Flash Flood Warning 42, NWS Brownsville, TX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
1208 AM CDT SUN OCT 12 2003

...ADDED FFA FOR ALL OF THE RGV...

.DISCUSSION...STLT IR PICS SHOW SUM OF THE COLDEST CLD TOPS EVER
SEEN OVR WRN VLY. COPIOUS RAFL IMMINENT...WITH FFW ISSUED FOR WEBB
NOW. ALL MDLS PAINT HIGH RAFL TOTALS FOR DEEP S TXX TDY...WITH
EXCESSIVE RAFL OUTLOOK ISSUED BY HPC AT 0117Z PLACING WRN AND NRN
VLY IN MAX RAFL POTENTIAL OF 5 INCHES 03Z TDY THRU 00Z
MON.

WILL PLACE ALL OF RGV UNDER FLASH FLOOD WATCH IMMEDIATELY.
&&

.PREV DISCUSSION OF 215 PM CDT SAT OCT 11 2003....SYNOPSIS...A
MOSTLY CLOUDY SKY WITH AFTERNOON SHOWERS AND THUNDERSTORMS COVERED
PARTS OF DEEP SOUTH TEXAS. THESE SHOWERS AND THUNDERSTORMS DEVELOPED
AND MOVE ACROSS THE EASTERN AND MIDDLE COUNTIES. THE HEAVIEST
RAINFALL FELL OVER SOUTHWESTERN WILLACY AND CENTRAL HIDALGO
COUNTIES. TEMPERATURES THIS AFTERNOON CLIMBED TO THE UPPER 80S TO
LOWER 90S. AN EAST TO SOUTHEAST WIND OF 10 TO 20 MPH PREVAILED.

UNSTABLE TROPICAL MOISTURE BEING PUSHED ASHORE BY AN EAST WIND WILL
COMBINE WITH A COLD FRONT APPROACHING THE RIO GRANDE ON SUNDAY.
THESE TWO COMBINATIONS WILL INCREASE THE THREATS OF NUMEROUS SHOWER
ACTIVITY THROUGH THE HOLIDAY WEEKEND.
&&

.MARINE...SEAS 3 FEET OFFSHORE WITH EAST WINDS NEAR 15 KNOTS. 500MB
RIDGE OVER THE WESTERN GULF OF MEXICO CONTINUES TO KEEP BULK OF
CONVECTION ACROSS NORTHERN MEXICO INTO THE RIO GRANDE PLAINS. EXPECT
LIGHT TO MODERATE EAST WINDS TO PREVAIL AS A WEAK COLD FRONT OVER
NORTH TX SAGS INTO CENTRAL TX TONIGHT. 18Z MESOETA PROGS ISOLATED TO
SCATTERED CONVECTION DEVELOPING OVER THE COASTAL WATERS AFTER
MIDNIGHT. OUTFLOW FROM CONVECTION OVER THE RIO GRANDE PLAINS MAY
DRIFT INTO THE COASTAL WATERS PROVIDING A FOCUS FOR LOW LEVEL
CONVERGENCE. WILL UPDATE CWF TO REFLECT CONVECTIVE TREND.
&&

.AVIATION...SHOWERS AND THUNDERSTORMS WILL IMPACT THE LOWER RIO
GRANDE VALLEY TOMORROW AS A CONVECTIVE BOUNDARY OVER THE HILL
COUNTRY MOVES SOUTH. EXPECT VFR TO MVFR CONDITIONS WITH SHOWERS AND
THUNDERSTORMS IN THE VICINITY OF TERMINAL AERODROMES.
BROWNSVILLE DOPPLER
RADAR DEPICTS ISOLATED SHOWERS MOVING OVER PORTIONS OF THE CWA THIS
AFTERNOON. EXPECT ISOLATED TO SCATTERED SHOWERS WITH A FEW EMBEDDED
THUNDERSTORMS TO CONTINUE TO DEVELOP THIS AFTERNOON AND EVENING AS
THE ATMOSPHERE REMAINS MOIST ACROSS THE CWA. OVERNIGHT AREAS OF FOG
MAY DEVELOP OVER PORTIONS OF THE CWA AS THE ATMOSPHERE REMAINS MOIST
AND LIGHT WINDS ARE EXPECTED. LIGHT TO MODERATE EASTERLY WINDS WHICH
ARE OCCURRING OVER DEEP SOUTH TEXAS THIS AFTERNOON SHOULD CONTINUE
THROUGH SUNDAY. PRECIPITATION CHANCES ARE EXPECTED TO INCREASE
SUNDAY AS A WEAK COLD FRONT APPROACHES THE CWA AND STALLS TO THE
NORTH OF DEEP SOUTH TEXAS ON MONDAY.

LONG TERM...CHANCES FOR PRECIPITATION IS EXPECTED TO CONTINUE
THROUGH FRIDAY WHEN A SERIES OF COLD FRONTS ARE EXPECTED TO MOVE
THROUGH DEEP SOUTH TEXAS. THE APPROACHING FRONTAL BOUNDARIES WILL
RESULT IN INCREASED WINDS ACROSS THE CWA EARLY IN THE WEEK. A COLD
FRONT SHOULD MOVE ACROSS DEEP SOUTH TEXAS FRIDAY SETTING THE STAGE
FOR A DRIER PERIOD AND SLIGHTLY COOLER TEMPERATURES.
&&

.BRO WATCHES/WARNINGS/ADVISORIES...FFA TXZ248>257.
&&

58/59/

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HTTP://WWW.SRH.NOAA.GOV/BRO

TXZ248>257-121100-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BROWNSVILLE TX
1249 AM CDT SUN OCT 12 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR DEEP SOUTH TEXAS.

.DAY ONE..TONIGHT.

A FLASH FLOOD WATCH IS IN EFFECT TONIGHT FOR ALL OF DEEP SOUTH TEXAS
UNTIL 5 PM SUNDAY. NUMEROUS THUNDERSTORMS WITH HEAVY RAINFALL
ARE EXPECTED TO CONTINUE THROUGH THIS AFTERNOON. RAINFALL AMOUNTS
WILL AVERAGE 1 TO 2 INCHES WITH ISOLATED AMOUNTS UP TO 4 INCHES
POSSIBLE...ESPECIALLY IN THE WESTERN VALLEY.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

STRONG THUNDERSTORMS WITH VERY HEAVY RAINFALL ARE FORECAST FOR
SUNDAY THROUGH MONDAY...AS A SLOW MOVING COLD FRONT LIFTS THE MOIST
AND UNSTABLE AIRMASS OVER OUR REGION. SOME OF THESE THUNDERSTORMS
COULD BECOME SEVERE...WITH STRONG GUSTY WINDS...SMALL
HAIL...FREQUENT LIGHTNING AND VERY HEAVY RAINFALL. TEMPERATURES
SHOULD ONLY REACH THE UPPER 70S SUNDAY AND MONDAY...WITH MORNING
LOWS IN THE 60S. A STRONGER COLD FRONT WILL MOVE THROUGH OUR REGION
THURSDAY...BRINGING MORE HEAVY RAINS...STRONG NORTH WINDS AND COOLER
TEMPERATURES FOR NEXT WEEKEND.

.SPOTTER INFORMATION STATEMENT.

SPOTTER ACTIVATION IS LIKELY TODAY...TONIGHT AND TOMORROW.

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