Nor'Easter 'Like' Conditions Could Put Big Damper On Coastal Weekend Plan

Latest Surface Plot with Radar Overlay from the SPC Mesoscale Analysis webpage plots shows a cold front approaching Pensacola with a High Pressure Ridge which extends NNE off the coast of New England and down the coast cutting across North Central Florida. The cold front will beach across the Big Bed by sunrise on Friday and clear the south end of the state near or shortly after sunset.

TODAY: Surface ridge crossing the state today with a moist shallow layer trapped below 5500 ft (bone dry above) under a subsidence inversion.  The upper level trough supporting the surface front will press East to ENE through tomorrow and off the Georgia Coast before Saturday, day break. Skies today to be partly sunny, with profound big breaks in the clouds for ample sunshine from time to time co-existing with other areas of nearly cloudy conditions as light ENE winds become more SE to S and work down the coast during the mid-late afternoon. By sunset light ESE-SE winds will have reached toward the Space Coast with continued ENE-E winds going ESE toward far South Florida. Clouds could break up a little more toward sunset as the trough approaches and breaks up the inversion, but timing is difficult to portend exactly when. Otherwise, non - consequential and pleasant conditions prevail with highs in the upper 70Fs to lower 80Fs with light winds, possibly variable toward sunset Central/South.

3pm visible satellite image today shows cotton patches over Florida induced by heating of the land mass (note the lack of clouds over the waters). Later today most of the clouds should dissipate with the exception of the Panhandle as the front will be entering that area and cotton pickers hit the fields.

TONIGHT/EARLY FRIDAY:  The front will continue to press eastward with overnight winds becoming SW at 12-20mph by daybreak or shortly thereafter. Overnight lows similar to the past two mornings, with much less warming behind the front during the afternoon across North Florida.


Increasing clouds with daybreak as well, with continued mostly cloudy conditions entering Central Florida and continuing until at least 3pm..possibly breaking up from NW to SE during the mid to late afternoon as clouds increase from South Central to South Florida. Some showers are possible south Florida, but if so, mainly sprinkles under the cloud deck.


FRIDAY NIGHT: Winds becoming WNW after frontal passage and veering to NW-NNW overnight at 10-18mph. Skies clearing from NW-SE. The overnight low from JAX to Sebastian Inlet will likely occur prior to 5AM with a more northerly wind becoming NNE shortly after day break


As noted previously, it looks like there will be a sharp temperature gradient between those along and east of A1A to those 40 miles away from the coast toward the west side of the state. Overnight lows in the western suburbs of Orlando could be in the upper 40Fs whereas   east of A1A at daybreak could be closer to the mid-upper 60Fs and warming to lower 70Fs shortly after sunrise. Very cool as far south as the southern tip of the state with lows in the mid 50Fs to lower 60Fs, co-existing with some upper 40Fs as far south as the NW side of Lake Okeechobee. Quick rebound in temperatures after 10AM everywhere.


SATURDAY: After a very cool start to the day, winds along the east coast from JAX to Ft. Pierce increase toward 15-22mph with gusts toward 28mph by early afternoon. It appears an extensive low level cloud deck will accompany these winds with some possible sprinkles under a very shallow but rather dense cloud deck which will exist approximately in the 3200 -6000ft layer. Stronger winds within the cloud deck then rapidly decreasing high up. This will be the theme through sunset with winds decreasing a few hours after dark.


BEYOND - WEEKEND RATIONALIZATION: It gets very sticky. The GFS/NAM/ECMWF are in General agreement with a few minor exceptions that make a major difference to the sensible weather across mainly the north 3/4 of the state from St. Augustine to Ft. Pierce. The NAM is much more aggressive with the wind and rain factor namely because it has the surface low that moves off the coast drop further south into the western Atlantic (well offshore by a few hundred miles) closer to the Florida East Coast than the GFS. It also continues to drop the low further SSE, whereas the GFS takes it further from shore and lingers it there for several days. The ECMWF seems to disregard this low all together as it swoops it ENE ward and well away, but in any case winds will remain elevated with a very long fetch from the NE-ENE from well out in the Atlantic.


Thus, big rip current threat and possibly a minor erosion threat for Flagler/Volusia if the NAM verifies. Should not be a problem for swimmers, unless one wants to swim under the clouds in choppy waters for some unknown reason.


The NAM really does look over done, especially in the instability department with the possibility of thunder  toward Volusia/Flagler overnight Saturday into Sunday. The NAM overplayed this storm system as it entered the Central Plains 36 hours ago, portraying some dreadful blizzard conditions and high snowfall totals that never happened in the forecast areas. Thus, sticking with the "NAM On Over Drive" Rationalization once again...until proven different. For instance, the NAM is driving 25-35mph winds into the East Coast from Port Canaveral and north, with measurable rainfall as well, with gusts just offshore to gale force. Some of this might have to do , though, with the sea surface temperatures, which from what I read else where will be sampled later today. Thus, expecting better model agreement heading into tomorrow with a little time to spare before Saturday evening remaining.


WEEKEND FIRST GUESS: In going with the GFS, which has been most consistent: mostly cloudy near the coast with some light sprinkles only at the beaches. Surface winds are show per streamline analysis to be diffluent at the low levels under substantial drying above 8 000 ft which would account for the lack of measurable rainfall (at least, within a three hour time frame).  Winds pick up interior inland during the afternoon and die off at night. Another cool start Sunday inland and west side toward the SW Side of Lake Okeechobee, but coastal lows along A1A up and down the coast remain near 70F or more .  Winds pick up again Sunday afternoon and spread cloudiness inland with coastal sprinkles.


No matter which model verifies, things do not look all so great for the big Air Show along the Space Coast this weekend. Less than stellar to be more fair. From an aviation perspective, there could be moderate turbulence along the top of the cloud deck, not to mention the lower clouds obscuring a solid view of an flying vehicle for any sustained time frame. Not unlike watching the STS Missions launching into the clouds for a full 20 seconds of viewing time.


STRESSING: The much more subdued reasoning hinges on riding with the GFS positioning and strength of the high and low pressure couplets. If the NAM verifies, it will be a full bore N'oreaster , with erosion becoming a concern as well. Chances are, the truth will be somewhere in between the two models, with some measurable rainfall mainly along to north of the Beachline toward Vero, with better chances along coastal Volusia/Flagler.


MONDAY/TUESDAY: More of the same with gradually decreasing winds. Inverted trough is shown along the coast on Monday, which breaks down around 11AM allowing sprinkles and clouds to work across the state. A repeat performance of less coverage is possible on Tuesday. Coastal lows and highs remain in the lower to mid 70Fs under the cloud deck, with inland lows warming each morning after Sunday.


Conditions break down much like they are doing so today around Thursday with another front very close to where to the one of today is located on Thursday morning. This front will behave in similar fashion to that of tomorrow's, although there are indications it could drop some rain during its passage. No big temperature changes.


EXTENDED: Watching the Caribbean as well as an area near the Eastern Bahamas, perhaps as soon as mid-week next week, but no land threats appear in the verge of comprehension of a tropical like system...at least not for the contingent 48 states.