[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 251252
SWOMCD
SPC MCD 251252 
ALZ000-FLZ000-MSZ000-LAZ000-251745-

MESOSCALE DISCUSSION 2576
NWS STORM PREDICTION CENTER NORMAN OK
0652 AM CST SAT DEC 25 2004

AREAS AFFECTED...SERN LA/SRN MS/EXTREME SW AL

CONCERNING...WINTER MIXED PRECIPITATION 

VALID 251252Z - 251745Z

...POTENTIAL FOR SNOW/SLEET/FZRA ACROSS PORTIONS OF SERN LA INTO SRN
MS...

VIGOROUS UPPER LOW IS NOW MOVING NEWD AWAY FROM SERN TX COAST...WITH
THE HEAVIEST SNOW JUST ABOUT ENDED ACROSS THE TX MIDDLE COASTAL
PLAIN WHERE RECORD AMOUNTS OF SNOW FELL OVERNIGHT. MAIN PRECIP BAND
HAS REMAINED OFFSHORE...LIMITING SIGNIFICANT AMOUNTS OF SLEET/SNOW
TO SRN LA THUS FAR. 

12Z OBSERVED SOUNDING AT LCH SHOWS SIGNIFICANT DRY LAYER FROM THE
SFC-800MB. IF THE ETA/RUC QPF FORECASTS ARE CORRECT...THEN THE
HEAVIEST PRECIP WILL REMAIN OFFSHORE LIMITING POTENTIAL FOR HEAVY
SNOW OR EVEN ICE ACCUMULATION FARTHER INLAND. HOWEVER...UPPER LOW IS
STILL WINDING UP AS IT EXITS S TX...AND RECENT RADAR IMAGERY
SUGGESTS THAT BAND OF HEAVIER PRECIP EXTENDING FROM VERMILLION BAY
SWWD WILL TRANSLATE INTO SRN LA OR THAT ANOTHER BAND WILL EVOLVE.
TEMPERATURE FORECASTS AT 850MB WILL MAINLY BE ABOVE FREEZING ACROSS
THE DISCUSSION AREA WHICH WOULD LIMIT SNOW POTENTIAL. 

CURRENT SFC TEMPS ARE AT OR BELOW FREEZING ACROSS MOST OF THE
DISCUSSION AREA...AND WITH LOW DEWPOINTS AND WET BULB TEMPS HOVERING
JUST BELOW FREEZING...SFC TEMPERATURES ARE NOT LIKELY TO RISE
MUCH...SO FZRA IS A DEFINITE CONCERN. IF STRONG DYNAMIC COOLING CAN
ERODE THE WARMER AIR JUST ABOVE THE SFC...A BAND OF HEAVIER
SNOW/SLEET COULD DEVELOP NEAR PTN/MOB PARTICULARLY AFTER 18Z AS
DEPICTED BY THE LATEST RUC FORECAST SOUNDINGS/PTYPE.

..TAYLOR.. 12/25/2004

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

...NOTICE...
SPC WINTER WEATHER MESOSCALE DISCUSSIONS WILL BE ISSUED ON A 
SCHEDULED BASIS...FOUR TIMES A DAY...BETWEEN 00-01 UTC...
06-07 UTC...12-13 UTC...AND 18-19 UTC AS SIGNIFICANT SHORT
RANGE WINTER WEATHER EVENTS UNFOLD.  THIS SCHEDULE WILL BE
USED FROM DECEMBER 1 THROUGH FEBRUARY 28.

ATTN...WFO...MOB...JAN...LIX...LCH...

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