Flash Flood Warning 103, NWS Brownsville, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
149 PM CDT FRI JUL 27 2007

.DISCUSSION...AFTERNOON CONCERNS WILL BE CONCENTRATING ON PLACEMENT
AND POSSIBLE EXTENSION OF THE FLASH FLOOD WATCH BEYOND 7 PM. A
COASTAL SURFACE LOW PRESSURE TROUGH HAS BEEN THE FOCUS OF
THUNDERSTORM DEVELOPMENT THIS MORNING AND EARLY AFTERNOON. THE
STORMS HAVE BEEN SLOWLY BACK BUILDING SOUTHWEST ALONG THE TROUGH
WITH THE ASSISTANCE OF A STRONG UPPER DISTURBANCE ROUNDING THE
SOUTH END OF THE MID UPPER LOW THAT IS CENTERED OVER WEST CENTRAL
TEXAS. EXPECT THE COASTAL COUNTIES OF KENEDY...WILLACY AND CAMERON
TO SEE AN INCREASE IN THUNDERSTORMS EARLY IN THE AFTERNOON THEN
THE REMAINDER OF THE CWA ESPECIALLY BROOKS...STARR AND HIDALGO
SHOULD SEE AN INCREASE THROUGH THE LATER HALF OF THE AFTERNOON AND
THIS EVENING. THE COASTAL AREAS COULD SEE THE THUNDERSTORMS
PERSIST INTO THE EVENING AS THE TROUGH COULD TAKE ON A EAST TO
WEST ORIENTATION. WITH THIS MENTION WILL EXTEND THE WATCH UNTIL 10
PM. INITIATION OF THE NAM LOOKED GOOD AND DEPICTED THIS COASTAL
TROUGH BETTER THAN THE GFS. SO WILL BE TRENDING TOWARDS THE NAM
MODEL GUIDANCE WHICH SHOWS A HIGHER CHANCE OF RAIN. LOOKING AT THE
MOISTURE CONTENT...MORNING SOUNDING INDICATED PWS AT 2.33 INCHES
WHICH IS NEAR 150 PERCENT OF NORMAL. FORECAST SOUNDINGS SHOW PWS
TO REMAIN BETWEEN 2.25 AND 2.45 INCHES THROUGH SATURDAY NIGHT AND
STAYING ABOVE 2 INCHES THROUGH SUNDAY. THE MID LEVEL LOW REMAINS
STUCK BETWEEN A HIGH PRESSURE RIDGE OVER THE SOUTHERN ROCKIES AND
THE SUBTROPICAL HIGH OVER THE GULF. CURRENTLY THE LOW SEEMS LIKE
IT IS DRIFTING SLOWLY WEST AND COULD TAKE ON A MORE SOUTHERLY
MOVEMENT TONIGHT AND SATURDAY WHICH SHOULD INCREASE OR MAINTAIN
THE SOUTHERLY FLOW OVER THE CWA FURTHER EVIDENCE OF MAINTAINING
THE HIGHER MOISTURE CONTENT AND HIGHER CHANCE OF RAIN INSTEAD OF
DRYING OUT THE REGION. HAVE RAISED THE POPS TO LIKELY TONIGHT FOR
CENTRAL AND EASTERN COUNTIES AND HIGH END CHANCE FOR SATURDAY AND
MID CHANCE ON SUNDAY SPREADING THE HIGHER POPS EAST TO WEST EACH
DAY. MONDAY DOES LOOK DRIER AT THIS TIME IF THE LOW CONTINUES TO
DRIFT FATHER WESTWARD BUT ADDED LOW END POPS. LEFT THE REMAINDER
OF THE FORECAST PERIOD DRY UNTIL WE SEE WHAT DEVELOPS.
TEMPERATURES WILL BE ADJUSTED DOWNWARD STAYING BELOW NORMAL
THROUGH THE WEEKEND DUE TO THE INCREASE IN POPS...CLOUDS AND
CONTINUED WET SOIL CONDITIONS.

&&

.AVIATION...MAIN CONCERN THIS AFTERNOON IS CONVECTION BUILDING ALONG
THE COAST AND SPREADING INLAND. SHOWERS AND THUNDERSTORMS ARE
EXPECTED TO PERSIST MUCH OF THE AFTERNOON WITH MVFR OR IFR
CONDITIONS IN ANY THUNDERSTORM. SHOWERS MAY CONTINUE OVERNIGHT AND
BECOME MORE SCATTERED BY SATURDAY. WINDS WILL BE GENERALLY LIGHT
THROUGH THE PERIOD.

&&

.MARINE...AT 1PM BUOY 42020 REPORTED NORTH WINDS AT 8 KNOTS AND SEAS
AT 4.6 FEET. SEAS ARE EXPECTED TO REMAIN NEAR PRESENT LEVELS THROUGH
SATURDAY AND THEN SLOWLY DECREASE THROUGH MIDWEEK. WINDS ARE
EXPECTED TO BE GENERALLY LIGHT TO MODERATE THROUGH THE PERIOD.
SHOWERS AND THUNDERSTORMS WILL CONTINUE THE NEXT COUPLE OF DAYS WITH
DRIER CONDITIONS EXPECTED BY EARLY NEXT WEEK.

&&

.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL  79  88  79  89 /  60  40  20  20
BROWNSVILLE          78  91  78  92 /  60  50  20  30
HARLINGEN            77  92  77  92 /  60  50  20  30
MCALLEN              77  93  77  93 /  60  50  20  30
RIO GRANDE CITY      78  93  76  94 /  40  50  30  40
SOUTH PADRE ISLAND   80  88  82  88 /  60  40  20  20

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...FLASH FLOOD WATCH UNTIL 10 PM CDT THIS EVENING FOR TXZ248>257.

&&

THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WWW.WEATHER.GOV/BROWNSVILLE

68/59

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BROWNSVILLE TX
545 AM CDT FRI JUL 27 2007

TXZ248>257-281100-
ZAPATA-JIM HOGG-BROOKS-KENEDY-STARR-HIDALGO-INLAND WILLACY-
INLAND CAMERON-COASTAL WILLACY-COASTAL CAMERON-
545 AM CDT FRI JUL 27 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR DEEP SOUTH TEXAS.

.DAY ONE...TODAY AND TONIGHT

SCATTERED SHOWERS AND THUNDERSTORMS WILL LIKELY REFORM OVER
PORTIONS OF DEEP SOUTH TEXAS LATER TODAY. SOME OF THESE
STRONGER THUNDERSTORMS MAY PRODUCE LOCALIZED HEAVY RAINFALL
THAT COULD RESULT IN THE FLOODING OF CREEKS...STREAMS...ROADS
AND LOW LYING AREAS. AS A RESULT...A FLASH FLOOD WATCH IS IN
EFFECT FOR ALL OF DEEP SOUTH TEXAS THROUGH THIS EVENING.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE
ACROSS PORTIONS OF DEEP SOUTH TEXAS ON SATURDAY AND SUNDAY. HEAT
INDEX READINGS NEXT WEEK WILL INCREASE INTO THE 105 TO 115 DEGREE
RANGE ACROSS MUCH OF THE REGION.  NO OTHER HAZARDOUS WEATHER IS
EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED LATER TODAY.

SPEECE