641
FXUS64 KFWD 211048
AFDFWD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
448 AM CST SAT NOV 21 2009
DISCUSSION
TODAY...AREAS OF LIGHT DRIZZLE ARE EXPECTED TO CONTINUE TO DEVELOP
ACROSS MUCH OF NORTH TEXAS THROUGH THE MORNING HOURS. THIS LIGHT
PRECIPITATION WILL REDUCE VISIBILITIES SO PLACED MENTION OF FOG IN
THE MORNING FORECAST AS WELL. A MORE ORGANIZED AREA OF STRATIFORM
RAINFALL EXISTS IN THE WACO AREA EARLY THIS MORNING...AND THIS
SEEMS TO CORRELATE WELL WITH LARGE SCALE FORCING FOR ASCENT
ASSOCIATED WITH THE UPPER LEVEL SHORTWAVE TROUGH LOCATED OVER
SOUTHEASTERN TX. THIS UPPER LVL FEATURE IS EXPECTED TO MOVE OFF TO
THE NORTHEAST TODAY BRINGING SUBSIDENCE THROUGH NORTH TX BRINGING
LIGHT PRECIPITATION TO AN END BY THIS AFTERNOON. MODELS SHOW UPPER
AND MID LVL CLOUDS DISSIPATING QUICKLY AS SUBSIDENCE BUILDS OVER
NORTH TX...HOWEVER LOW CLOUDS ARE EXPECTED TO BE A BIT MORE
RESILIENT AND WILL BEGIN TO DISSIPATE DURING MID AFTERNOON HRS.
TODAY'S HIGHS ARE TRICKY AS BREAKS IN THE CLOUD COVER ARE LIKELY TO
CAUSE TEMPS TO RISE ABOVE THE LOWER 60S THAT ARE IN THE
FORECAST...HOWEVER AT FORECAST TIME LOW LEVEL STRATUS CONTINUED TO
EXPAND NORTH AND WEST OF THE CWA...SO LOW CLOUDS LOOK LIKELY TO
HANG IN FOR MUCH OF THE DAY.
TONIGHT THROUGH MONDAY...SKIES LOOK TO CLEAR OUT TONIGHT IF NOT
DURING THE LATE AFTERNOON HRS...AND A DRY FORECAST LOOKS IN STORE
FOR THIS PERIOD AS WEAK UPPER LVL RIDGING BUILDS OVER THE SOUTHERN
PLAINS. THE NEXT STRONG UPPER LEVEL DISTURBANCE IS EXPECTED TO
MOVE INTO THE NORTHWESTERN CONUS DURING THE DAY ON
SUNDAY...BRINGING CYCLOGENESIS OVER THE CENTRAL AND NORTHERN
PLAINS AND BRINGING A RETURN TO LOW LEVEL SOUTHERLY FLOW OVER
NORTH TX. SOUTHERLY FLOW LOOKS TO CONTINUE THROUGH THE DAY ON
MONDAY...AND 24-36 HRS OF SOUTHERLY WINDS WILL SEND SOME GULF
MOISTURE BACK NORTH THROUGH THE CWA AND INTO MO VALLEY BY MONDAY
EVENING.
MONDAY NIGHT AND TUESDAY...THE STRONG SHORTWAVE TROUGH LOOKS TO
MOVE INTO THE PLAINS AND THEN INTO THE GREAT LAKES REGION BY
TUESDAY EVENING. THIS WILL SEND A COLD FRONT SOUTH THRU NORTH TX
BEGINNING MONDAY NIGHT AND MOVING SOUTH THRU THE ENTIRE FORECAST
AREA BY TUESDAY AFTERNOON. WHILE GULF MOISTURE IS EXPECTED TO
RETURN TO THE SOUTHERN PLAINS...DID NOT PLACE TSTMS IN THE
FORECAST AS THE GULF MOISTURE RETURN IS SOMEWHAT SHALLOW IN NATURE
AND THE BULK OF THE LARGE SCALE FORCING FOR ASCENT REMAINS WELL
NORTH OF THE RED RIVER PER 00Z MODEL GUIDANCE. REGARDLESS...THINK
LOW LVL MOISTURE IS SUFFICIENT TO ALLOW RAIN SHOWER ACTIVITY TO
DEVELOP ALONG THE COLD FRONT AS IT MOVES THROUGH THE AREA. FOR NOW
DO NOT EXPECT HEAVY RAINFALL OR ANY SVR WX ASSOCIATED WITH THE
FRONT. DRIER AIR BEHIND THE FRONT SHOULD BRING A RETURN TO MOSTLY
CLEAR SKIES BY TUESDAY EVENING.
EXTENDED FORECAST...ANOTHER STRONG SHORTWAVE TROUGH IS EXPECTED TO
DIG INTO THE BACK OF THE EXITING TROUGH OVER THE GREAT LAKES
REGION WEDNESDAY AND WEDNESDAY NIGHT. THIS WOULD NORMALLY BRING A
BACK DOOR TYPE COLD FRONT THRU THE SOUTHERN PLAINS...BUT CHANCES
ARE THE UPPER TROUGH WILL ONLY SEND A REINFORCING SHOT OF
COOL...DRY AIR THROUGH THE REGION. WITH MERIDIONAL FLOW REMAINING
OVER THE PLAINS IN BETWEEN THESE TWO SYSTEMS A RETURN TO SOUTHERLY
FLOW AND ASSOCIATED MOISTURE RETURN SEEMS UNLIKELY AT THIS
TIME...SO DID NOT BRING MUCH IN THE WAY OF CLOUDS OR PRECIP INTO
THE CWA WITH THIS SECOND FEATURE. BEYOND THURSDAY THE MODELS BEGIN
TO DIVERGE ON SOLUTIONS IN THE LARGE SCALE FLOW PATTERN...WITH TOO
MUCH UNCERTAINTY IN ANY ONE SOLUTION HAVE MAINTAINED A DRY
FORECAST FOR NOW AS ANY RETURN OF GOOD QUALITY GULF MOISTURE SEEMS
UNLIKELY WITH TWO SHOTS OF COOL...DRY AIR COMING IN EARLIER IN THE
FORECAST PERIOD.
CAVANAUGH
PRELIMINARY POINT TEMPS/POPS
DALLAS-FT. WORTH, TX 62 46 67 47 70 / 20 0 0 0 0
WACO, TX 62 46 68 49 70 / 40 0 0 0 0
PARIS, TX 61 43 66 45 67 / 20 0 10 0 0
DENTON, TX 62 44 67 45 69 / 20 0 10 0 0
MCKINNEY, TX 63 43 66 45 68 / 20 0 10 0 0
DALLAS, TX 62 47 67 50 69 / 20 0 0 0 0
TERRELL, TX 63 43 67 45 69 / 20 0 0 0 0
CORSICANA, TX 63 44 68 48 70 / 40 0 0 0 0
TEMPLE, TX 62 47 69 47 70 / 30 0 0 0 0
FWD WATCHES/WARNINGS/ADVISORIES
NONE.
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