Winter Storm and Winter Weather in Texas, February 12, 2012

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LUBBOCK TX
523 AM CST SUN FEB 12 2012

.AVIATION...
BKN-OVC VFR TO MVFR CLOUD DECKS PERSISTED ACROSS KCDS AND KLBB
RESPECTIVELY EARLY THIS MORNING. THIS TREND WILL CONTINUE UNTIL
THIS AFTERNOON AS DETERIORATING CONDITIONS ENSUES FROM WEST TO EAST
THANKS TO AN APPROACHING WINTER STORM SYSTEM. CLOUD DECKS WILL
DROP TO IFR CRITERIA AT KLBB LATE THIS AFTERNOON AS -SN COMMENCES.
BY 12/00Z...BOTH KLBB AND KCDS WILL BE EXPERIENCING IFR CLOUD
DECKS AND MIXED PRECIP AT KLBB /-SNPL/ WITH -SN MORE LIKELY AT
KCDS. TOWARDS THE END OF THE TAF PERIOD...BOTH SITES WILL
EXPERIENCE MIXED PRECIP /-FZRAPL/ WITH BETTER CHANCES MORE SO AT
KCDS AS PRECIP BEGINS TO SHIFT EAST. THUS LIFR CLOUD DECKS WILL
BE POSSIBLE TOWARDS THE END OF THE TAF PERIOD.

&&

.PREV DISCUSSION... /ISSUED 339 AM CST SUN FEB 12 2012/

SHORT TERM...
MAIN CONCERN FOR THE SHORT TERM PERIOD IS THE ANTICIPATED WINTRY
WEATHER...CAUSED BY AN UA LOW MOVING EAST ACROSS THE DESERT
SOUTHWEST.

A RATHER CHILLY AND DRY AIRMASS IS IN PLACE ACROSS THE SOUTHERN
PLAINS EARLY THIS MORNING...AS TEMPS WERE IN THE TEENS AND 20S AND
DEWPOINTS WERE NEARING/EQUATING SINGLE DIGITS PER 09Z METAR
ANALYSIS. EASTERLY/UPSLOPE SFC WINDS HAVE BEEN PREVAILING FOR OVER
24 HOURS AND THUS INDUCED OVERCAST CLOUD DECKS OF 2000-4000 FT. THE
WINTER STORM OF INTEREST WAS SPATIAL DISTRIBUTED ACROSS NORTHWESTERN
ARIZONA/SOUTHWESTERN NEVADA AS A CLOSED LOW SYSTEM. HOWEVER FORECAST
MODELS AGREE THAT THE SYSTEM WILL OPEN INTO A WAVE-LIKE FEATURE AS
IT NEARS THE REGION AND TRANSLATE NE TO ACROSS THE CENTRAL PLAINS BY
THE END OF THE SHORT TERM PERIOD. OPEN WAVES TYPICALLY DO NOT CREATE
SIGNIFICANT ACCUMULATING SNOWFALL...HOWEVER THIS SYSTEM AND STORM
TRAJECTORY IS NOTEWORTHY TO ALLOW WINTER WEATHER ADVISORY SNOWFALL
AMOUNTS /1-2 INCHES/ TO ENSUE.

WITH RATHER DRY SFC CONDITIONS...THE FIRST THING THAT NEEDS TO OCCUR
IN ORDER FOR PRECIP TO REACH THE GROUND IS A TOP-DOWN MOISTENING
WHICH MODEL SOUNDINGS DO INDEED EXHIBIT. THIS WILL TRANSPIRE FROM
WEST TO EAST AS LARGE SCALE ASCENT OVERSPREADS THE REGION. THE
FOLLOWING IS THE EXPECTED TEMPORAL AND SPATIAL DISTRIBUTION OF THE
WINTRY PRECIP. PRECIP WILL COMMENCE ACROSS THE TEXAS/NEW MEXICO
BORDER BY 15-18Z. WITH BKN-OVC CLOUDS BEING A DOMINATING FEATURE
THROUGHOUT THE EVENT...DAY TIME TEMPS WILL STRUGGLE TO REACH/EXCEED
FREEZING /UPPER 20S NW TO LOWER 30S SE/. THUS...SOUNDING PROFILES
SUGGEST BELOW FREEZING TEMPS ALOFT AS WELL AND HENCE PWATS NEARING
0.60 INCHES...MOISTENING PROFILES AND PARTICULARLY DECENT MOISTENING
WITHIN THE DENDRITIC ZONES SUGGESTS SNOW WILL BE THE DOMINATE PRECIP
TYPE ACROSS THE WESTERN LOCALES DURING THE AFOREMENTIONED
TIME-FRAME. BY 18-00Z...THE SYSTEM IS PROGGED TO BE NW OF THE
FOUR-CORNERS REGION...AND SYNOPTIC LIFT WILL BEGIN TO INTRUDE THE
REMAINDER OF THE CWA. WHAT IS OF NOTE TO MENTION DURING THE 18-00Z
TIME-FRAME IS THAT THE SFC RIDGE INITIALLY NE OF THE REGION WILL
SHIFT WELL EAST OF THE CWA AS SFC LEE TROUGHING BECOMES ESTABLISHED
NW OF THE CWA. THUS...SFC WINDS WILL VEER TO A MORE SOUTHERLY
COMPONENT. AS A RESULT...IT IS NOT SURPRISING TO SEE MODEL SOUNDINGS
INDICATING AN 850-750 MB WARM NOSE ACROSS ALL BUT THE SOUTHEASTERN
TEXAS PANHANDLE/NORTHEASTERN SOUTH PLAINS. THIS WOULD INDICATE THAT
THE LATTER AREA WILL BE ALL SNOW BUT THE FORMER AREAS WILL
EXPERIENCE MORE OF A SNOW/FREEZING RAIN/SLEET MIX. THE PROGGED WARM
NOSE ACROSS THE CENTRAL AND SERN ZONES DOES NOT APPEAR OVERLY
PREVALENT AS COMPARED TO THE WESTERN LOCALES...BUT STILL ENOUGH TO
WARRANT A SNOW/SLEET MIX.

BY 00-06Z...THE SYSTEM IS APPROACHING THE CENTRAL PLAINS AND BEST
POPS WILL SHIFT EAST. THE WARM NOSE BECOMES MORE PREVALENT ACROSS
THE WESTERN LOCALES AS SFC WINDS VEER TO A SLIGHT SOUTHWEST
COMPONENT. THUS...BOTH THE NAM AND GFS WANT TO DISPLAY DRY-SLOTTING
ESPECIALLY ACROSS THE SOUTHWESTERN TEXAS PANHANDLE BY 06Z. THE ECMWF
IS 6 HOURS SLOWER IN SHOWING A DRY-SLOTTING OCCURRENCE. WILL NOT
DROP POPS BELOW MENTION BUT WILL MAINTAIN CHANCE POPS ACROSS THE
SAID AREA AS PWATS OF 0.40-0.50 INCHES VALIDATES SO. THE MORE
SIGNIFICANT WARM NOSE SUGGESTS THAT A FREEZING RAIN/SLEET MIX IS
POSSIBLE. MIXED PRECIP ACROSS THE CENTRAL AND SERN ZONES APPEARS
VALID BUT CHANCES FOR SNOW MAY CONTINUE AS SYNOPTIC LIFT STILL
APPEARS ADEQUATE. AN ALL SNOW PROFILE ACROSS THE NE PREVAILS.
FINALLY BY 06-12Z...THE NAM...GFS AND ECMWF SOLUTIONS DISPLAYS
DRY-SLOTTING BECOMING A MORE DOMINATE FACTOR /MORE SO BY 12Z/ FROM
WEST TO EAST. ALL SOUNDING PROFILES SHOW A PREVALENT WARM
NOSE...ESPECIALLY OFF THE CAPROCK WHERE LEADING TO THE POSSIBILITY
OF A RAIN/FREEZING RAIN/SLEET TYPE PRECIP. SOUNDINGS ACROSS LOCALES
ON THE CAPROCK IS MORE OF A FREEZING RAIN/SLEET TYPE
PROFILE...ALTHOUGH POPS WILL DROP TO THE SLIGHT CHANCE CAT. TOTAL
SNOWFALL AMOUNTS OF 1 TO 2 INCHES WITH LOCALIZED 3 INCHES WILL BE
POSSIBLE. TOTAL ICE ACCUMULATIONS OF 0.05-0.1 INCHES WILL ALSO BE
PROBABLE AND THUS A WINTER WEATHER ADVISORY REMAINS IN EFFECT
THROUGH MONDAY 12Z.

LONG TERM...
GENERALLY QUIET WEATHER EXPECTED ON THE BACKSIDE OF THE TROUGH
THAT WILL BRING THE WINTRY PRECIPITATION TO THE AREA TODAY. BREEZY
WEST WINDS TO CONTRIBUTE TO WARMING MONDAY. LIGHTER WINDS TUESDAY
BUT WARMER AIR MASS TO REMAIN ACROSS THE AREA. POSSIBLE EXCEPTION
IS THE NERN ZONES WHERE THE NAM SUGGESTS SWRN EDGE OF COLD AIR
MASS ANCHORED OVER THE MIDWEST MAY BE A BIT STUBBORN TO LEAVE. THE
NEXT UPPER TROUGH PROGGED TO MOVE ONTO THE CNTL HIGH PLAINS
WEDNESDAY SHOULD HELP DRIVE ANY LINGERING COLD AIR EWD WITH BREEZY
WEST WINDS LIKELY DEVELOPING GIVEN THIS LOWS FURTHER NORTH
POSITION. WILL THEN LOOK TO LATE WEEK FOR THE NEXT UPPER LOW.
HOWEVER MODELS CONTINUE TO VARY WIDELY IN THEIR HANDLING OF THIS
FEATURE. THIS COULD BE THE NEXT PRECIP MAKER FOR THE REGION BUT
CONFIDENCE TOO LOW GIVEN DISPARITY AMONGST THE MODELS TO INTRODUCE
POPS ATTM.

&&

.PRELIMINARY POINT TEMPS/POPS...
FRIONA        29  25  51  26  61 /  90  30   0   0   0
TULIA         28  25  53  25  60 /  90  40   0   0   0
PLAINVIEW     28  26  53  26  61 /  90  40   0   0   0
LEVELLAND     30  25  56  27  64 /  90  40   0   0   0
LUBBOCK       30  27  56  27  63 /  90  40   0   0   0
DENVER CITY   30  27  56  29  65 /  90  40   0   0   0
BROWNFIELD    30  26  55  28  65 /  90  40   0   0   0
CHILDRESS     32  28  54  31  61 /  50  60  10   0   0
SPUR          31  27  55  29  65 /  60  60   0   0   0
ASPERMONT     32  30  55  31  67 /  60  60  10   0   0

&&

.LUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 9 AM THIS MORNING TO 6 AM CST
MONDAY FOR THE FOLLOWING ZONES: TXZ021>044.

&&

29

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LUBBOCK TX
534 AM CST SUN FEB 12 2012

TXZ021>044-131145-
PARMER-CASTRO-SWISHER-BRISCOE-HALL-CHILDRESS-BAILEY-LAMB-HALE-
FLOYD-MOTLEY-COTTLE-COCHRAN-HOCKLEY-LUBBOCK-CROSBY-DICKENS-KING-
YOAKUM-TERRY-LYNN-GARZA-KENT-STONEWALL-
534 AM CST SUN FEB 12 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE EXTREME SOUTHERN TEXAS
PANHANDLE...SOUTH PLAINS AND ROLLING PLAINS.

.DAY ONE...TODAY AND TONIGHT

WINTER WEATHER

WINTRY PRECIPITATION IS EXPECTED TO MOVE ACROSS THE SOUTH PLAINS
AREA TODAY AND TONIGHT. ONE TO TWO INCHES OF SNOW IS POSSIBLE
MAINLY ACROSS THE SOUTH PLAINS...ALTHOUGH MEASURABLE SNOW OR ICE
ACCUMULATION IS POSSIBLE ACROSS ALL OF THE AREA. SEE THE WINTER
WEATHER ADVISORY THAT REMAINS IN EFFECT FOR MORE DETAILS.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.