FXUS64 KOUN 011129
AFDOUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
529 AM CST TUE DEC 1 2009

.AVIATION...
MID LEVEL CEILINGS ARE SPREADING INTO THE SOUTHWESTERN TAF SITES
/KSPS KLAW KHBR KCSM/ ALTHOUGH THE INITIAL ROUND OF RAIN CURRENTLY
OCCURRING IN WEST TEXAS WILL MAINLY STAY WEST OF THESE AIRPORTS.
RAIN CHANCES WILL INCREASE ACROSS THE SOUTHWESTERN SITES TODAY
AND SPREADING INTO CENTRAL OKLAHOMA SITES /KOUN KOKC/ THIS
EVENING AHEAD OF THE UPPER LEVEL STORM SYSTEM THAT WILL TRACK
ACROSS TEXAS TODAY AND TONIGHT. INITIALLY CIGS GENERALLY WILL BE
VFR ALTHOUGH LIKELIHOOD OF MVFR CIGS WILL INCREASE OVERNIGHT IN
THE SOUTHWEST... WITH SOME CHANCE OF IFR CIGS WITH SOME OF THE
RAIN AREAS LATE TONIGHT.

&&

.PREV DISCUSSION... /ISSUED 405 AM CST TUE DEC 1 2009/ 

DISCUSSION...
PRECIP IS EXPANDING ACROSS WEST/SOUTHWEST TEXAS THIS MORNING AHEAD
OF UPPER LOW MOVING INTO CHIHUAHUA... AND MAIN ISSUE WITH THIS
FORECAST IS THE PRECIPITATION ASSOCIATED WITH THIS STORM AS IT
MOVES ACROSS TEXAS. MODELS HAVE BEEN TRENDING TOWARD KEEPING THE
NORTH END OF THE PRECIP SHIELD FARTHER SOUTH... SO ALTHOUGH
PRECIPITATION IS ALMOST CERTAIN ACROSS NORTH TEXAS AND SOUTHERN
OKLAHOMA IT IS UNCLEAR WHERE THE NORTHERN END OF THIS PRECIP WILL
BE. BUT THE 00Z MODELS DID NOT HAVE THE PRECIPITATION SIGNAL AS
FAR NORTH AS IS CURRENTLY OCCURRING BETWEEN MIDLAND AND LUBBOCK
THIS MORNING. HAVE DECREASED POPS SOMEWHAT ACROSS THE CENTRAL AND
NORTH TODAY THROUGH TOMORROW BUT HAVE KEPT POPS AT THE HIGH SIDE
OR ABOVE CURRENT GUIDANCE RANGE. NEXT QUESTION IS PRECIP TYPE AS
MODELS ARE KEEPING LOW LEVEL TEMPERATURES WARMER THAN PREVIOUSLY
INDICATED. BUFR SOUNDINGS SHOW THAT MANY AREAS WILL HAVE A LARGE
ENOUGH AREA OF NEAR-SURFACE TEMPERATURES ABOVE 0C THAT THE
MIX/CHANGE TO SNOW IS MORE IN QUESTION. COOLER LOW-LEVEL
TEMPERATURES FROM THE NORTH WILL BE LATE TO ARRIVE ALTHOUGH THE
SOUTHWESTERN STORM SYSTEM WILL BRING A COOLER COLUMN WITH IT. WILL
MAINTAIN THE CHANCE OF RAIN/SNOW MIX IN THE PACKAGE BUT WILL USE
LOWER SNOW PROBABILITY WORDING... ESPECIALLY IN CENTRAL OKLAHOMA
WHERE LOW-LEVEL TEMPERATURES ARE EXPECTED TO BE WARMER BETWEEN THE
COLDER TEMPERATURES ADVECTING INTO THE NORTH AND THE COOLER COLUMN
CLOSER TO THE STORM SYSTEM TO THE SOUTH.

LOOKING FARTHER AHEAD... THE NORTHERN STREAM TROF EXTENDING
SOUTHWEST FROM THE GREAT LAKES BEGINS TO AFFECT THE PLAINS MORE
AFTER THIS SOUTHWESTERN SYSTEM MOVES NORTHEAST... AND MODELS ARE
DEVELOPING SOME QPF ACROSS THE SOUTHWEST/SOUTH ON THURSDAY NIGHT
AND FRIDAY AS THIS TROF AXIS PIVOTS THROUGH THE AREA. HAVE ADDED
SLIGHT CHANCE POPS BUT WILL NOT BE AS AGGRESSIVE AS SOME OF THE
MEX POPS NUMBERS YET. BELOW AVERAGE TEMPERATURES ARE EXPECTED TO
CONTINUE THROUGH THE FORECAST PERIOD AND ANOTHER COLD FRONT MOVES
INTO THE AREA ON SUNDAY.  .26.

&&

.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK  51  35  44  26 /  30  50  30   0 
HOBART OK         50  33  46  27 /  40  50  20   0 
WICHITA FALLS TX  48  33  47  30 /  70  80  30   0 
GAGE OK           52  27  43  20 /  20  20  10  10 
PONCA CITY OK     56  35  44  23 /  10  30  10   0 
DURANT OK         52  38  47  32 /  40  80  60  10 

&&

.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&

$$

01/01/01