871
AWUS01 KWNH 240204
FFGMPD
TXZ000-OKZ000-240700-
MESOSCALE PRECIPITATION DISCUSSION 1203
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1003 PM EDT THU OCT 23 2025
AREAS AFFECTED...TEXAS BIG COUNTRY...
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE
VALID 240200Z - 240700Z
SUMMARY...SHORT WINDOW OF VERY INTENSE SLOW MOVING CELLS BEFORE
FORWARD PROPAGATION BEGINS. NARROW AXES OF TRAINING/REPEATING ARE
POSSIBLE ACROSS SMALL AREA OF NATURALLY LOWER FF VALUES. WIDELY
SCATTERED FLASH FLOODING REMAINS POSSIBLE FOR THE NEXT FEW HOURS.
DISCUSSION...A WELL DEFINED SURFACE TO BOUNDARY LAYER
CONVERGENCE/FRONTAL ZONE WAS NOTED EXTENDING EAST-NORTHEAST
GENERALLY ALONG I-20 FROM A SURFACE LOW NEAR FT. STOCKTON UP TO
ABOUT KRPH. WINDS HAD AN EASTERLY COMPONENT FURTHER STRENGTHENING
MOISTURE FLUX CONVERGENCE AS SOUTHERLY FLOW OFF THE WESTERN GULF
HAS BEEN IN THE MID TO UPPER 50S FOR TDS WITH LOW TO MID 60S
FURTHER EASTWARD WHERE LARGER SYNOPTIC CONTINENTAL POLAR AIR
REMAINS LOCKED THE MIDDLE MISSISSIPPI TO TENNESSEE VALLEYS. THE
HIGHER THETA-E AIR POOLED ALONG THE OLD BOUNDARY SHOWED A SOLID
AXIS OF ENHANCED 1000-1500 J/KG OF CAPE. POLAR JET EXIT HAS BEEN
ADVANCING OUT OF THE SOUTHERN HIGH PLAINS WITH FAVORABLE LEFT EXIT
ASCENT IN THE VICINITY OF THE CONVERGENCE AS WELL AS THE TRAILING
POSITIVE TILT MID-LEVEL TROUGH AXIS REMAINED OVER FAR NW TEXAS AS
THE WAVE LIFTS THROUGH CENTRAL OK.
AS A RESULT, STRONG VERTICAL ASCENT AND SCATTERED TO NUMEROUS
UPDRAFTS WERE NOTED ALONG THE OLD FRONTAL ZONE WITH BROADENING
COOLING TOPS FALLING BELOW -65C NEARING -70C; DENOTING THE INITIAL
VIGOR TO THE UPDRAFTS. THE STRONG MOISTURE FLUX AS RESULTED IN
BROADENING UP/DOWNDRAFT CORES AND EFFICIENT RAINFALL AND SMALL
HAIL RESULTING IN LOCALIZED 1.5-2"/HR RATES. A FEW SPOTS HAVE
ALREADY EXPERIENCED THESE TOTALS WITH AN 1-2" MORE POSSIBLE.
SLOW FORWARD MOTIONS WERE A RESULT OF THE LINGERING NORTHEASTERLY
FLOW AND ANCHOR TO THE OLD BOUNDARY; HOWEVER, AS THE NOCTURNAL LOW
LEVEL JET IS STARTING TO DEVELOP, THE EASTERLY COMPONENT AREAS
HAVE BEEN OVER-RUN AND BROAD/STRENGTHENING SOUTH TO SOUTHEASTERLY
FLOW HAS TAKEN OVER. THIS WILL ALLOW FOR EVENTUAL EASTWARD
PROPAGATION ON THE DEVELOPMENT OF WEAK COLD POOLS.
ORIENTATION OF THE BOUNDARY IS FAIRLY PARALLEL TO THE DEEPENING
UNIDIRECTIONAL STEERING FLOW OUT OF THE WEST-SOUTHWEST. INITIALLY
ABOUT 10-15KT, STEERING FLOW WILL INCREASE TO 20-30+KTS OVER THE
NEXT FEW HOURS LIKELY TO REDUCE THE POTENTIAL FOR LARGER RAINFALL
TOTALS AND LIMIT RISK OF FLASH FLOODING DUE TO THE INITIAL BURST
OF UP TO 1-1.25" IN 15-30 MINUTES OVERWHELMING THE DRIER GROUNDS
WITH LIMITED INFILTRATION. AS SUCH, LOCALIZED FLASH FLOODING
WILL SHIFT TOWARD WIDELY SCATTERED AND MORE LIKELY LIMITED TO
PRONE OR URBAN/LOW INFILTRATION GROUND CONDITIONS ACROSS THE BIG
COUNTRY THROUGH THE EARLY OVERNIGHT PERIOD.
GALLINA
..PLEASE SEE WWW.WPC.NCEP.NOAA.GOV FOR GRAPHIC PRODUCT
ATTN...WFO...FWD...LUB...MAF...OUN...SJT...
ATTN...RFC...FWR...TUA...NWC...
LAT...LON 34189748 33789695 33039732 32689782 32399844
32169959 31840075 31610177 32030223 32750153
33410038 33759932
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