|Exploration Tower - Cape Canaveral, Florida|
THURSDAY EVENING/OVERNIGHT/EARLY FRIDAY:
This is the period of concern and in question which all eyes are focused on. A weak surface low will be forming in the Western Gulf as an upper level circulation and associated energy field (vorticity) progresses from west to east from the Baja and across Mexico. It appears the surface reflection (weak low) will be picked up by the upper level feature and create a better organized system to move ENE to eventually NE along the northern Gulf Coast from Southern Louisiana toward North Georgia.
Meanwhile, big changes in store for Florida overnight Thursday night.
The GFS and to some degree the NAM have come into agreement that a 'pseudo-warm front will form then lift north from South Florida.
Most discussions concerning that boundary take the boundary north of I-10, but for blog purposes will state that it appears the 'true warm front' will remain near to south of I-4.
The other would be an 'elevated warm front' at 2000ft AGL (Above Ground Level) which makes it much further norht. This is shown in the following image - and reflects only what the latest guidance has shown. Chances are, this will change several more times.
Otherwise, it appears there will be two areas of 'concern' regarding the overall scheme of things.
Toward North Florida is where the most rain might fall in association with one vorticity max. Another might be further south to cross 'somewhere Central Florida". Rainfall further south might get very heavy, but the fast storm/shower motions should prevent there from being any large accumulations in this area.
If there is that secondary vort max further south, it will pass over head the more 'surface based warm front' laying across 'somewhere Central Florida".
By experience, this boundary is often forecast to lift further north than it actually does, but will ride with the Central Dividing line (show below).
There is no question that ample shear: bulk/directional - will be overhead but instability is sorely lacking at least at first.
Low CAPE/high shear is typical in the winter months during severe weather events - and the 'worst' weather usually occurs along these 'pseudo-warm fronts' where helicity is maximized along with the higher dew points along and south of that boundary.
Coastal Martin to Brevard are areas of interest as are coastal areas of SW Florida toward Cedar Key/ Brooksville regions since over night Thursday night solid SSE winds will form and advect warmer Gulf Stream relate air up the coast. Thus, some surprise showers with maybe even thunder could occur well in advance of where eyes are focused on. These too, are worth mention which would occur before sunrise (after midnight).
Storms, if any, could rapidly change character if so within about 20 miles of the east coast especially as the wind fields aloft will be quickly changing character (strength and direction in a short time frame between midnight and 7AM Friday morning).
So far, best chances for 'severe' type weather would be for the east coast from 4AM -10AM in possibly two separate scenarios to unfold as the surface trough approaches form the west.
The biggest threat is wind which could gust well in excess of 60 mph (would it be too much to gander a random report over 75 mph?) though a tornado cannot be ruled out, especially near the surface warm front and/or close to the east coast from Cape Canaveral and south toward Ft Pierce.
NOTING: The Storm Prediction Center and NWS Offices are watching for 'severe' in their wordings, though SPC is taking the much more conservative approach, mentioning only thunder and possibly an isolated quick tornado. Overall, it appears parts of the state might fall under what is termed a "Marginal Risk" due to the low instability situation and isolated nature of any 'severe' storm like activities.
The system will swiftly move through and the 'all clear' might be heralded by noon time Friday with brisk winds to follow and actually warmer temperatures than recent days (70Fs).
Another system is in the cache though for early Sunday. This one too, will be tricky. Suspect some of the moisture will be scoured out by the first system; but on the other hand, some of the wind fields are almost more impressive than the first.
Looks like a situation for 'gusty rainfall' though it does have a bit of a 'squall line (ish)' signature on it.
BEYOND EARLY SUNDAY: Much cooler going into Tuesday through Thursday, after Sunday late morning as winds become westerly and gusty..cooler air is to follow though similar to recent days for a good stretch.
How cool remains in question, but some freezing temperatures north of I-4 are not totally out of the question as was the case just recently.
Further south from Cape Canaveral downward, much like what was just experienced and is being attested to this morning.