"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, November 21, 2011

Thanksgiving Weekend Round One- Showers Today

IMAGE: Mid Morning surface temperatures are shown. Note the 70F degree isotherm. It is along and south of that line, in general, that the best chance of showers should exist today. The area in light blue is where measurable rainfall totals appears to be  possible, but not solely inclusive. However, even those chances look pretty slim, with coverage likely being restricted to a few locations (again, if any) by early afternoon through dusk.

TODAY: Surface high pressure just off/near the coast of Georgia/South Carolina and in the mid-levels almost directly over the state of Florida today is making for weak steering currents with low to mid- topped showers  moving from the east to ESE toward the west to WNW. All model guidance this hour is showing for some pretty good rainfall across the Southern Half of the state..or rather..some moderate rainfall in showers  with truly measurable amounts without having to bat an eyelash in doubt. 

However, that has been the case in the short term models for the past few days with not nearly the coverage depicted..nor where it was expected. Given the trends of morning radar/satellite loops I suspect they are again over-playing today's wet spots so taking the broad brush approach as shown in the above image for favorable coverage areas. Outside of those rain chances, the winds have noticeably dropped off, which sure is nice change.

 Net result will be a warmer day along the east coast and likely interior outside of the clouded over areas, with highs in the low 80Fs and possibly some mid-80Fs interior areas South 1/2 of state. Low 80Fs north.

TONIGHT/TUESDAY/EARLY WEDNESDAY: Very light wind and rain chances ending as the sun approaches the west horizon with nightfall. Near calm wind tonight with a shallow low level inversion under mostly clear skies should be able to set up for respectable 'fog spots' almost anywhere with good radiational cooling , especially the north half of the state.

Tuesday looks to be a dry one with comfortable temperatures running again close to those of today, but with warmer temps running the across the entire state by afternoon. Light winds not worth mention.

Wednesday again has a chance of early morning fog/mist, especially South. This was noted as a possibility nearly 5 days ago if not more and continues to be the case. Very cool morning for east coasters with a west wind (very light). This will mean "no sea breeze, land breeze instead" and thus no warm ocean water air being pushed ashore. Lows in the lower-mid 60Fs as opposed to the lower 70Fs that were felt along the east coast of Brevard and South this morning. Lower 60Fs seems to be the prevalent mode in the morning (widespread), but warming into the mid-80Fs over a broad expanse as a cold front will be moving across the Panhandle early in the day with some showers/thunder possible there. There is a front on the approach, and temperatures Wednesday morning might actually be cooler AHEAD of the front than behind the front (in the mornings).

THANKSGIVING EVE/THANKSGIVING: Cold front timing of course is always a player this time of year in the wind/rain/temperature fields (i.e., weather).  Like the previous front, this one appears to go through mainly dry for  Central and maybe even North Central this go around..and mainly overnight with some clouds. Front will be moving across North Central  after midnight toward sunrise and should clear the CDL (Central Dividing Line) close to sunrise, followed by NW winds gradually veering to north to NNE by day's end. The boundary could be playing through the South Half of the state most of Thanksgiving Day, with a better chance of showers along a line from Vero Beach - Sarasota and south. Comfortable temperatures even behind the front but becoming breezy toward the east side by mid-late afternoon as a wind surge moves in. Chances are this will be accompanied by cloud cover. All in all, averaged over the years, this looks to be a very "average Thanksgiving" for most of the state other than the south half. Previous Thanksgivings have varied to very very warm to Severe Weather, but mostly are uneventful.   

This front looks like it will have very little impact on the temperature fields worth mention. Temperatures return to those experienced the past few days (with today - Wednesday being warmer), with similar wind as well, stronger for a day or two from the NE-ENE-E after frontal passage.

EXTENDED THANKSGIVING WEEKEND: Looks similar to the  previous post of a few days ago: Another front will break the "one front a week rule" of the past month or so, with an arrival at the End of Thanksgiving Day weekend or roughly 4 days later. It is possible this low pressure system/front could entrain moisture from the tropical Pacific, with a steadfast surface to mid-level low to develop over the area around North Georgia with time. Timing would place the boundary through late Sunday..and it's not pretty.

As noted previously, this second evil twin front could be an introduction to the formal onset of Florida Winter almost right on cue with December 1 except it would be around the 28th of November. Overnight lows do not look terribly cold; it is the amount of dry air and very cool afternoon highs that will be the bigger impact if all goes according to "Plan". 

The front also appears to have a better potential to be a 'wet' one...with possibly preliminary rain/showers impacts as well as opposed to only with the front proper.  All in all, experience says that once a pattern is broken this time of year it could be a longer duration break from previous experiences in the same period/time frame. Thus, overnight low and day time highs might never fully recover to those we've had the past week or so.  This boundary could also lower the water temperatures along the near shore Atlantic which would mean that the next time we have onshore winds they will be cooler from previous periods of long duration easterlies. 

Still too early at this stage of the game to set the extended  down in concrete...  all could change in a flash.  At least we have a head's up, not to be worse for wear.

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