Severe Thunderstorm Warning 9, NWS Brownsville, TX

DEEP SOUTH TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
250 PM CST SUN FEB 01 1998

WILL MAKE THE DISC BRIEF AS CURRENTLY IN THE PROCESS OF ISSUING
WARNINGS.   CURRENT CONDITIONS AND MESO DISC...CURRENT KBRO
REFLECTIVITY SHOWS WELL DEVELOPED AREA OF CONV OVER EASTERN STARR
AND JIM HOGG COUNTIES.  AREAL COVERAGE IS TO THE EAST AT AROUND 15
MPH WHILE CELLULAR MOVEMENT IS TO THE NORTHEAST AT 15 TO 20 MPH. SO
FAR SPOTTER REPORTS HAVE SHOWN ONLY HAIL SIZES JUST BELOW SEVERE
LIMITS...HOWEVER VIL VALUES REMAIN HIGH AND A COUPLE OF WEAK MESOS
HAVE BEEN DETECTED. CURRENT CONV IS ALSO TRACKING THROUGH FIELD OF
-8 LI/S AND NIL CAPPING AS SHOWN BY ADAP CHARTS.  ADAP ALSO SHOWS
SIGNIFICANT SURFACE MOISTURE CONVERGENCE ACROSS FORECAST AREA WHICH
WILL ALSO ENHANCE CONV.  LASTLY...THE LATEST MTR FROM BRO...HRL AND
MFE ALL SHOW PRESFR WHICH JIVES WELL WITH ADAP PRESSURE FALLS.  SO
AGREE WITH AGREE WITH THE LATEST WWAMKC FROM SPC IN CONTINUING
WATCH.

THE NEXT QUESTION WILL BE WHETHER CONV WILL REDEVELOP AFTER THE
FIRST LINE MOVES OFFSHORE.  WITH THE LOSS OF THE DAYTIME HEATING
AND THE STABILIZATION CAUSED BY THE OUTFLOW FROM THE CURRENT
CONV...THIS SHOULD LIMIT CONV POTENTIAL LATE THIS AFTERNOON AND
TONIGHT.  IN ADDITION...AVN GUIDANCE SHOWS JET JUST SOUTH OF THE
REGION SLOWLY WEAKENING.  HOWEVER...THE LATEST OB FROM LRD SHOWS A
GOOD NORTHWEST SURFACE FLOW...AND THIS SHOULD FOLLOW QUICKLY ON THE
HEELS OF THE CURRENT CONV ADVECTING COOLER AND DRIER AIR INTO THE
REGION.

SO WILL ADJUST WORDING OF THE 1ST PD TO MENTION EARLY EVENING CONV
WITH NIL POPS AFTER WINDS SHIFT.

WILL THEN FOLLOW MOS SKY...TEMP AND WIND GUIDANCE AS THE NORTHERN
GULF SYSTEM SLOWLY SHIFTS AWAY FROM THE TX COAST AND COOLER AND
DRIER AIR AVECTS SOUTHWARDS.

FOR TXZ248>255...

.TONIGHT...(SVR WATCH UNTIL 600 PM) MOSTLY CLOUDY WITH A 40 % CHC
FOR EARLY EVENING RW/TRW...SOME PRODUCING LARGE HAIL AND DAMAGING
THUNDERSTORM WINDS.  THEN DECREASING CLOUDS AND BECOMING WINDY LATE
EVENING.  GUSTY SOUTHEAST WINDS 15 TO 20 MPH EARLY...THEN BECOMING
NORTHWEST AND INCREASING TO 15 TO 25 MPH.

.MON...MOSTLY SUNNY AND WINDY.  NW WINDS 15 TO 25 MPH.

.MON NIGHT...MOSTLY CLEAR AND BREEZY.

.TUES...MOSTLY SUNNY.

CWF...AGREE WITH SAT ON PUTTING UP A GALE WARNING AS BOUNDARY LAYER
WINDS MAINTAIN A N-NW FLOW OVER THE WESTERN GULF AT 25 TO 30 KNOTS.
SO GALE WARNING LOOKS GOOD THROUGH ALL THREE PERIODS.

BRO UU 053/074 043/076 045 40/00/00/00
MFE UU 053/075 042/077 044 40/00/00/00
RGC UU 050/075 040/078 043 40/00/00/00
SPI UU 058/070 050/072 052 40/00/00/00

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