"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".

Tuesday, January 18, 2011

Little Change Through Early Thursday - Pleasant Temperaturess

Images: Forecast for 2pm EST today. Note low pressure near the mid-Atlantic coast (Florida's storm yesterday), very weak low in eastern Gulf, an obvious cold front near the Mississippi River (hint: no worries here from that one), and more importantly low pressure over the Desert SW region (remember that area).

NOW: Strong but very shallow inversion on local and surrounding atmospheric samples (soundings) showed up nicely at 800 ft. this morning as noted in the supplied image above by the green arrow I've drawn on the image. Near full saturation below the inversion and mixing due to stronger mid-upper level wind just above this shallow/moist layer is responsible for wide spread low cloud ceilings and fog across the state early which is rapidly breaking up as I write.

SYNOPSIS: As provided, we see the low pressure area that finally crossed the state during the evening and exited just north of Daytona Beach is working up the eastern seaboard. This low is being energized by an air mass of Pacific and Subtropical origins (as opposed to last week's system which was of Subtropical and Arctic origin which eventually made it cold in Florida and snowy in the NE). Net result is that the mid-Atlantic is receiving rain near the coast (instead of snow) and a mixed bag of precip (precipitation) near the coast further north as the atmospheric temperature profile of the atmospheric attempts to adjust to the changing temperatures overhead. Humorously, one location where all the mixing of precipitation types was occurring reported "precipitation of unknown origin' this morning, funny.

Now that the system has cleared Florida, there does remain a very weak low in the Gulf as pictured with a weak boundary (the former warm front) drapped across North-Central Florida which weakly joins at the hip with the system moving up the coast. The 'warm front' has wrapped around the low pressure system's north side bringing just warm enough conditions to turn sleet to rain as the mixture of Pacific and Subtropical air tries to undercut and/or over-run the area up there that has been cold and experienced recent snows.

We also observe from the satellite image that around the low itself in the Gulf there is very little cloud cover, yet some light rain showers have come ashore Florida's west coast between Yankeetown and Crystal river and are passing somewhere between Gainesville and Ocala. This is an indicator of the boundary's presence (that I've sketched in) as well as the low pressure area (benign as they may be). It's unlikely you'll see these features on TV.

Cloud cover/fog over the peninsula is rapidly breaking up, so I do believe that the majority of the afternoon will remain partly cloudy (perhaps very briefly mostly cloudy at times once any heating in cloud breaks abets in supplying subsequent additional cloud formation) with all the low level moisture remaining in place and strong sunshine; otherwise, cloud breaks or sustained sunshine will permit afternoon high temperatures to reach the low-mid 70s and mid-upper 70s further south, maybe even an 80F or two far south.

WSW-SW wind all day with no rain chances Central (beyond those scant few further north), and perhaps a few showers far SE near Miami Metro. The boundary across Florida will remain there through Wednesday afternoon until a kicker (the cold front shown) absorbs whatever is left of the low as that front pushes east and lifts north simultaneously.

TONIGHT-WEDNESDAY: Little change with low clouds/fog again possible overnight with comfy temps. Low of 55F-60F, and another day of high temperatures close to today's. Continued light west wind and partly cloudy by noon.

WEDNESDAY AFTERNOON/EVENING: Front shown in the image passes mainly to the north as the supporting upper level trough located just along/off the U.S. East coast relaxes (looses its southward extent). In doing so, the chances for fog and low clouds Wednesday morning does not look as good, but this could change. Otherwise, no big temperature changes or rain, although it bay be a bit cooler early Thursday morning inland minus the inversion and overnight cloud cover.

THURSDAY: Remember now the low pressure area in the Desert Southwest. This will be our next local trouble maker beginning daybreak Thursday but of greater worthiness of note all day Friday. Mild again Thursday morning, with a scant chance of a coastal drip but no big deal just about any time. Partly cloudy with a light southeast wind gradually veering to SSE by day's end. Coastal temps the coolest in the afternoon with the now onshore component wind established, but warmer away from the coast and South Florida. Continued mild overnight, especially as I'm expecting a better chance of cloud cover to develop in the already never fully dried out airmass over the state (at least not for long enough for the environment from recovering fairly rapidly).

The system in the Desert Southwest will be gathering moment as it joins forces with a system of Pacific origin and is forced eastward across the East/Central Plains and Deep South. The front enters the far western Florida Panhandle overnight Thursday into Friday.

FRIDAY: Expecting that at day break, the front will be located across the Florida Panhandle with lots-o-clouds over much of the state in varying degrees and heights, particularly Central and North Florida. Rains over the Panhandle and perhaps some rumbles of thunder. Rain chances and prolific cloud cover increase across the state during the day, again namely North and Central. Big rainfall totals not anticipated nor is severe weather, although some thunder is possible. Perhaps a 40% overall coverage a measurable rain once all is said and done between sunrise-sunset. Front could be located roughly across the Central Peninsula at sunset, and crossing all but extreme South Florida overnight with drier/much cooler air to follow. Probably not as warm on Friday as today-Thursday due to cloud cover. Mainly mid-upper 60s, cooler north and, as usual, warmer south from West Palm Beach to across Lake Okeechobee toward Ft. Myers.

SATURDAY: Very cool day finally (not that this is a good thing) gets here after having our nice break from the cold. But not too bad nor for very long. Yeah! Saturday appears at this time will be the coldest of the weekend from sunrise to sunset with lows by morning in the low-upper 40s, warmest East Central and South, coldest Interior Central/North/and West toward Punta Gorda due to the fact that the wind will be quick behind the boundary to acquire a NW-NNW wind component, sparing the Barrier Islands from the worst of it for Central and the gradually weakening evolution of cold air infringement farther south and east from West Palm to Miami especially in regards to morning lows down that way. But it will remain very cool Saturday afternoon with highs in the low-mid 60s, mid-upper 60s south. Most cool north of 520 and points north with a NW-NNW wind of 15-20mph during peak heating.

SATURDAY NIGHT: Another sort of cold morning inland, but local outlets (such as Orlando channels) will advertise it being colder than the Barrier Island counterparts will feel. Like our last system, the first to warm will be from Cape Canaveral south along the A1A corridor as winds swing around to onshore overnight toward sunrise Sunday.

SUNDAY: Milder morning at the immediate coast with a low closer to 50-52F, perhaps an upper 40 especially north of Satellite Beach..with continued a bit chillier along and west of US1. Afternoon to warm by a good 5F degrees by afternoon.

BEYOND: The ever changing Magic Eight Ball this go around upon a shake, reads, "A word of the wises, be prepared for surprises (around Tuesday)". It might be seeing an evolution of events to unfold much like what occurred yesterday across Florida (and as last night's GFS hints at). Too soon to say...

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