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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS64 KFWD 250847
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
347 AM CDT SAT MAY 25 2013

.DISCUSSION...
-- Changed Discussion --
RADAR/SATELLITE LOOP INDICATES THAT THE WEAK MID LEVEL LOW IS
LIKELY LOCATED NEAR ABILENE AND 00Z 500MB ANALYSIS CONFIRMS IT IS
WARM-CORE IN NATURE. AS IS OFTEN THE CASE WITH WARM-CORE
LOWS...CONVECTION IS FIRING BEFORE SUNRISE ACROSS THE HILL
COUNTRY WITHIN A WEAK LOW LEVEL JET AXIS WHERE THETA-E ADVECTION
AND OROGRAPHIC LIFT ARE OCCURRING. SHORT-TERM MODELS SUCH AS THE
HRRR AND RUC SUGGEST THAT SCATTERED CONVECTION WILL CONTINUE TO
EXPAND NORTHWARD FROM CENTRAL TEXAS INTO THE WESTERN ZONES DURING
THE MORNING HOURS. THE GFS APPEARS TO BE SUFFERING FROM GRID SCALE
CONVECTIVE FEEDBACK WHICH IS RESULTING IN VERY HIGH QPF AND
CONTAMINATED MASS FIELDS...THUS THE GFS WILL NOT BE USED IN THE
SHORT-TERM. THE NAM SEEMS TO BE MATCHING CURRENT TRENDS AND SHORT-
TERM MODELS WELL AND THEREFORE IT GIVES CONFIDENCE TO RAISE POPS
TODAY. WE EXPECT THE BEST COVERAGE OF CONVECTION IN THE WESTERN
ZONES THIS MORNING. SCATTERED CONVECTION WILL BUILD/EXPAND
EASTWARD INTO THE EASTERN ZONES DURING THE MIDDAY/AFTERNOON HOURS.
THE AIRMASS OVER THE EASTERN ZONES WILL BE A BIT MORE UNSTABLE DUE
TO BETTER INSOLATION AND A COUPLE OF STRONG STORMS WITH GUSTY
WINDS WILL BE POSSIBLE...BUT DUE TO WEAK SHEAR THE SEVERE THREAT
IS LOW. HIGHS TODAY IN THE WESTERN ZONES WILL ONLY BE IN THE UPPER
70S TO LOW 80S DUE TO CLOUDS/RAIN...WITH HIGHS IN THE EASTERN
ZONES REACHING THE MID 80S. SCATTERED CONVECTION WILL CONTINUE
INTO THE EVENING HOURS BEFORE DISSIPATING WITH LOSS OF HEATING.

THE WARM CORE MID LEVEL LOW WILL BE EXITING THE REGION TO THE
NORTHEAST TONIGHT...AND THEREFORE THE RAIN CHANCES WILL COME TO AN
END. EXPECT A DRY SUNDAY WITH TEMPERATURES REBOUNDING INTO THE
MID-UPPER 80S AREA WIDE. AS AN UPPER LEVEL TROUGH DEVELOPS ACROSS
THE INTER-MOUNTAIN WEST...A SURFACE LOW WILL DEEPEN IN THE HIGH
PLAINS MONDAY. THIS WILL BRING BREEZY SOUTH WINDS TO THE REGION
MONDAY WHICH WILL LIKELY PERSIST THROUGH THE WEEK. LOW TEMPS WILL
WARM INTO THE 70S AREA WIDE BY MIDWEEK WITH HIGHS GENERALLY IN THE
MID 80S EAST TO LOW 90S WEST. THE SOUTHWEST FLOW ABOVE THE
SURFACE WILL BRING A THERMAL INVERSION INTO THE AREA. THUS THE
FORECAST LOOKS DRY UNLESS/UNTIL FORCING ARRIVES TO WEAKEN THE CAP.

MODEL GUIDANCE REMAINS IN POOR TO FAIR AGREEMENT REGARDING THE
EVOLUTION/EJECTION OF THE WEST COAST UPPER TROUGH MID-LATE WEEK.
THE ECMWF CONTINUES TO SHOW A VERY NEGATIVELY TILTED TROUGH
SWINGING THROUGH THE REGION LATE WEDNESDAY AND THURSDAY WHICH
WOULD BODE WELL FOR RAIN. BUT IT CONTINUES TO BE THE ONLY MODEL
THAT SHOWS THE TROUGH EJECTION LIKE THIS...AND FRANKLY THE 500MB
PATTERN IT PRESENTS JUST DOES NOT LOOK REALISTIC. IF IT WERE NOT
FOR THE ECMWF BEING THE BETTER OF THE LONG RANGE MODELS...I WOULD
DISCOUNT IT ALTOGETHER AND SHOW A DRY FORECAST ON THURSDAY...BUT
FOR NOW HAVE RETAINED THE SLIGHT CHANCE POPS. THE GFS/UKMET/GEM
FORECASTS SHOW THAT THE UPPER ENERGY NEEDED TO BREAK THE CAP WILL
LIKELY REMAIN WELL NORTHWEST OF THE REGION. FURTHERMORE...THE
DRYLINE ALSO LOOKS LIKE IT WILL REMAIN TOO FAR TO THE WEST...WITH
THE GFS SHOWING IT AS FAR WEST AS THE TX PANHANDLE. STORM MOTIONS
WILL GENERALLY BE NORTHEAST AND THIS MEANS STORMS WOULD NOT EVEN
HAVE A CHANCE TO PROPAGATE INTO THE CWA EITHER. SO IN SUMMARY THE
RAIN CHANCES ON THURSDAY AT THIS POINT ARE HINGING ON THE ECMWF
BEING CORRECT...AND THIS MAY BE A BIT OF A LONG SHOT.

TR.92
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&&

.PRELIMINARY POINT TEMPS/POPS...
-- Changed Discussion --
DALLAS-FT. WORTH, TX  84  69  87  69  87 /  40  30  10   5   0
WACO, TX              83  68  87  68  89 /  50  30  10   5   0
PARIS, TX             83  67  85  66  85 /  30  30  10   5   0
DENTON, TX            85  67  86  68  87 /  40  30  10   5   0
MCKINNEY, TX          84  67  85  68  87 /  30  30  10   5   0
DALLAS, TX            85  71  87  70  89 /  30  30  10   5   0
TERRELL, TX           84  67  86  68  88 /  30  30  10   5   0
CORSICANA, TX         84  67  88  68  89 /  30  30  10   5   0
TEMPLE, TX            82  67  87  68  88 /  50  20  10   5   0
MINERAL WELLS, TX     81  66  87  67  89 /  40  20  10   5   0
-- End Changed Discussion --

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$