Area Forecast Discussion
Issued by NWS Brownsville, TX

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000
FXUS64 KBRO 192045
AFDBRO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
245 PM CST WED NOV 19 2014

.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...WINDS...ALBEIT
LIGHT...SHOULD BECOME BETTER ESTABLISHED FROM THE SOUTHEAST TONIGHT.
LOW TEMPS WILL BE IN THE 50S AND 60S WITH MOISTURE AND LOW CLOUDS
MOVING IN FROM THE GULF. THE WARMING TREND WILL CONTINUE ON THURSDAY
WITH HIGH TEMPERATURES IN THE 70S. SOUTHEAST WINDS WILL BECOME LIGHT
TO MODERATE AS THE PRESSURE DROPS UPSTREAM AND HIGH PRESSURE REMAINS
DOMINANT OVER THE NORTHWEST GULF. WILL KEEP A MENTION OF RAIN IN
THROUGH THE SHORT TERM...ISOLATED SHOWERS AT NIGHT AND SCATTERED
THURSDAY AS A WEAK COASTAL TROUGH MAINTAINS SOME INFLUENCE ON NORTH
WARD MVG MOISTURE. ONLY A FEW HUNDREDTHS OF AN INCH OF ACCUMULATION
MAY OCCUR MAINLY NEAR THE COAST ON THURSDAY. LOW TEMPS THURSDAY
NIGHT WILL BE MAINLY IN THE 60S...WITH CONTINUED LIGHT TO MODERATE
SOUTHEAST WINDS AND PARTLY TO MOSTLY CLOUDY SKIES.

.LONG TERM /FRIDAY THROUGH WEDNESDAY/... MAIN ITEM OF FOCUS IN THE LONG
TERM IS A VIGOROUS MID AND UPPER LEVEL STORM SYSTEM PASSING CLOSE
TO THE REGION AND ITS ASSOCIATED IMPACTS. STRONG SOUTHEAST WINDS
WILL LIKELY BEGIN ON FRIDAY AS THIS TROUGH BEGINS DIGGING INTO THE
DESERT SOUTHWEST AND THE LOW LAYER PRESSURE GRADIENT STRENGTHENS
LOCALLY. CONTINUED A SLIGHT CHANCE OF SHOWERS COASTAL/CHANCE OF
SHOWERS OVER THE GULF AS MOIST SOUTHEASTERLY FLOW WORKS OVER THE
LAND/SEA THERMAL GRADIENT ALONG THE COAST. WIND SPEEDS MAY
APPROACH WIND ADVISORY CRITERIA FOR AT LEAST PORTIONS OF THE DAY
ON SATURDAY WITH 925/850MB WINDS AROUND 40 TO 45KTS. ALSO WARMED
TEMPERATURES A TOUCH FURTHER GIVEN STRONG SOUTH TO SOUTHWESTERLY
WINDS JUST OFF THE SURFACE.

AS SOUTHEASTERLY WINDS INCREASE AT THE SURFACE SOUTHWESTERLY 700 TO
800MB WINDS WILL LIKELY BE DOWNSLOPING OFF OF THE MEXICAN PLATEAU TO
STRENGTHEN CAPPING IN THAT LAYER DESPITE THE INCREASE IN LOW LAYER
MOISTURE. KEPT PRECIP CHANCES MORE MEASURED DUE TO THE EXPECTATION
THIS CAPPING WILL DEVELOP AND BE STRONGER THAN GFS40/NAM12
PROJECTIONS CURRENTLY INDICATE. ANALOGS TO THIS UPPER LEVEL PATTERN
TYPICALLY PRODUCE LITTLE CONVECTION OVER MOST OF THE AREA UNTIL AN
ACTUAL FRONT ARRIVES AND MOVES INTO DEEPER MOISTURE ALONG THE COAST.
THE DRYLINE/FRONT ARRIVES BY SATURDAY AFTERNOON AND QUICKLY SHIFTS
EASTWARD OFF THE COAST. KEPT THE BEST RAIN CHANCES EAST OF HIGHWAY
77 AND ENDED THEM SHORTLY AFTER DARK. 12Z ECMWF PAINTS A FAIR AMOUNT
OF POSTFRONTAL PRECIP BUT THIS SEEMS PRETTY UNLIKELY GIVEN THE DEEP
DRY AIR SWEEPING IN ON SFC-500MB WESTERLIES BEHIND THE FRONT.
THINKING FOR NOW IS A HIGHLY CONDITIONAL WINDOW FOR THUNDERSTORMS
RIGHT ALONG THE FRONT. SHEAR/FORCING AND TO SOME EXTENT INSTABILITY
WOULD FAVOR STRONG/SEVERE STORMS IF CONVECTION OCCURS BUT CONVECTIVE
PROBABILITY IS TOO LOW FOR MUCH CONCERN AT THE MOMENT.

BEHIND THE INITIAL FRONT A REINFORCING SURGE OF HIGH
PRESSURE/PACIFIC FRONT MOVES THROUGH ON MONDAY. 12Z OPERATIONAL GFS
SEEMS TOO AGGRESSIVE WITH A SURGE OF 25 TO 35 KNOT WINDS PUSHING
INTO THE GULF ON MONDAY. ECMWF KEEPS MORE SOUTHERLY RIDGING STRONGER
OVER THE GULF OF MEXICO AND SEEMS TOO WEAK. GFS ENSEMBLE MEMBERS
SHOWED SOME DISAGREEMENT AMONGST THE FINAL SOLUTION AS WELL. THE
SYNOPTIC PICTURE SHOWS INCREASING PLAINS CONVERGENCE IN BOTH
GFS/ECMWF WHICH WOULD LIKELY LEAD TO AT LEAST SOME REINFORCING SURGE
OF HIGH PRESSURE/STRONG GULF WINDS. SO FOR THE FORECAST WENT WITH A
REINFORCING SURGE OF DRIER WINDS AT 15 TO 25 MPH BUT MORE MEASURED
THAN THE GFS SURGE OF 20 TO 30 MPH. TEMPERATURES WILL BE WARM
THROUGH THE WEEK. /68-JGG/


&&

.MARINE...
TONIGHT THROUGH THURSDAY NIGHT...BROAD HIGH PRESSURE
WILL REMAIN OVER THE NORTHWEST GULF...WITH PRESSURE FALLS
DEVELOPING OVER WEST TEXAS AND THE SOUTHERN HIGH PLAINS IN
RESPONSE TO A MID LEVEL TROUGH ADVANCING OVER THAT AREA. THE
SURFACE INTERACTION WILL STRENGTHEN SOUTHEAST WINDS ON THURSDAY
AND SEAS WILL BUILD. MARGINAL TO LOW END SMALL CRAFT ADVISORY
CONDITIONS WILL BE POSSIBLE ON THE GULF WATERS LATE THURSDAY
THROUGH THURSDAY NIGHT. SHOWERS OR LIGHT RAIN WILL ALSO BE
POSSIBLE THURSDAY AND THURSDAY NIGHT AS MOISTURE FUNNELS NORTH
ALONG A WEAK COASTAL TROUGH.

FRIDAY THROUGH MONDAY...
SOUTHEAST WINDS WILL INCREASE THROUGH THURSDAY NIGHT INTO FRIDAY.
WIND SPEEDS WILL REMAIN STRONG THROUGH SATURDAY WHEN A WEAK FRONT
PUSHES OFF THE LOWER TEXAS COAST SHIFTING WINDS TO THE WEST. WINDS
ARE EXPECTED TO BE MODERATE ON SUNDAY BEFORE A REINFORCING SHOT OF
HIGH PRESSURE INCREASES WIND SPEEDS ON MONDAY AFTERNOON AND EVENING.
SMALL CRAFT ADVISORIES ARE POSSIBLE FOR THE LAGUNA MADRE FRIDAY AND
LIKELY SATURDAY. SMALL CRAFT ADVISORIES MAY BE REQUIRED THURSDAY
NIGHT AND FRIDAY NIGHT FOR THE GULF OF MEXICO AND AGAIN ON MONDAY
EVENING.

&&

.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL  63  76  68  82 /  10  30  20  20
BROWNSVILLE          62  77  66  82 /  10  30  20  20
HARLINGEN            60  77  64  82 /  10  30  20  20
MCALLEN              60  77  64  83 /  10  20  10  10
RIO GRANDE CITY      59  76  62  82 /  10  20  10  10
SOUTH PADRE ISLAND   67  75  70  80 /  20  30  30  20

&&

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

$$

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