[MCD] SWOMCD

Tue Dec 19 05:48:44 UTC 2006

ACUS11 KWNS 190549
SWOMCD
SPC MCD 190548 
TXZ000-OKZ000-KSZ000-NMZ000-191015-

MESOSCALE DISCUSSION 2277
NWS STORM PREDICTION CENTER NORMAN OK
1148 PM CST MON DEC 18 2006

AREAS AFFECTED...TX AND OK PANHANDLES...EXTREME E-CNTRL NM

CONCERNING...WINTER MIXED PRECIPITATION 

VALID 190548Z - 191015Z

SHOWERS/ISOLATED TSTMS OF FREEZING RAIN MIXED WITH SLEET WILL
CONTINUE ACROSS THE TX/OK PANHANDLES THROUGH 12Z. ICE ACCUMULATIONS
SHOULD GENERALLY REACH .05 IN/HR WITHIN MOST SHOWERS. HOWEVER...A
MORE INTENSE/CONCENTRATED AREA OF FREEZING RAIN MAY DEVELOP FROM
AROUND 50 W PVW TO AMA TO 50 SE GUY. JUST SE OF THIS LINE...STRONGLY
FOCUSED LOW-LEVEL WARM/MOIST ADVECTION WILL BE MAXIMIZED THROUGH THE
OVERNIGHT HOURS. IN ADDITION...WEAK ELEVATED INSTABILITY...EVIDENCED
BY RECENT CG LIGHTNING STRIKES...WILL AID IN PRODUCING ICE
ACCUMULATION RATES AROUND .10 IN/HR AT TIMES.

05Z SURFACE ANALYSIS PLACES THE FREEZING LINE FROM ABOUT 60 W LBB
NNEWD TO 10 S AMA TO LBL. LOW-LEVEL TEMPERATURES WILL COOL FURTHER
MAINLY ACROSS THE NRN TX AND OK PANHANDLES AS SURFACE
TEMPERATURE/DEW POINT SPREADS REMAIN AROUND 10 TO 20 DEGREES. PER
00Z AMA/MAF AND 03Z LBB OBSERVED SOUNDINGS...LARGE WARM NOSE OF
ABOVE FREEZING TEMPERATURES EXISTS BETWEEN 750-850 MB ATOP THE
SURFACE-BASED COLD DOME. 00Z MODEL GUIDANCE IS VERY CONSISTENT IN
MAINTAINING THIS STRUCTURE OVERNIGHT WITH 25 TO 35 KTS OF SELY FLOW
FEEDING INTO A SSW TO NNE ORIENTED 800 MB STATIONARY FRONT. THIS
WILL RESULT IN FOCUSED LOW-LEVEL WARM/MOIST ADVECTION ABOVE THE
COLDER NEAR-SURFACE LAYER. 03Z RUC/00Z NAM FORECAST SOUNDINGS
INDICATE FREEZING RAIN WILL BE THE PRIMARY PTYPE. SLEET
WILL BE MORE PREVALENT FURTHER NW FROM TCC TO DHT TO LBL WHERE THE
WARM NOSE WILL REMAIN COOLER THAN 2 TO 3 DEG C.

..GRAMS.. 12/19/2006

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

...NOTICE...
SPC WINTER WEATHER MESOSCALE DISCUSSIONS WILL BE ISSUED ON A
SCHEDULED BASIS FROM DECEMBER 1 THROUGH FEBRUARY 28...FOUR
TIMES A DAY...AROUND 00 UTC...06 UTC...12 UTC...AND 18 UTC
FOR SIGNIFICANT SHORT RANGE WINTER WEATHER EVENTS.

ATTN...WFO...DDC...LUB...AMA...ABQ...

37190033 36520004 35250103 34350199 33930276 33750339
34290361 35120337 36360239 37050157 37220104 

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