[MCD] SWOMCD

Fri Jan 19 19:01:09 UTC 2007

ACUS11 KWNS 191903
SWOMCD
SPC MCD 191903 
TXZ000-NMZ000-200000-

MESOSCALE DISCUSSION 0083
NWS STORM PREDICTION CENTER NORMAN OK
0103 PM CST FRI JAN 19 2007

AREAS AFFECTED...CAPROCK/SOUTH PLAINS OF WEST TX AND EASTERN NM

CONCERNING...WINTER MIXED PRECIPITATION 

VALID 191903Z - 200000Z

A MIX OF SLEET AND SOME FREEZING RAIN IS EXPECTED TO DEVELOP
NORTHWARD AND INCREASE ACROSS THE WEST TX PLAINS/CAPROCK VICINITY
THROUGH THE AFTERNOON...INCLUDING THE LUBBOCK AND PLAINVIEW
AREAS...WITH SNOW BECOMING MORE PREDOMINANT BY LATE AFTERNOON.
MAINLY SNOW WILL BECOME INCREASINGLY HEAVY ACROSS EAST CENTRAL
NM...WHERE SNOW RATES COULD REACH 1 IN/HR AFTER 21Z.

WATER VAPOR IMAGERY AND UPPER AIR DIAGNOSTICS FEATURE A CLOSED UPPER
LOW CENTERED NEAR NORTHERN BAJA MEXICO...WITH A DEEP PACIFIC
MOISTURE PLUME EXTENDING ACROSS NORTHERN MEXICO INTO NM AND THE
ADJACENT SOUTHERN PLAINS. OBSERVATIONAL TRENDS AND LATEST NAM/RUC
AND 4KM WRF NMM/NSSL GUIDANCE SUPPORTS A NORTHWARD
EXPANSION/INCREASE OF WINTER MIXED PRECIPITATION ACROSS NORTHWEST TX
THIS AFTERNOON. WHILE LOW LEVEL DRY AIR WILL INITIALLY DETER HEAVY
PRECIPITATION DEVELOPMENT WITH NORTH EXTENT ACROSS THE TX
PANHANDLE...AND LOW LEVEL TEMPERATURE PROFILES HAVE GENERALLY BEEN
MARGINAL AROUND FREEZING ACROSS WEST TX...HIGHER PRECIPITATION
RATES/EVAPORATIVE COOLING HAVE BEEN SUFFICIENT TO BRING TEMPERATURES
DOWN TO BELOW 32F AMIDST MIXED PRECIPITATION. A MIX OF SLEET/LIGHT
FREEZING RAIN HAS BEEN COMMON OVER THE PAST FEW HOURS IN
OBSERVATIONS AT LUBBOCK TX/CLOVIS NM.

WITH LARGE SCALE FORCING FOR ASCENT INCREASING THIS AFTERNOON...A
SPECIAL 15Z OBSERVED RAOB FROM REESE CENTER /JUST WEST OF LUBBOCK/
SUPPORTS A MAINTENANCE OF MAINLY SLEET/SOME FREEZING RAIN THROUGH AT
LEAST EARLY AFTERNOON PER THE PARTIAL MELTING LAYER OBSERVED BETWEEN
750-825 MB. OF NOTE...BASED ON THE OBSERVED REESE SOUNDING DATA...IT
APPEARS THE 12Z NAM/GFS POINT SOUNDINGS MAY BE EXHIBITING A FEW
DEGREE COOL BIAS WITHIN THE ELEVATED WARM LAYER.
RUC/NAM FORECAST SOUNDINGS ULTIMATELY SUPPORT SNOW BECOMING MORE
PREDOMINANT ACROSS NORTHWEST TX BY LATE AFTERNOON.

ACROSS EAST CENTRAL NM...VERTICAL PROFILES APPEAR MORE FAVORABLE FOR
SNOW AS THE PREDOMINANT PRECIPITATION TYPE...ESPECIALLY FROM CLOVIS
WESTWARD. OBSERVATIONAL TRENDS/NUMERICAL GUIDANCE SUGGEST SNOW RATES
COULD REACH 1 IN/HR AFTER 21Z ACROSS EAST CENTRAL NM...INCLUDING THE
CLOVIS/FORT SUMNER AREAS TO NEAR/JUST SOUTH OF I-40.

..GUYER.. 01/19/2007

...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...LUB...AMA...MAF...ABQ...EPZ...

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