"But seeing they could not See; hearing they could not Hear"
“The views expressed herein are those of the author and do not necessarily represent those of the National Weather Service or affiliate/related organizations. Please consult .gov sites for official information”

"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 28, 2011

A Prelude to Winter Begins Tonight

Mid-Morning position of Surface Cold Front and weak pre-frontal trough in the Eastern Gulf of Mexico (GOM). Both will tandem to the east, with the leading edge of   reaching the Central Interior during early to mid-afternoon, then east of I-95 toward 4pm and thereafter into the evening hours.
Wind barbs and fronts alone do not provide the mental image we need to envision what the boundaries will mean when looking outside. The vehicle to provide a future reference point is the visible satellite image. The fronts have been recreated here for reference....the green shows how the band of showers and rain are aligned with the front, so timing from this can be extrapolated eastward with time. With some daytime heating expect to see more clouds anywhere , but the will not be of much consequence until at least early afternoon toward Orlando (as a reference point), but will spread to the immediate coast after 3pm or so. Showers as well. Note the extent of cloud cover behind the cold front over the Gulf yet to come well after the front has moved east of the Florida Peninsula.

Lastly, from a broader perspective, we can observe here that the surface features are contained within a 3 dimensional entirety , consisting of this mid-level low pressure system well as an upper level low (not shown here). 

Within the mid-levels toward 8500 feet overhead resides a deepening low pressure area. The 'spokes' in light blue represent for presentation purposes only of further discussion below how there will be three fronts to move across the state today through Wednesday evening. Each passage will evoke a slowly drying atmospheric moisture profile throughout the columns in the vertical, with the second and third spokes being the primary contributors within that process.  

TODAY: Wheels in the sky keep on turning, and today's is rolling across the Southern Mississippi River Valley Region and the Deep South  with more than one attendant surface low. The surface to mid level lows as shown in the above are both contained within the Mother Load..the upper atmosphere. The mid-upper levels are almost stacked overtop each other. As history tells us, that means slow progression of the ensemble as a whole, so it will be with us through the remainder of the week in various forms. Possible rain rain impacts are the first and foremost variable of interest since they  will be first realized.

SSE-S winds today at 10-20mph with gusts to 25+ perhaps over the waterways. Partly cloudy skies earlier with cloudier conditions spreading toward the east from the west coast during late morning and into the afternoon. Timing of features per close model agreement places showers/rain near  Orlando (and north) around 2-3pm and on the immediate east coast in the  5pm time frame. 

Not everyone will see showers today, especially locals who live toward the east side of the state along and south of the north side of Lake Okeechobee. Thunder is not expected, although a few rumbles are not entirely zero'd out ...just highly unlikely.  The atmosphere is neutral enough in the instability parameter such that it would not be an issue. 

The main impacts are cloudy skies, breezy, and showers from late afternoon through 8pm or so in the area north of the less likely area to the south. Winds will become SW-W-WNW shortly before, during, and after passage of the two boundaries...which will clear the entire state after midnight ..apparently most definite prior to sunrise all locations.

TUESDAY: Mainly West winds at 10-18mph G 22. Partly cloudy after a morning low in the lower 60Fs far east to mid-50Fs interior. Cooler tomorrow with highs in the upper 60Fs to lower 70Fs South Florida. In all cases, cooler north of I-4.

WEDNESDAY: The second boundary/front will be moving through late in the day after another cool start in the 50Fs and low/mid 60Fs. This will be the first influx of truly (noticeably) drier air. Passage of this boundary will take the winds toward a definitive NW direction over night with falling temperatures to a greater degree as the drier air moves in.

THURSDAY: The second boundary now  having cleared the state with much drier air (lower dew points). Lows in the low 50Fs to upper 40Fs many areas except the far north (colder), and south (warmer). Very cool Thursday afternoon with highs in the mid-upper 60Fs with much clearer skies by now if not sooner on Wednesday. Hoping for 70Fs though, which is not out of the question.

FRIDAY: Round -the- wheel goes as it lifts toward the eastern Great lakes. The final front will have to approach from a much more northerly directory, with N-NNE winds to follow during the afternoon. Timing will have to be re-adjusted in regard to exactly when this will occur. Some clouds associated with this feature, followed by a warming trend through the weekend to seasonal norms.  

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