominant today within the synoptic scale pattern of west to east motion. Only far South Florida is not within this pattern...with the weather down in Broward, Dade, and Southern Palm Beach County being dictated by more of a sub-tropical nature. 


A disturbance is FORECAST to move across the state today. Within it could be isolated to possible scattered thunderstorm activity. If so, (still tapping my fingers and waiting)...storms will strengthen with time as the develop after 2-3pm as the cross the trough shown above. Some of these storms in isolated fashion could contain small coin sized hail. Unlike yesterday, the sea breeze IF IT DEVELOPS would be East of  Orlando Metro and the Airport, but I see that the NWS might be putting that area on somewhat of a 'Heads Up" mode for hail and/or stronger wind gusts due to the passage of proximity of storms in both MLB and MCO. JAX has some severe storms approaching already...this was indicated to occur my most (but not all) model guidance).


As we see in the first image, I've somewhat 'color coded' where storms might become stronger and then strongest mainly along and east of I-95. CAVEAT: Much better news if the east coast sea breeze does NOT develop. It is almost hard to envision that it will not though, given that on the beach in Cape Canaveral the west wind is only about 4 mph. My initial line of thinking is that at least a weak sea-breeze would form after 1-2pm..if not sooner given the current conditions. 


Dew Point temperatures across Central Florida are running in the low to nearing mid-70Fs in pockets. It is a bit cooler so far today, but it's still early. Some of this moisture will hold in the normally warmer afternoon heat, and reserve it for release today in the form of Convective Available Potential Energy (CAPE). The higher the CAPE..the bigger the release. Vertical Atmospheric Upward Velocities (VVs) are being forecast to be strong..and in one instance..were forecast to continue upward right up to nearly the jet stream level. This would keep downward descending parcels, i.e. rain drops)..from falling to the ground until they are heavy enough to do so. Morning soundings are showing a dry mid-level layer..adding to the mid-level buoyancy (lifting mechanism).  


1) If the sea breeze does indeed form..and that is questionable...storms could become severe in some areas as they begin to the most western impingement of the sea breeze front. One model indicates very high precipitation totals just east of Central Florida in the very late afternoon hours...indicating the activity will collapse quickly and possible drop a lot of hail in the process and gusty winds out at sea. However, should the collapse occur sooner, the would translate on the coastal communities.


2). If the sea breeze does not develop..storms would not be nearly as strong with all potential negative factors greatly reduced by a very wide margin. 


3). Third..the obligatory worst case scenario. As long as there is a glimmer of doom, might as well capitalize on it. It's only a blog post anyway. If you've read this far, you'll be intrigued if nothing else: 


The sea breeze does form and is magnified around the crook of the Cape area..or Cape Bight which runs from Port Canaveral out past the lighthouse. Mesoscale (small scale) circulations would form  (like they always do in such cases) within that zone and west into Titusville, Mims or even Oak Hill toward Sanford depending on the strength of that sea breeze. This would be a concern for the region in North Brevard toward Sanford and Southern Volusia Counties. Namely because the further north one goes the stronger the winds aloft area as well, which would support even yet bigger storms capable of dropping golf ball sized hail at least. I do not think that will happen, but it is something to passively watch consider there is a Shuttle Sitting on the Launch Pad.


In general, the strongest of storms, if they form, could run within the bounds noted above, or from Jacksonville to West Palm Beach. As of this time (and that could change), the Miami Metro area and Ft. Lauderdale do not in any way seem to be in a threat zone...not for today that is. This will possibly change with time in the next two days, contingent upon how much further South that big upper level trough digs south. We'll know on Tuesday.


And finally, I do have second thoughts about how virtually ever single model portrays this afternoons events. Perhaps something even more 'squirrelly" will occur near the coast, if so, most likely near the Cape area within 10 miles.


SUNDAY: Could be a stormy day over Central Florida again, but very isolated. Or, simply a bit showery with some afternoon thunder. Worst case scenario is that the storms move offshore tonight (if they even form as noted in length above) and collapse, sending an outflow boundary back to the coast. This would provide better impedance for a sea breeze to develop once again on Sunday...very sketchy though. Things have changed since last night's model runs, and I FULLY expect things to change at least two more times before the next post is made.


With that said, it would behoove "High Speed Dirt" to continue ad nauseum before today is even yet through. Much of what happens today might provide a hint as to what would occur on Sunday.


MONDAY: Between disturbances. Looks very quiet although an isolated shower or thunderstorm could occur, but only isolated and remote.


TUESDAY: South Half of Florida could have the better chance of showers and thunder, but it is very very sketchy what form the precipitation will take. Could it snow there?! (just checking to see if you read this far). 


 Best chance of thunder appears to be far South Florida despite the fact that the strongest winds aloft, which are pretty impressive for this time of year, will be over Central and South Florida. If the precipitation shown in guidance is thunder storms..they could easily be severe. Time will tell..I'm on the cusp of very uncertain about Tuesday. Beyond Tuesday...the coast is clear, literally...SE Florida? Maybe Miami Metro.

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