FXUS64 KFWD 151108 AAA
AFDFWD
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
508 AM CST TUE DEC 15 2009
.AVIATION...
COLD CANADIAN HIGH PRESSURE WILL BUILD INTO NORTH TEXAS TODAY
THEN SLIDE OFF EAST WEDNESDAY. METROPLEX TAFS WILL BE VFR...BUT
KACT WILL HAVE BKN-OVC050 THROUGH THIS MORNING...THEN SCATTER OUT
THIS AFTERNOON. NORTHERLY WINDS WILL HOLD UP 14-19+KTS...THEN
WEAKEN TONIGHT. LOOKING FOR WINDS TO VEER EASTERLY WEDNESDAY
MORNING.
ALL PRECIPITATION SHOULD REMAIN SOUTH THROUGH EAST OF KACT THIS MORNING.
FELL THE -SN REPORT FROM KACT AT 151051Z TO BE FALSE. 75
&&
.PREV DISCUSSION... /ISSUED 410 AM CST TUE DEC 15 2009/
TODAY THROUGH FRIDAY...
ONGOING RAIN SHOWER/ISOLD TSTM ACTIVITY OVER SOUTHEASTERN COUNTIES
OF THE CWA SHOULD DIMINISH AFT 12Z AS THE H850 REFLECTION OF THE
SLOPING COLD FRONT MOVES SOUTHEAST EARLY THIS MORNING. LEDBETTER
WIND PROFILER INDICATES THAT H850 WINDS ARE VEERING AS OF
09Z...AND EXPECT THIS TO CONTINUE THROUGH THE MORNING HRS CAUSING
LOW LVL ISENTROPIC LIFT TO DIMINISH OVER THE CWA. PLACED MENTION
OF ISOLD RAIN SHOWER ACTIVITY ALONG AND SOUTHEAST OF AN ATHENS TO
KILEEN LINE THIS MORNING FOR ANY LINGERING ACTIVITY. OTHERWISE 09Z
WATER VAPOR IMAGERY DEPICTS SHORTWAVE TROUGH MOVING SOUTHEAST INTO
NORTHERN MEXICO THIS MORNING. DOWNSTREAM OF THIS FEATURE MID TO
HIGH LVL CLOUDS CONTINUE TO STREAM OVER NORTH TX. AS THIS TROUGH
CONTINUES SOUTHEAST TODAY...EXPECT SKIES TO CLEAR ACRS THE AREA
FROM NORTHWEST TO SOUTHEAST. DESPITE CLEARING SKIES THINK
PERSISTENT NORTHERLY WINDS AND LOW LVL COLD AIR ADVECTION WILL
KEEP HIGHS FAIRLY COOL TODAY...AND UNDERCUT GUIDANCE BY A COUPLE
OF DEGREES WITH A COOLER THAN EXPECTED START TO THE DAY FOR MOST
LOCATIONS.
GFS/NAM BOTH BRING THE SHORTWAVE TROUGH MOVING INTO NORTHERN
MEXICO THIS MORNING EAST SOUTHEAST DURING THE DAY ON WEDNESDAY
WHILE GRADUALLY WEAKENING AS IT MOVES BACK INTO TX. WEDNESDAY
NIGHT AND THURSDAY MODELS BRING THIS FEATURE BACK NORTHEAST...BUT
WEAKEN IT SO MUCH IT IS LARGELY ABSORPED INTO THE MEAN FLOW BY
THURSDAY AFTERNOON PROVIDING LITTLE IMPACT TO THE FORECAST AREA.
THE ECMWF IS NOTABLY STRONGER AND A BIT FURTHER NORTH WITH THIS
FEATURE AND AS THE ECMWF LIFTS THE TROUGH NORTHEAST...IT BRINGS A
RETURN OF H850 MOISTURE OVER THE CWA. IF THIS WERE TO OCCUR...LOW
LVL ISENTROPIC LIFT AND THE LARGE SCALE FORCING FOR ASCENT
ASSOCIATED WITH THE TROUGH ITSELF WOULD LIKELY BE SUFFICIENT TO
CAUSE SOME LIGHT RAIN TO DEVELOP OVER SOUTHEASTERN PORTIONS OF THE
CWA. THE ECMWF SEEMS TO BE AN OUTLIER AT THIS TIME AND THEREFORE
WENT WITH THE GFS/NAM SOLUTION IN THIS FORECAST PACKAGE AND KEPT
THINGS DRY. ON FRIDAY ALL MODELS BRING A NORTHERN STREAM SHORTWAVE
TROUGH THROUGH THE PLAINS WHICH WILL SEND ANOTHER COLD FRONT SOUTH
THRU NORTH TX DURING THE DAY ON FRIDAY. WITH LITTLE OPPORTUNITY
FOR MOISTURE RETURN...DO NOT FEEL THIS FRONT WILL BRING ANY
PRECIPITATION TO THE CWA.
THIS WEEKEND INTO EARLY NEXT WEEK...CONCERNING THE UPPER TROUGH
DIGGING SOUTH THRU THE PLAINS ON FRIDAY...MODELS CONTINUE TO
DIFFER ON ITS EXACT PLACEMENT. THE GFS IS FURTHER EAST WITH THE
PASSAGE OF THE TROUGH GIVING US MORE OF A GLANCING BLOW OF COOL
AIR HEADED INTO THE WEEKEND WHILE THE ECMWF BRINGS THE TROUGH
RIGHT OVER NORTH TX...SENDING A CP AIRMASS INTO THE AREA. IN
GENERAL GFS IS MUCH WARMER THAN ECMWF DURING THE PERIOD. FOR
NOW...UNTIL SOME SORT OF CONSENSUS OCCURS CONTINUED THE TREND OF
UNDERCUTTING GFS GUIDANCE RATHER THAN FULLY ADOPTING THE ECMWF
NUMBERS. KEPT THE EXTENDED FORECAST DRY AS OPPORTUNITIES FOR
MOISTURE RETURN CONTINUE TO LOOK LIMITED AT THIS TIME.
CAVANAUGH
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 45 30 55 37 59 / 5 0 0 0 0
WACO, TX 48 30 56 37 59 / 10 0 0 10 5
PARIS, TX 47 27 55 31 57 / 5 0 0 0 0
DENTON, TX 44 26 54 32 58 / 5 0 0 0 0
MCKINNEY, TX 46 28 55 34 58 / 5 0 0 0 0
DALLAS, TX 46 32 55 39 59 / 5 0 0 0 0
TERRELL, TX 48 31 57 35 59 / 5 0 0 0 0
CORSICANA, TX 50 31 58 36 59 / 10 0 0 5 5
TEMPLE, TX 49 33 55 37 59 / 20 5 5 10 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
75/
