Fall Has Trickled in On Cue , More Through Monday A.M.

'Last of the Great Mohicans' ( of Summer Storms) - Severe Thunderstorm Warned For Sharpes to Port Canaveral - Approaches Port Canaveral late yesterday afternoon. From here on out, most thunderstorms until next spring will be driven by synoptic scale features other than sea breeze/lake breeze mergers. Actually, the true purely summer like storms ended in late August (those driven by solely lake/sea breezes). But for even the non-purist,  Fall has arrived. The other stronger storm occurred in Dade County toward sunset.

TODAY: The primary frontal boundary passed through my location at 5:12AM this morning noted by a slight uptick in the NNW wind and a whopping temperature drop of 2-3F degrees over the first hour. The morning low at my location was nearly a bone chilling 72F, the coldest since early May. A secondary boundary looks to drop down the state during this afternoon, crossing the Beach Line to Tampa around 4-5pm. This could be accompanied by a secondary wind surge lasting for an hour or so after dark. It is with this boundary the drier air (lower dewpoints) will move in, but for the most part coastal East Central and South Florida will never reach the itchy skin and brittle hair stage of dryness like that of winter. Not so bad.  This 'surge' is expected to continue to south Florida through the mid-evening hours. There might be a small line of clouds with this feature, but nothing more other than perhaps a shower along the Palm Beach County coast toward sunset, but even that chance looks very low. 


TONIGHT THROUGH MONDAY MORNING: The weather pattern over Florida will be influenced by the monster low pressure duo that has been near the Great Lakes all week which is finally pushing out in two phases. The first low is now in NE Canada, with its replacement nearing West Virginia. It will take through Tuesday for the entire system to fully pull out and be replaced by high pressure pressing in the from the west as well as from Canada. Until that time, and during the transition , we can expect two more wind surges. The first and less noticeable one (after today) associated with the first high pressure building in toward the Mid-Atlantic states later on Monday afternoon, and the second and deeper push with the second reinforcing high pressure Wednesday afternoon. Until that time it will remain dry, with some stratocumulus clouds (stratocu) beginning to be seen, mostly along the coast later Monday or Tuesday, and then some low topped showers possible remaining offshore, very isolate, with more stratocumulus clouds of greater vertical depth later Wednesday.


Here is the current pattern, with the low near West Virginia and the subtropical jet across South Florida. This area (South) is most likely to see some jet stream cirrus, if any is to be found the next few days). Wet conditions continue off and on in the Northeast states as lobes of energy rotate around the low pressure area.

Another way of looking at the above infrared satellite image, is to use visible imagery. This is included to emphasize the amount of low and mid level cloudiness associated with the low pressure area in the NE States and New England areas not otherwise so apparent in infrared imagery. Also note Major Hurricane Ophelia on the right side of the images. This has been the most 'classic' looking storm of the Hurricane Season, after having been nearly downgraded  to a non-existent state just the other day:

TEMPERATURES: To simplify matters, I created a sketchy sketch  in general noting where the coolest and warmest mornings will be Sunday/Tuesday mornings. The least cool areas will be the outer barrier islands of Brevard (east of the Banana River) and coastal SE Florida south of West Palm Beach east of US1 and through the Keys and all of southern   Collier County. The warmest days from today through Monday will be near the Beach line to South Tampa Bay and south where highs could reach  80F toward the mid 80Fs toward Lake Okeechobee and south. North of that line temperatures might never reach 80F degrees for the next two days. The warmer overnight areas will see lows around 63-69F and cooler elsewhere varying from the mid 50s to even the lower 40Fs toward Tallahassee/Crestview. I'm still shooting for 67F tonight in Canaveral, although Monday morning might be the cooler of the two mornings. During the afternoons, winds will become more northerly or NNE, but will die and become more NNW-NW overnight and early morning. By Monday afternoon before the first of the two wind surges winds might go to near calm for a period through early afternoon.

White: warmest overnight lows, dark blue - coldest

 


WEDNESDAY NIGHT - FRIDAY: It now appears it is with the second wind 'surge' from the ENE (which will be more noticeable with breezy 15 -20mph winds along the coast), that the chance of rain increases mainly heading toward sunrise Thursday. The vertical depth of this wind will extend upwards of 10,000ft uniformly with the surface wind as opposed to a shallower 2-6000ft wind on Monday/early Wednesday, and thus, cloud tops will be high enough to be rain producers. The strongest winds will remain just offshore but will be  extended  faar out into the Atlantic for hazardous boating conditions. Rains initially, assuming they do develop which looks like a good bet, will impact only areas east of I95, but with continuation of the winds they could extend toward the west coast by later on Thursday.  It should be needless to say that with the deep onshore flow passing over ocean temperatures in the low-mid 80Fs that temperature (air mass) modification will be in full gear ending the relatively 'crisp' autumn feel to the air. Overnight lows and daytime highs along the coast will hardly vary diurnally by 10 degrees with lows in the upper 70Fs at the beach with highs in the low-mid 80Fs depending on how much and where rain falls. Away from the coast, temperature variations will be much greater.


Southeast Florida might remain dry through Thursday, with the main impacts in the rain buckets being from Indian River county and north to JAX, but after the second surge, winds will become progressively more easterly which puts all of Southeast Florida in the picture, with the potential for Bahamian induced 'streams' impacting the Palm Beach area if the wind can veer enough from due east to ESE.


Special Note: If you don't like prolonged east winds, get used to it now, because it looks like they will be in the picture through the entire first half of October (at least), and probably even longer.


EXTENDED HEADING TOWARD OCTOBER 15: The pattern can't last forever, and as such, the long range GFS model has been portending tropical development in the Caribbean if not toward the SE Bahamas. Then again, the GFS has been showing the same type scenario to occur in the long range for 10 days now. Believe it just might be for real this go around, or rather, if were ever to happen it should happen then. Reason? The frontal boundary, what is left it, will end up draped into this area for quite some time to come. This is the time of year for tropical systems to form along these decaying boundaries.


Oddly, though, another scenario has unfolded as well the past 36 hours. That being for a severe weather event in the SE states heading toward the 19th...as well as a tropical system. In any case, it looks like the last half of October could get interesting in some form or another. 

Pot-O-Gold Storm Friday. Note the rainbow is visible in the breakers. This rainbow heralds the end of summer and the beginning of fall. Some see gold for such a time, but others, it's a pot of coal ...the end of summer storms.