"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".

Monday, September 22, 2014

Possible Large Rainfall Totals Through Wednesday, Isolated Strong Storms

PURPLE: Inverted mid-level trough extending from Southern Gulf Region
BLUE: Cold front dropping toward that above mentioned trough
NOT SHOWN: very weak surface boundary near Southern Lake O.

TODAY: As expected might be the case, we've entered the realm now of do or die so to speak in regard to 'live by the models, die by the models' vs. fly by the seat of your pants mode. 

Greatest instability per models is South Florida once again but again it will all be contingent on where high cloud cover over rules (resulting in less rainfall) vs upper level winds and divergence (North Florida).  Guidance is playing pretty heavy along the west coast near Tampa Bay inland half way across the state in general and NE Florida late today to early evening from a frontal boundary approaching that area. Suspect due to the most cloud cover and rain fall , storm activities will be along to south of the mid level 'purple' trough axis shown above southward to Brevard County toward Sarasota with a stronger emphasis by far toward the west side. 

Reason for that being that though upper level winds are stronger now than they have been all summer, those winds can also spread high clouds toward the east side well before stronger or more heavily moisture laden storms can form there. On the other hand, storms could form there regardless if the timing is right. if you've noticed there has been reference to bulk shear or wind shear for quite some time in the post, namely because in the summer there are no strong upper level winds almost the entire time. Fall is slowly nodding this way but so far doesn't seem to eager to enter the tropical realm too soon (not at least into the first week of October). 

Further South, storms could occur here as well but for a slightly different reason. Slower storm motion here might actually produce larger rainfall totals due to slow storm motion, but no storm today is going to be moving very fast anyway. Training could even set up somewhere but ultimately end up as a blanket of light/moderate rain over a large area lasting well past dark wherever that might happen to be. Though some storms could be strong, the best chance appears to be late toward JAX and south toward Ormond Beach and more toward the coast of West Central Florida otherwise.
 Another area might be toward the South Half of Brevard/Osceola/Indian River County but those are only potentials, not givens.

TUESDAY: So far this morning the models of NAM and GFS origin imply a somewhat wet day with an early start. Now, that might again only be cloud cover as opposed to rainfall, but with several mid and surface boundaries in our midst with accompanying upper and mid level vorticity (wind energy) near by rain could fall beginning well before noon. On the other hand, if it holds off, storms could again become strong.

TUESDAY LATE -WEDNESDAY: No two days ever the same and this will be more so in this transition to another pattern yet none all the less continued wet as the end result. Only WHY it will rain could be for a totally different reason. 

Mid level trough to dwindle but flow switches to off the Bahamas as noted yesterday in the lower levels with more easterly but very light surface winds. This could set up a training affect along the east coast from Indian River County toward Brevard but exactly where and even IF this occurs will be, as usual, unknown until it actually begins (if it does).

The NAM has joined the ranks as of this morning of an older GFS run which really raises some flags regardless of what a newer GFS run is implying. The last one I saw was now back to more rains along the east coast for a day or two then it all folds together to cover the state in various ways into Thursday at least. By that time, we've extend our welcome and can no longer rely on guidance given all the above confusing circumstances.

For all we know, a weak tropical system could   form  during this Particularly Messy Situation  in the eastern gulf (un-named, but pretty much doubt it would be but subtropical of origin anyway).  

Large rainfall totals could arise sum total of all days put together by Later Wednesday due to all of these extenuation circumstances, not that some heavy rainfalls haven't already occurred in isolated instances on days during the summer, only it appears more possible over a larger area during this time frame. Man your rain gauges!



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