000
FXUS64 KBRO 100803
AFDBRO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
303 AM CDT FRI OCT 10 2008

.DISCUSSION...THOUGH THE WEATHER TODAY WILL REFLECT PERSISTENCE...
CONDITIONS WILL DRIFT TOWARD UNSETTLED OVER THE WEEKEND. AFTER A
BRIEF...THOUGH NOT COMPLETE...RECOVERY EARLY IN THE WEEK...MORE
UNSETTLED WEATHER WILL BE BACK FOR THE SECOND HALF OF NEXT WEEK.

THE ABOVE IS A QUICK...THOUGH GENERAL...SUMMARY OF WHAT IS TO COME.
THOUGH TEMPERATURES ARE EXPECTED TO BE RATHER STABLE AT SLIGHTLY
WARMER THAN NORMAL THROUGH THE FORECAST...IT WILL IN FACT BE A
SOMEWHAT TRICKY FORECAST FROM A PRECIPITATION STANDPOINT DUE TO A
NUMBER OF COMPLICATING FACTORS.

INITIALLY AND IN THE SHORT TERM...A SIMPLE INCREASE IN MOISTURE FROM
THE SOUTHEAST WILL BE EVIDENT. H5 RIDGING AND HIGH PRESSURE OVER THE
SOUTHEAST UNITED STATES WILL PROVIDE THE FLOW...ALREADY ESTABLISHED
ALTHOUGH STILL WEAK. MOISTURE WILL INCREASE MODESTLY THROUGH EARLY
SATURDAY...BUT FORECAST SOUNDINGS SHOW AN INCREASE IN PWAT TO ABOVE
TWO INCHES BY SATURDAY AFTERNOON...THEN REMAINING HIGH THROUGH EARLY
MONDAY MORNING. LOW LEVEL INSTABILITY WILL BE THE ONLY MECHANISM TO
FUEL CONVECTION...WHICH WILL CONSIST MAINLY OF SHOWERS MOVING ASHORE
FROM THE GULF...SOME REACHING THE MID VALLEY.

THE NEXT FEATURE OF CONCERN WILL BE A SLOWLY DEEPENING H5 TROUGH
OVER THE WEST INCLUDING THE GREAT BASIN AND FOUR CORNERS AREA. A
STORM SYSTEM WILL EJECT NORTHEAST OUT OF THIS FEATURE INTO THE
PLAINS ON SATURDAY AND SUNDAY...BUT MID LEVEL MOISTURE IS GOING TO
CONTINUE TO PUMP INTO WEST TEXAS AROUND THE BASE OF THE TROUGH...
FEEDING IN FROM HURRICANE NORBERT IN THE EAST PACIFIC. WHILE HEAVY
RAINFALL WILL DEVELOP OVER WEST TEXAS ALONG A SOUTHWEST TO
NORTHEAST LINE BETWEEN BETWEEN RIDGING TO THE EAST AND TROUGHING
TO THE WEST...MOST OF NORBERT`S MOISTURE MAY NOT HAVE MUCH OF A
ROLE FOR DEEP SOUTH TEXAS. ON THE OTHER HAND...TROPICAL STORM
ODILE WILL MOVE UP THE WEST MEXICAN COAST AND COULD END UP BEING
THE MORE IMPORTANT MID LEVEL MOISTURE SOURCE.

IN ANY CASE...THE WEST GULF IS GOING TO BECOME VERY UNSETTLED BY THE
MIDDLE OF NEXT WEEK...AND THE COASTAL AREAS OF DEEP SOUTH TEXAS WILL
ESPECIALLY NOTICE PERSISTENT...SHOWERY WEATHER. THE MODELS DO NOT
SUGGEST INCIPIENT TROPICAL ACTIVITY IN THE GULF DURING THIS PERIOD
HOWEVER.

IN THE MEAN TIME...THE H5 TROUGH OVER THE WEST WILL BREAK DOWN AND
SHIFT EAST FROM THE EARLY TO MIDDLE PART OF NEXT WEEK. A FRONTAL
BOUNDARY COULD PUSH SOUTHEAST TO INTERACT WITH GULF MOISTURE ON
WEDNESDAY...POTENTIALLY SETTING UP A HEAVY LOCAL RAIN SCENARIO FOR
THE LATTER HALF OF THE WEEK. LINGERING UNSETTLED WEATHER FROM THIS
EVENT COULD EASILY PERSIST INTO THURSDAY AND FRIDAY OF NEXT WEEK.

THE FORECAST WILL REFLECT SOMEWHAT HIGHER POPS THAN TYPICAL FOR THE
LONG TERM...BUT EVEN THOUGH THERE IS SOME UNCERTAINTY IN THE EXACT
DETAILS AT THIS POINT...BELIEVE THAT THE OVERALL SYNOPTIC SITUATION
JUSTIFIES THE HIGHER NUMBERS.
&&

.PREV DISCUSSION... /ISSUED 800 PM CDT THU OCT 9 2008/ A DRY AND
STABLE AIRMASS WILL CONTINUE THROUGH SATURDAY AS HIGH PRESSURE
WILL DOMINATE. HIGH PRESSURE WILL MOVE EAST BY SUNDAY CAUSING A
SOUTHEAST FLOW OF AIR AND MOISTURE TO RETURN. ISOLATED SHOWERS ARE
POSSIBLE SUNDAY AND MONDAY OF NEXT WEEK. A COLD FRONT WILL MOVE
THROUGH THE AREA BY LATE TUESDAY CAUSING A GOOD CHANCE FOR SHOWERS
OR THUNDERSTORMS. A DRIER AND MORE STABLE AIRMASS COULD BE IN
STORE FOR THE AREA BY NEXT WEEKEND. PREVIOUS FORECAST PACKAGE
LOOKS GOOD AT THIS TIME. NO UPDATES NEEDED AT THIS TIME.
&&

.MARINE...BUOY020 REPORTS AN ESE WIND FROM 10 TO 15 KTS WITH SWELLS
AROUND 2 FT WITH MTRPIL REPORTING A SE WIND AROUND 5 KTS. A FAIRLY
STRONG SURFACE RIDGE PREVAILING OVER THE EASTERN U.S. WITH COMBINE
WITH A SURFACE LOW PRESSURE AREA DEVELOPING OVER THE MIDDLE SECTIONS
OF THE COUNTRY TO SLOWLY TIGHTEN UP THE PGF ALONG THE LOWER TX
COASTLINE LATER THIS UPCOMING WEEK. A COLD FRONT WILL SAG TOWARDS
THE GULF COAST TOWARDS THE END OF NEXT WEEK WHICH MAY BUILD THE
OVERALL SWELLS A BIT LATER IN THE CWF PERIOD. THE CURRENT TREND OF
THE CWF WORDING LOOKS ON TRACK WITH NO MAJOR CHANGES NEEDED.
&&

.AVIATION...THE CURRENT SURFACE OBS AND IR SATL SHOWS CLEAR SKIES
AROUND THE REGION EARLY THIS MORNING.  THE SE SURFACE FLOW WILL
RETURN LATER TODAY INCREASING THE LOW LEVEL DEW POINTS AROUND THE
LOWER RGV AIRPORTS. THIS WILL COMBINE WITH THE INCREASING DAYTIME
HEATING LATER THIS AFTERNOON TO HELP PRODUCE SOME SCT SC CLD DECKS.
EXPECT VFR CONDITIONS TO PREVAIL FOR THIS CURRENT TAF PERIOD.
&&

.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL  87  76  89  77 /   0  10  50  50
BROWNSVILLE          88  75  90  75 /   0  10  80  70
HARLINGEN            90  72  91  75 /   0  10  50  50
MCALLEN              90  74  91  75 /   0  10  40  40
RIO GRANDE CITY      90  71  91  73 /   0  10  30  30
SOUTH PADRE ISLAND   86  75  87  78 /   0  10  50  40

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&

$$

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

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