FXUS64 KMAF 151029
AFDMAF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX
429 AM CST TUE DEC 15 2009

.DISCUSSION...

SEE AVIATION DISCUSSION BELOW.

&&

.AVIATION...

NO MAJOR AVIATION CONCERNS NEXT 24 HRS...AS ALL TERMINALS VFR.  
NORTHERLY SFC WINDS WILL VEER TO THE EAST...AND HIGH CLOUDS WILL 
MOVE THRU THE REGION W/AN UPPER TROUGH.

&&

.PREV DISCUSSION... /ISSUED 306 AM CST TUE DEC 15 2009/ 

DISCUSSION...
WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL TROUGH CURRENTLY OVER NEW 
MEXICO. THIS FEATURE WILL MAKE ITS WAY INTO THE AREA BY THIS 
AFTERNOON. THERE IS GOOD MODEL AGREEMENT BETWEEN THE ECMWF...NAM AND 
GFS AS TO THE SPEED AND MOVEMENT OF THIS TROUGH OVER THE NEXT COUPLE 
OF DAYS. IT WILL REMAIN OVER THE AREA UNTIL THURSDAY MORNING AND 
THEN MOVE OUT OF TEXAS BY THURSDAY EVENING. THERE IS SOME AGREEMENT 
BETWEEN THE ECMWF...NAM AND GFS AS TO WHETHER THERE IS ENOUGH LIFT 
FOR PRECIPITATION TO BE POSSIBLE. THE ECMWF IS SHOWING THE MOST 
WIDESPREAD LIFT OVER THE CWA...BUT ALL THREE MODELS SHOW A SMALL 
AREA ALONG THE RIO GRANDE IN THE BIG BEND AND TERRELL COUNTY AREA. 
DUE TO THIS AGREEMENT A CHANCE OF SHOWERS WAS LEFT IN THE GRIDS FOR 
TUESDAY MORNING. THE WIND AT 700MB AND THE GRADIENT AT THAT LEVEL 
ARE VERY WEAK...SO NO SIGNIFICANT WIND IS EXPECTED WITH THIS TROUGH. 

AT THE SURFACE AN ARCTIC COLD FRONT HAS RECENTLY MADE ITS WAY 
THROUGH THE AREA...HOWEVER THE COLDEST AIR RESIDES TO THE NORTHEAST 
OF THE AREA OVER OKLAHOMA. THE GFS AND NAM KEEP THE HIGH PRESSURE 
AND COLDEST AIR AT THE SURFACE TO THE WEST OF THE AREA THROUGHOUT 
TUESDAY. BOTH MODELS TRY TO SHOW THE LEE TROUGH BUILDING BACK IN BY 
WEDNESDAY MORNING...WHICH WOULD CAUSE THE WIND TO COME FROM A 
SOUTHERLY DIRECTION...HOWEVER THIS WILL BE DIFFICULT WITH TROUGHING 
IN THE UPPER LEVELS THAT WE EXPECTING. FORECASTED TEMPERATURES FOR 
WEDNESDAY...ESPECIALLY IN THE NORTHEASTERN PORTION OF THE CWA...ARE 
LOWER THAN GUIDANCE DUE TO THIS CONTRADICTION IN THE MODEL DATA.

BY THURSDAY THE RIDGE WILL HAVE MOVED OFF TO THE EAST. TEMPERATURES 
WILL WARM BACK UP THAT DAY. THERE IS GOOD AGREEMENT WITH THE 
NAM...GFS AND ECMWF SHOWING A COLD FRONT WILL MAKE ITS WAY TO THE 
AREA FRIDAY. TEMPERATURES WILL BEGIN TO COOL BACK DOWN FRIDAY AND 
REMAIN COOL FOR THE WEEKEND.

&&

.MAF WATCHES/WARNINGS/ADVISORIES...
NM...NONE.
TX...NONE.

&&

$$

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