FXUS64 KLUB 281740
AFDLUB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LUBBOCK TX
1140 AM CST SAT NOV 28 2009

.AVIATION...
HIGH LEVEL CLOUDS WILL CONTINUE TO INCREASE THIS AFTERNOON WITH
THE APPROACH OF A STRONG UPPER LEVEL SYSTEM FROM THE WEST. A COLD
FRONT WILL MOVE THROUGH THE AREA BEGINNING BEFORE MIDNIGHT NEAR
KCDS AND AFTER MIDNIGHT AT KLBB. WINDS WILL REMAIN BREEZY OUT OF
THE NORTH THROUGHOUT THE MORNING HOURS ON SUNDAY BEHIND THIS
FRONT. RAIN CHANCES WILL ALSO INCREASE BEHIND THIS FRONTAL PASSAGE
WITH POSSIBLE MVFR CONDITIONS AS WELL.

&&

PREV DISCUSSION... /ISSUED 425 AM CST SAT NOV 28 2009/

SHORT TERM...
MAIN FOCUS FOR THE SHORT TERM FORECAST WILL BE THE POTENTIAL FOR
INCREASING PRECIPITATION CHANCES TOWARDS THE END OF THE WEEKEND.

UPPER LEVEL SHORTWAVE CURRENTLY ACROSS CENTRAL TEXAS WILL SLIDE 
NORTHEAST OF THE CWA BY THIS AFTERNOON...AS A POTENT CUT OFF LOW 
DIVES SE ACROSS SOUTHERN CALIFORNIA. MODEL FORECASTS HINT AT MID TO 
UPPER LEVEL THICKNESS VALUES INCREASING THROUGHOUT THE DAY...AS 
SOUTHWESTERLY FLOW ALOFT PREVAILS. THUS...THIS WILL INDUCE TEMPS TO 
WARM 10 TO 15 DEGREES ABOVE SEASONAL NORMS. WITH SUCH WARM TEMPS AND 
SFC WINDS VEERING TO THE WEST SOUTHWEST...DRYING/LOW RH VALUES COULD 
RAISE CONCERNS FOR FIRE WEATHER POTENTIAL. HOWEVER...WIND SPEEDS 
SHOULD STAY BELOW CRITICAL LEVELS. REFER TO THE FIRE WEATHER 
PLANNING FORECAST FOR FURTHER DETAILS. THIS EVENING...MODEL 
SOUNDINGS DISPLAYED INCREASING SYNOPTIC LIFT AND CLOUD COVER AHEAD 
OF THE AFOREMENTIONED UA LOW AND A NORTHERLY COLD FRONTAL BOUNDARY. 
OMEGA AND PWAT VALUES INCREASES FURTHER BY EARLY SUNDAY 
MORNING...TIMING IT WELL WITH THE BEST FRONTOGENETICAL LIFT AND 
INCOMING WESTERLY UPPER LEVEL DISTURBANCE. THUS...WILL MAINTAIN 
MENTIONABLE POPS TONIGHT THROUGH EARLY SUNDAY MORNING WITH 
INCREASING COVERAGE FROM WEST TO EAST. SOUNDING PROFILES EXHIBITED 
SFC TEMPS REMAINING ABOVE FREEZING LEVELS...WITH NWRN ZONES SHOWING 
A SLIGHT HINT OF A SNOW PROFILE. WILL NOT MENTION SNOW ATTM AS THE 
MID-LEVEL WARM NOSE PRESENTED IN THE PROFILE MAY BE ENOUGH TO KEEP 
THE PRECIP TYPE IN LIQUID FORM.

LONG TERM...
UPPER LOW WILL CONTINUE TO HAVE IMPACTS ON WEST TEXAS WEATHER
THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK...MAKING FOR A
PROBLEMATIC FORECAST. COLD FRONT SHOULD BE THROUGH FORECAST AREA
BY 12Z SUNDAY BRINGING AN END TO THE RECENT LONG STRETCH OF VERY
PLEASANT WEATHER. LATEST GFS/EURO RUNS CONTINUE TO INDICATE
SUFFICIENT LIFT OVER FRONTAL BOUNDARY FOR WIDESPREAD LIGHT
PRECIPITATION DURING THE DAY SUNDAY. NAM MUCH DRIER...BUT STILL
SUGGESTS ENOUGH LIFT AND MOISTURE FOR SOME PRECIPITATION. ONGOING
COLD AIR ADVECTION DURING THE DAY SUNDAY MAY BE ENOUGH TO RESULT
IN A MIX OF RAIN AND SNOW OR CHANGEOVER TO SNOW OVER THE EXTREME
SOUTHERN PANHANDLE BY LATE MORNING. SHOULD THIS OCCUR...THINK ANY
ACCUMULATIONS WOULD BE VERY LIGHT. IN ANY EVENT HIGH TEMPERATURES
ON SUNDAY WILL BE A SOLID 30 DEGREES LOWER THAN TODAY ACROSS MOST
SECTIONS.

NEXT AND PERHAPS BIGGER ISSUE IS THE EXACT TRACK OF THE UPPER LOW AS 
IT DIGS INTO NORTHERN MEXICO SUNDAY NIGHT AND EJECTS ACROSS WEST 
TEXAS ON TUESDAY. THIS IS A CLASSIC HEAVY SNOW SYSTEM/PATTERN FOR 
WEST TEXAS WITH THE HEAVY SNOW OBVIOUSLY DEPENDING HEAVILY ON THE 
EVENTUAL PATH OF THE LOW. GFS ADVECTS UPPER LOW ACROSS THE BIG BEND 
AND THEN NORTHEAST INTO CENTRAL TEXAS. ECMWF TAKES THE LOW ON A MORE 
NORTHERN TRACK ACROSS THE NORTHERN PERMIAN BASIN. THEREFORE...HAVE 
INCREASED POPS FOR MONDAY NIGHT AND TUESDAY ACROSS MOST OF THE 
REGION AND WE WILL HAVE TO KEEP A CLOSE EYE ON LATER MODEL RUNS. 
SURFACE TEMPERATURES LOOK A LITTLE WARM AND THINK PROFILES WILL BE 
COLD ENOUGH FOR SNOW OVER MOST OF THE REGION MONDAY NIGHT AND 
TUESDAY. RIDING ON THIS IDEA...WENT WELL BELOW GUIDANCE HIGH 
TEMPERATURES FOR TUESDAY WHICH WILL CERTAINLY BE THE CASE SHOULD 
SNOW DEVELOP. LARGE MODEL DISCREPANCIES CONTINUE THROUGH THE 
REMAINDER OF THE WEEK WHICH WILL MAINLY ONLY IMPACT TEMPERATURES AS 
MAINLY ZONAL MID LEVEL FLOW WILL KEEP THE REGION DRY AFTER TUESDAY. 
JW

&&

.PRELIMINARY POINT TEMPS/POPS...
FRIONA        69  34  38  25  44 /   0  30  40  10  10 
TULIA         72  35  42  27  44 /   0  30  40  10  10 
PLAINVIEW     73  37  43  28  45 /   0  30  40  10  10 
LEVELLAND     73  41  43  29  45 /   0  30  40  20  10 
LUBBOCK       75  39  45  30  45 /   0  30  40  10  10 
DENVER CITY   73  42  43  31  44 /   0  30  40  20  10 
BROWNFIELD    75  42  43  32  46 /   0  30  40  20  10 
CHILDRESS     75  41  47  32  48 /   0  10  40  10  10 
SPUR          74  41  46  34  48 /   0  20  40  20  10 
ASPERMONT     75  45  49  35  48 /   0  10  40  20  10 

&&

.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

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