FXUS64 KBRO 090912
AFDBRO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
245 AM CST WED DEC 9 2009

.DISCUSSION...A WEAK BOUNDARY JUST NORTH OF THE LOWER VALLEY WILL 
SLOWLY MOVE SOUTH AND STALL IN THE AREA THIS MORNING.  A STRONG COLD 
FRONT WILL MOVE THROUGH DEEP SOUTH TEXAS BY MIDDAY TODAY CAUSING 
COOLER TEMPERATURES...CLOUDY SKIES AND NORTH WINDS IN ITS WAKE.  
OVERRUNNING TYPE LIGHT RAIN OR DRIZZLE COULD DEVELOP LATER TONIGHT 
AND CONTINUE THROUGH THE END OF THE WEEK.  A WEST TO SOUTHWEST FLOW 
ALOFT COMBINED WITH SHALLOW COOL AIR AT THE SURFACE WILL SETUP THIS 
OVERRUNNING SITUATION.  WINDS WILL CONTINUE TO BE OUT OF THE NORTH 
BOTH THURSDAY AND FRIDAY WITH TEMPERATURES IN THE 50S AND 60S.  THE 
AIRMASS WILL SLOWLY MODIFY BY THE WEEKEND WITH CONTINUE COOL 
TEMPERATURES ON SATURDAY BEFORE WARMING INTO THE 70S ON SUNDAY.  THE 
WINDS WILL FINALLY SWITCH FROM THE SOUTH AND QUITE GUSTY ON MONDAY 
CAUSING HIGH TEMPERATURES TO BE IN THE 80S.  ANOTHER COLD FRONT 
WILL MOVE THROUGH THE AREA ON TUESDAY CAUSING COOLER TEMPERATURES 
ONCE AGAIN TUESDAY AND TUESDAY NIGHT.    
&&

.MARINE...THE 2 AM OBSERVATION FROM BUOY020 INDICATED WINDS WERE 
SOUTH SOUTHWEST AROUND 4 KTS AND SEAS WERE AROUND 6 FT WITH A PERIOD 
OF 8 SECONDS. AGITATED MARINE CONDITIONS EXPECTED TO DEVELOP TDA 
ACROSS THE LOWER TX COASTAL WATERS AS A FRONTAL BOUNDARY PUSHES THRU 
THE AREA. SOUTHERLY WINDS ANTICIPATED THRU THE EARLY MRNG BEFORE 
INITIAL SURGE OF NORTHERLY FLOW AND PRE FRONTAL TROF SLIDE THRU 
AROUND THE SUNRISE HRS. WINDS BECOME NORTHERLY AND INCREASE THRU THE 
MRNG HRS AS SEAS GRADUALLY BUILD. SCA CONDITIONS EXPECTED TO DEVELOP 
THIS MRNG ACROSS OUR NEARSHORE AND OFFSHORE GULF OF MEXICO WATERS. 
THEREFORE...WILL BE ISSUING A SMALL CRAFT ADVISORY BEGINNING AT 9 AM 
CDT. A SECONDARY SURGE WITH THE ACTUAL COLD FRONT AND ASSOC CAA WILL 
PUSH THRU LATER THIS AFTN REINFORCING THE NORTHERLY FLOW AND ALLOW 
THE STRONGER WINDS AND ELEVATED SEAS TO PERSIST. THE SCA CONDITIONS 
ARE EXPECTED TO CONTINUE THRU TNGT AND AT LEAST INTO THU MRNG.

A TIGHT PRESSURE GRADIENT BETWEEN HIGH PRESSURE TO THE NORTH AND LOW 
PRESSURE TO OUR SE IN THE WESTERN GULF OF MEXICO WILL PERSIST ON THU 
INTO EARLY FRI. MODERATE TO STRONG NE TO E FLOW WILL CONTINUE THRU 
THIS TIME WHICH WILL MAKE FOR PERSISTENT UNSETTLED CONDITIONS ACROSS 
OUR COASTAL WATERS. BY LATE FRI INTO SAT...LOW PRESSURE WILL HAVE 
SLIDE ACROSS OUR MARINE ZONES AND WILL MOVE NEWD INTO THE CENTRAL 
GULF OF MEXICO. THE PRESSURE GRADIENT WILL RELAX ALLOWING WINDS TO 
DIMINISH AND SEAS TO SUBSIDE IN TIME FOR THE WEEKEND. THE UNSETTLED 
CONDITIONS WITH THE FROPA TDA AND LOW PRESSURE NEARBY ON FRI WILL 
CREATE THE POTENTIAL FOR SOME LIGHT PCPN LATER TDA THRU EARLY SAT.
&&

.AVIATION...THE 3 LOCAL TAF SITES ARE REPORTING REDUCED CIGS AND 
VSBYS DUE TO FOGGY CONDITIONS THAT HAVE DEVELOPED EARLY THIS MRNG. 
LIFR CIGS AND MVFR TO IFR VSBYS ARE PREVAILING AT THE TERMINALS. THE 
FOG AND LOW CIGS ARE LIKELY TO REMAIN PERSISTENT THRU THE SUNRISE 
HRS TDA. IMPROVING CONDITIONS ARE ANTICIPATED AS A FRONTAL BOUNDARY 
IS EXPECTED TO PASS THRU THE AREA TDA. SOUTHERLY WINDS THRU EARLY 
MRNG WILL SWITCH TO THE NORTH AS A PRE FRONTAL TROF PUSHES THRU. 
THIS WIND SHIFT LINE SHUD HELP TO SCOUR OUT THE FOG WITH IMPROVING 
VSBYS BY MID MRNG. THE LOW CIGS WILL CONTINUE INTO MID MRNG BUT 
BEGIN TO RISE THEREAFTER WITH VFR CONDITIONS ANTICIPATED TWD MIDDAY.
&&

.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL  70  53  61  52 /  10  10  20  40 
BROWNSVILLE          72  52  60  52 /  10  10  20  40 
HARLINGEN            69  48  57  52 /  10  10  20  40 
MCALLEN              73  49  57  50 /  10  10  20  40 
RIO GRANDE CITY      69  47  56  46 /  10  10  20  40 
SOUTH PADRE ISLAND   71  53  63  53 /  10  10  20  40 
&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY FROM 9 AM THIS MORNING TO 6 AM CST         
     THURSDAY FOR GMZ150-155-170-175.  
&&

$$

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

SYNOPTIC/GRIDS...65
MARINE/AVIATION/MESO...57