000 FXUS64 KFWD 241658 AAA AFDFWD AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE FORT WORTH TX 1058 AM CST TUE NOV 24 2009 .AVIATION... NO AVIATION WEATHER CONCERNS THROUGH WEDNESDAY WITH A CLEAR SKY AND A NORTHWEST WIND. WIND SPEEDS TODAY WILL RANGE FROM 12 TO 15 KNOTS WITH SOME GUSTS IN EXCESS OF 20 KNOTS. WIND SPEEDS WILL FALL BELOW 10 KNOTS AFTER SUNSET AND REMAIN THAT WAY THROUGH WEDNESDAY. 79 && .UPDATE... ONLY A FEW ADJUSTMENTS NEEDED TO THE ONGOING FORECAST. HAVE INCREASED WIND SPEEDS THIS MORNING AND AFTERNOON...LOWERED SKY COVER...AND PULLED SHOWERS FROM THE SOUTHERN ZONES. && .PREV DISCUSSION... /ISSUED 523 AM CST TUE NOV 24 2009/ 443 AM TODAY THROUGH FRIDAY...THE STRONG UPPER LEVEL SHORTWAVE TROUGH THAT WAS FORECAST TO MOVE THROUGH KS AND OK OVERNIGHT MOVED THROUGH AS EXPECTED AND IS GETTING READY TO EXIT THE SOUTHERN PLAINS OFF TO THE NORTHEAST DURING THE DAY TODAY. THE COLD FRONT THAT PUSHED THROUGH DURING THE OVERNIGHT HRS AS A RESULT OF THIS UPPER LVL SYSTEM MOVING THROUGH THE PLAINS TO OUR NORTH HAS NEARLY CLEARED ALL COUNTIES OF THE CWA AT FORECAST TIME. AT 4 AM CST THE COLD FRONT WAS LOCATED NEAR A PARIS TO ATHENS TO TEMPLE LINE...CONTINUING TO MOVE SOUTHEAST AT 20 TO 25 MPH. BY SUNRISE THE COLD FRONT IS EXPECTED TO HAVE PUSHED JUST SOUTH AND EAST OF ALL COUNTIES IN NORTH TX. THERE IS A LINE OF ISOLATED TO SCATTERED LIGHT RAIN SHOWERS JUST BEHIND THE COLD FRONT...AND HAVE LEFT A SMALL AREA OF 20 PERCENT CHANCE OF RAIN ACRS OUR SOUTHEASTERN COUNTIES TO COVER THE COUPLE OF HUNDREDTHS OF AN INCH THAT MAY FALL DURING THE EARLY MORNING HRS. OTHERWISE LOW LVL DRY AIR IS ALREADY INFILTRATING NORTH TX BEHIND THIS FRONT...WITH DEW POINT VALUES FALLING 15 TO 20 DEGREES RIGHT BEHIND THE COLD FRONT. DRIER AIR IS EXPECTED TO PROMOTE SUNNY SKIES TODAY WHILE PERSISTENT NORTHWESTERLY WINDS ARE EXPECTED TO KEEP HIGHS IN THE UPPER 50S TO LOWER 60S DESPITE PLENTIFUL SUNSHINE. THE DRY PATTERN LOOKS TO HOLD FOR THE REMAINDER OF THIS FORECAST PERIOD. ANOTHER STRONG UPPER LVL SHORTWAVE TROUGH IS FORECAST TO DIVE SOUTH THROUGH THE PLAINS ON WEDNESDAY...SENDING ANOTHER WEAK COLD FRONT/REINFORCING SHOT OF COOL...DRY AIR SOUTH THROUGH NORTH TX WEDNESDAY NIGHT. THIS SECONDARY FRONT WILL KEEP LOW LVL FLOW OUT OF NORTH NORTH FOR MUCH OF THE DAY ON THURSDAY...ONCE AGAIN KEEPING HIGH TEMPERATURES IN CHECK DESPITE PLENTIFUL SUNSHINE. THURSDAY NIGHT AND INTO FRIDAY UPPER RIDGING RETURNS TO THE PLAINS AS ANOTHER STRONG UPPER TROUGH MOVES ONSHORE THE WESTERN CONUS. FRIDAY SHOULD THEREFORE SEE A RETURN TO LOW LVL SOUTHERLY FLOW WITH WARMER TEMPERATURES HEADED INTO THE WEEKEND. SATURDAY THROUGH TUESDAY...GFS/ECMWF ARE CONSISTENT IN BRINGING A DEEP TROUGH THRU THE WESTERN CONUS WITH A STRONG PIECE OF ENERGY EJECTING OUT NORTHEAST THRU TX DURING THIS PERIOD. FOR SATURDAY AND INTO SUNDAY MORNING BOTH MODELS HAVE SOUTHWEST FLOW ALOFT OF THE SOUTHERN PLAINS WHICH SHOULD PROMOTE GOOD CYCLOGENESIS NEAR THE TX/OK PANHANDLES AND START BRINGING GULF MOISTURE BACK INTO THE REGION. AFTER SUNDAY MORNING THE MODELS BEGIN TO DIVERGE QUITE A BIT AS THE GFS KICKS THE STRONGEST PIECE OF ENERGY THRU TX SUNDAY NIGHT WHILE THE ECMWF HOLDS THIS ENERGY BACK UNTIL CLOSER TO MONDAY NIGHT. WHENEVER THIS ENERGY KICKS OUT...THIS WOULD SEEM TO COINCIDE WITH THE BEST CHANCE FOR PRECIPITATION WITH THE STRONG ASSOCIATED LARGE SCALE FORCING FOR ASCENT AND THE PASSAGE OF A STRONG COLD FRONT. THE SLOWER TIMING OF THE ECMWF WOULD ALLOW DEEPER GULF MOISTURE TO ENTER THE REGION LIKELY INCREASING THE OVERALL COVERAGE AND INTENSITY OF PRECIPITATION WHEN THE FRONT ROLLS THROUGH. A SLOWER SOLUTION WOULD ALSO INCREASE THE CHANCES OF ISOLATED TO SCATTERED TSTM ACTIVITY OUT AHEAD OF THE FRONT. FOR NOW THE FORECAST REPRESENTS A BLEND OF THESE TWO SOLUTIONS WITH POPS IN THE FORECAST FROM SATURDAY NIGHT THROUGH MONDAY. IF THE ECMWF DISPLAYS MORE CONTINUITY POPS WILL LIKELY HAVE TO BE EXTENDED IN TIME...WHEREAS THE GFS WOULD INDICATE A QUICKER END TO PRECIP CHANCES AS DRY AIR MOVES IN BEHIND THE FRONT BY MONDAY AFTERNOON. WITH TOO MUCH UNCERTAINTY IN THIS PERIOD DID NOT INCREASE POPS OUT OF THE 30 PERCENT RANGE...HOWEVER ONCE CONFIDENCE INCREASES IN TIMING OF THIS UPPER LVL SYSTEM HIGHER POPS WILL LIKELY BE NEEDED. CAVANAUGH && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 60 38 63 39 64 / 0 0 0 0 0 WACO, TX 62 39 64 37 66 / 0 0 0 0 0 PARIS, TX 59 39 61 37 60 / 5 0 0 0 0 DENTON, TX 59 37 62 33 63 / 0 0 0 0 0 MCKINNEY, TX 59 37 62 37 63 / 0 0 0 0 0 DALLAS, TX 60 39 63 40 64 / 0 0 0 0 0 TERRELL, TX 61 39 63 39 63 / 0 0 0 0 0 CORSICANA, TX 62 38 63 39 65 / 0 0 0 0 0 TEMPLE, TX 62 39 64 36 66 / 0 0 0 0 0 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 79/21