FXUS64 KFWD 112145
AFDFWD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
345 PM CST FRI DEC 11 2009
.DISCUSSION...
UPPER LEVEL SHORTWAVE TROUGH WITHIN THE SOUTHERN BRANCH OF THE
WESTERLIES WILL MOVE ACROSS THE REGION LATE TONIGHT AND EARLY
SATURDAY. ISENTROPIC UPGLIDE WILL INTENSIFY IN RESPONSE TO THIS
FEATURE...WITH 290-295K SURFACES DISPLAYING FAVORABLE MOISTURE/
INSTABILITY PARAMETERS FOR ELEVATED CONVECTION TO DEVELOP
TONIGHT...ESPECIALLY OVER THE SE HALF OF THE CWA. ENOUGH ELEVATED
INSTABILITY WILL BE PRESENT FOR ISOLATED THUNDERSTORMS OVER THE
SOUTHEAST ZONES. A SHARP WEST-EAST GRADIENT IN THE POPS WILL EXIST
WITH LITTLE CHANCE OF MEASURABLE RAIN IN THE WEST. HOWEVER...
ISENTROPIC LIFT OCCURRING IN THE MORE STABLE 285K LAYER WILL CAUSE
DRIZZLE/LIGHT FOG TO DEVELOP LATE TONIGHT OVER THE ENTIRE CWA. THE
CHANCE OF RAIN OR DRIZZLE WILL CONTINUE INTO THE MORNING HOURS
TOMORROW...BUT SHOULD SHUT DOWN AS THE SHORTWAVE AXIS PASSES
THROUGH BY AFTERNOON. TEMPERATURES TONIGHT WILL NOT FALL TOO FAR
FROM CURRENT READINGS DUE TO EXTENSIVE CLOUD COVER. CLOUDS WILL
LINGER THROUGH TOMORROW...WHICH WILL ALSO LIMIT ANY WARM UP...BUT
SOME PARTIAL CLEARING MAY OCCUR OUT WEST.
DRYING ALOFT VIA SUBSIDENCE AND WESTERLY FLOW BEHIND THE DEPARTING
SHORTWAVE WILL OCCUR FROM TOP-DOWN LATE SATURDAY. LOW LEVELS WILL
REMAIN SATURATED AND DEWPOINTS BY THIS TIME WILL BE NEAR OR ABOVE
THE RECENTLY CHILLED GROUND TEMPS...WHICH POINTS TOWARD A ROUND
OF FOG SAT NIGHT. MODELS ARE TRYING TO SCOUR OUT THE LOW LEVEL
MOISTURE WITH WESTERLY FLOW JUST ABOVE THE SURFACE...SO FOG MAY
CLEAR FROM WEST-EAST BY SUNRISE SUNDAY. VERY WARM 850MB TEMPS AND
GENERALLY SUNNY SKIES SUNDAY SHOULD ALLOW TEMPS TO WARM UP SUNDAY
INTO THE 70S. WARM TEMPS WILL CONTINUE INTO MONDAY AHEAD OF THE
NEXT COLD FRONT EXPECTED IN BY MONDAY NIGHT. THERE WILL BE A LOW
CHANCE OF RAIN IN THE SOUTHEAST ZONES WITH THIS FRONT WHERE THERE
WILL BE ENOUGH MOISTURE RETURN.
THE ONLY CONCERN IN THE EXTENDED ARE TEMPERATURES BEHIND THE FRONT
MONDAY NIGHT. POLAR VORTEX NOW OVER THE NW TERRITORIES OF CANADA
WILL ELONGATE AND SHEAR APART THIS WEEKEND...BUT SEND A PIECE OF
ARCTIC AIR INTO THE PLAINS BY MONDAY. LARGELY ZONAL UPPER LEVEL
PATTERN WILL DEFLECT THE COLDEST AIR EASTWARD...AND ALSO RESULT IN
DOWNSLOPE FLOW OFF THE ROCKIES AND SUBSEQUENT MODERATION/WARMING
OF THE WESTERN EDGE OF THIS AIRMASS. SO WHILE WE CAN EXPECT
ANOTHER COOL DOWN NEXT WEEK...TEMPS WILL NOT BE AS COLD AS THEY
WERE THIS PAST WEEK. STILL...GFS LOOKS MUCH TOO WARM AND THE 12Z
MEX MOS IS JUST PLAIN OUT TO LUNCH. HAVE CONTINUED A FORECAST OF
TEMPS A LITTLE BELOW NORMAL FOR NEXT WEEK. VERY DRY AIRMASS SHOULD
BRING ABOUT MAINLY CLEAR SKIES AND SEASONABLY COOL NICE WEATHER.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 42 51 43 73 55 / 50 30 5 5 10
WACO, TX 44 52 44 75 56 / 70 30 5 5 10
PARIS, TX 38 46 41 68 49 / 40 60 10 5 10
DENTON, TX 40 51 41 72 55 / 40 30 5 5 10
MCKINNEY, TX 41 49 41 72 54 / 40 40 5 5 10
DALLAS, TX 42 50 46 73 56 / 60 40 5 5 10
TERRELL, TX 41 49 44 74 55 / 70 50 5 5 10
CORSICANA, TX 42 49 44 73 57 / 90 60 5 5 10
TEMPLE, TX 43 53 44 76 56 / 80 20 5 5 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
