"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".

Friday, June 28, 2013

Thunderstorm Pattern Continues to Change Each Day through Wednesday

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.

(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.  

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.


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.

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.


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