Blizzard and Winter Storm in Texas, December 23 to 24, 2009

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LUBBOCK TX
946 PM CST WED DEC 23 2009

.UPDATE...
UPPER LOW NEAR ROSWELL NEW MEXICO ROTATING TO THE EAST-SOUTHEAST
SHOULD BE ABOUT ON TRACK WITH LATEST RUC AND WRF/NAM SOLUTIONS.
BOTH NOW SHOW HEAVY SNOW BAND ACROSS MUCH OF AREA OVERNIGHT INTO
EARLY THURSDAY. HAVE EXPANDED THE WINTER STORM WARNING INTO
SOUTHERN ROLLING PLAINS WITH THIS ISSUANCE. ALSO ADDED MORE
BLOWING SNOW LATER TONIGHT AND EARL THURSDAY. ADJUSTED THURSDAY
HIGHS DOWN SLIGHTLY MOST AREAS WITH ANTICIPATED COLD ADVECTION AND
PROBABLE SNOW COVER. RMCQUEEN

&&

.PREV DISCUSSION... /ISSUED 520 PM CST WED DEC 23 2009/

AVIATION...
POTENT WINTER STORM ACROSS NEW MEXICO CONTINUED TO PROVIDE THE
SOUTH PLAINS WITH PRECIPITATION IN LIQUID FORM AT THIS TIME. AS
TEMPERATURES CONTINUED TO FALL THIS EVENING...SNOW WILL BE THE
DOMINATING PRECIPITATION TYPE. AS OF 23Z...KLBB WAS REPORTING IFR
FOG AND CLOUD DECK CONDITIONS WITH MODERATE RAIN. THE BAND OF
PRECIPITATION HAS NOT YET REACHED KCDS...BUT WILL IN THE NEXT
HOUR OR SO. MVFR TO IFR CRITERIA WILL PREVAIL THROUGHOUT MOST OF THE
TAF PERIOD AT BOTH SITES...WITH CHANCES OF RASN AND RAPL
DEVELOPING LATER TONIGHT AT KLBB AND KCDS RESPECTIVELY...BEFORE
COMPLETELY CHANGING OVER TO SN. WINDY CONDITIONS MAY OCCUR
THURSDAY AFTERNOON IN THE WAKE OF THE PROPAGATING WINTER STORM
SYSTEM...POSSIBLY INDUCING BLOWING SN IF IT HAS YET HAD A CHANCE
TO MELT.

PREV DISCUSSION... /ISSUED 405 PM CST WED DEC 23 2009/

SHORT TERM...
STRONG WINTER STORM WITH SIGNIFICANT IMPACTS FOR THE SOUTH PLAINS
DEVELOPING AS WE SPEAK. UPPER LOW CURRENTLY DIGGING ACROSS CENTRAL
NM EXPECTED TO CONTINUE TO DEEPEN AS IT TRACKS ACROSS THE NORTHERN
PERMIAN BASIN THIS EVENING. THIS WILL PUT THE SOUTH PLAINS IN PRIME
LOCATION FOR HEAVY SNOW. EXPECT BAND OF HEAVIEST PRECIPITATION TO
EXTEND FROM JUST WEST OF LUBBOCK NORTHEAST INTO THE NORTHERN ROLLING
PLAINS BY 12Z THU. HAVE THEREFORE UPGRADED TO WINTER STORM WARNING
FOR MUCH OF THE AREA WITH AMOUNTS OF 4-6 INCHES EXPECTED WITH
LOCALLY HIGHER STORM TOTALS.

COLD FRONT HAS SLOWLY BEEN WORKING SOUTH THROUGH THE NORTHERN
COUNTIES TODAY AND WILL SURGE SOUTH THIS EVENING AS SURFACE LOW
MOVES INTO N TX IN ADVANCE OF THE UPPER SYSTEM. LARGE SCALE FORCING
ALREADY UNDERWAY WITH LARGE PRECIPITATION SHIELD EXTENDING FROM THE
PANHANDLE ACROSS THE WESTERN SOUTH PLAINS INTO FAR WEST TEXAS.
TEMPERATURES HAVE QUICKLY COOLED UNDER HEAVIEST PRECIP WITH SNOW
BEING REPORTED ACROSS THE NORTHWEST SOUTH PLAINS AND SOUTHWEST
PANHANDLE AS OF 21Z. PRECIP THIS EVE WILL BE ENHANCED SOME BY MID LEVEL
FRONTOGENETICAL FORCING AND UPPER LEVEL DIVERGENCE ASSOCIATED WITH
140KT SUBTROPICAL JET EJECTING ACROSS THE BIG BEND. CONFIDENCE IN
HEAVIER AMOUNTS INCREASED WITH 18Z NAM DEPICTING SYSTEM TAKING MORE
SOUTHERN TRACK JUST SOUTH OF THE AREA PROVIDING DEEP AND PERSISTENT
LIFT IN FAVORED DENDRITIC GROWTH ZONE FROM AROUND 00Z THROUGH
MIDNIGHT. NO CG STRIKES HAVE BEEN OBSERVED WITH SYSTEM THIS
AFTERNOON...AND CONVECTIVE POTENTIAL ACCORDING TO EPV FIELDS LOOKS
TO BE LIMITED TO AREAS SOUTH AND EAST OF THE MAIN PRECIP SHIELD.
STILL SOME HEAVIER BANDS LIKELY TO DEVELOP AS DEFORMATION ZONE SETS
UP NORTH OF THE UPPER LOW TRACK.

PRECIPITATION WILL BE SLOW TO END THURSDAY MORNING ACROSS THE
ROLLING PLAINS AS TROWAL REGION EXTENDS ALONG THE RED RIVER.
PRECIPITATION ON THE CAPROCK HOWEVER SHOULD TAPER OFF QUICKLY AFTER
12Z THU WITH BULK OF ACCUMULATION SNOW ENDING THERE BY 09Z. LATEST NAM
FALLING IN LINE WITH THE 12Z GFS ON STRONG SURFACE WINDS DEVELOPING
TOWARD DAYBREAK ACROSS THE AREA AS SURFACE LOW DEEPENS NEAR ARKLATEX
REGION AND CANADIAN HIGH PRESSURE BEGINS TO NOSE INTO THE HIGH
PLAINS. WINDS TO ADVISORY LEVEL /GREATER THAN 30 MPH/ WILL BE
POSSIBLE ESPECIALLY OFF THE CAPROCK THURSDAY. WITH THE POTENTIAL FOR
CONTINUED SNOWFALL AND/OR SNOW ON THE GROUND NEAR WHITE-OUT
CONDITIONS WILL BE A POSSIBILITY NORTH OF THE HIGHWAY 70 CORRIDOR
AND ALONG AND EAST OF INTERSTATE 27. HAVE THEREFORE EXTENDED THE
WINTER STORM WARNING THROUGH 18Z THU PRIMARILY FOR WIND/BLOWING SNOW
THREAT. NEXT SHIFTS WILL HAVE TO MONITOR FOR POSSIBLE WIND ADVISORY
EXTENDING PAST WINTER STORM WARNING THURSDAY AFTERNOON OFF THE
CAPROCK.

NEXT POLAR JET DROPS INTO NM LATE THU AND PREVIOUS FORECAST HAD SOME
LIGHT SNOW CHANCES FAR NW LATE IN THE DAY. HAVE MAINTAINED THAT BUT
LIKELIHOOD OF ADDITIONAL ACCUMULATIONS LOOKS VERY LIMITED ATTM IF
PRECIP MATERIALIZES AT ALL.

LONG TERM...
00Z FRIDAY THROUGH DAY 7
WINTER STORM SHOULD BE EXITING THE REGION BY THE START OF THE FCST
PERIOD WITH MERGING OF UPPER LEVEL LOW MOVING SOUTH OUT OF THE
CANADIAN PRAIRIES BEFORE PUSHING TOWARD NEW ENGLAND.  OUT
WEST...STRONG RIDGING BUILDS ACROSS THE PACIFIC COAST WHICH PERSISTS
THROUGH THE WEEKEND. BY LATE MONDAY...NEGATIVELY TILTED TROUGH
SLIDES IN UNDER THE RIDGE YIELDING THE NEXT CHANCE OF PRECIP ACROSS
THE AREA.

RETURN FLOW ATTEMPTS TO BECOME ESTABLISHED ACROSS THE WEST ON FRIDAY
MORNING BEFORE ANOTHER COLD FRONT REINFORCES THE NORTHERLY FLOW...AT
LEAST UNTIL SUNDAY. THERE IS SOME RISK OF SOME LIGHT PRECIP
DEVELOPING ON THE BACK SIDE OF THE LOW...BUT...AT
PRESENT...SOUNDINGS APPEAR TOO DRY.  SOUTHEASTERLY UPSLOPE FLOW
THEN BECOMES ESTABLISHED AREAWIDE WITH SOME RAIN SHOWER ACTIVITY
POSSIBLE LATE MONDAY CHANGING OVER TO SNOW ON TUESDAY. 26

&&

.PRELIMINARY POINT TEMPS/POPS...
FRIONA        21  30  15  35  14 /  80  20  10  10   0
TULIA         23  30  16  36  15 /  90  20  10  10   0
PLAINVIEW     24  29  18  37  16 /  90  30  10  10   0
LEVELLAND     24  30  19  40  18 /  80  20   0  10   0
LUBBOCK       25  32  20  39  19 /  90  30   0  10   0
DENVER CITY   26  38  21  43  19 /  70  20   0   0   0
BROWNFIELD    26  36  21  42  19 /  80  20   0  10   0
CHILDRESS     29  31  19  38  19 /  90  50  10  10   0
SPUR          30  35  21  41  20 /  90  50   0  10   0
ASPERMONT     31  37  21  41  21 /  80  60  10   0   0

&&

.LUB WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL NOON CST THURSDAY FOR THE FOLLOWING
ZONES: TXZ022>044.

WINTER WEATHER ADVISORY UNTIL NOON CST THURSDAY FOR THE
FOLLOWING ZONES: TXZ021.

&&

05/99

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LUBBOCK TX
402 PM CST WED DEC 23 2009

TXZ021>044-242215-
PARMER-CASTRO-SWISHER-BRISCOE-HALL-CHILDRESS-BAILEY-LAMB-HALE-
FLOYD-MOTLEY-COTTLE-COCHRAN-HOCKLEY-LUBBOCK-CROSBY-DICKENS-KING-
YOAKUM-TERRY-LYNN-GARZA-KENT-STONEWALL-
402 PM CST WED DEC 23 2009

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

WINTER WEATHER

WINTER STORM WARNINGS AND ADVISORIES ARE IN EFFECT. SNOWFALL...
NOW ONGOING OVER THE EXTREME SOUTHWESTERN PANHANDLE AND THE
NORTHWESTERN SOUTH PLAINS...WILL GRADUALLY OVERSPREAD THE REMAINDER
OF THE REGION THIS EVENING. A PERIOD OF HEAVY SNOW IS EXPECTED TO
DEVELOP OVER THE CENTRAL AND NORTHERN SOUTH PLAINS BY LATE
EVENING...AND PERSIST NORTHEASTWARD TOWARD THE EXTREME SOUTHEAST
PANHANDLE AND THE NORTHERN ROLLING PLAINS OVERNIGHT. WIDESPREAD
ONE INCH ACCUMULATIONS ARE EXPECTED...WITH A BROAD AREA OF 3 TO 6
INCH ACCUMULATIONS EXPECTED OVER THE CENTRAL AND NORTHERN SOUTH
PLAINS...AND THE SOUTHEASTERN PANHANDLE AND NORTHERN ROLLING
PLAINS BY THURSDAY MORNING. LOCALIZED HIGHER SNOW TOTALS ARE
POSSIBLE. PLEASE REFER TO THE CURRENT WARNINGS AND ADVISORIES
FOR COUNTY SPECIFIC FORECASTS AND IMPACTS.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

TONIGHT/S WINTER STORM WILL LINGER INTO THURSDAY MORNING...
ESPECIALLY OVER THE EXTREME SOUTHEASTERN PANHANDLE AND THE
NORTHERN ROLLING PLAINS. NORTHERLY WINDS SUSTAINED AROUND 30 MPH
WILL RESULT IN AREAS OF BLOWING SNOW THERE BETWEEN SUNRISE AND
MIDDAY.

.SPOTTER INFORMATION STATEMENT...

LOCAL AUTHORITIES AND EMERGENCY PERSONNEL ARE ENCOURAGED TO
RELAY REPORTS OF SNOWFALL AND PUBLIC IMPACTS TO THE NATIONAL
WEATHER SERVICE IN LUBBOCK.