Area Forecast Discussion
Issued by NWS Brownsville, TX

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FXUS64 KBRO 240002 AAA
AFDBRO

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
702 PM CDT WED JUL 23 2014

.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.

&&

.AVIATION...GENERALLY VFR CONDITIONS WILL CONTINUE FOR THE NEXT 24
HOURS AS STRONG MID LEVEL RIDGE REMAINS UPSTREAM AND BROAD SURFACE HIGH
PRESSURE DOMINATES THE GULF. A MID LEVEL DISTURBANCE WILL DRIFT
ACROSS THE WESTERN GULF OF MEXICO TONIGHT AND THURSDAY RESULTING
IN A SLIGHT CHANCE OF CONVECTION. POPS ARE NOT HIGH ENOUGH TO
MENTION IN THE TAFS AT THIS TIME. SOUTHEAST WINDS WILL DECREASE
THIS EVENING AND BECOME LIGHT OVERNIGHT. PATCHY FOG IS EXPECTED TO
REMAIN NORTH OF THE RIO GRANDE VALLEY OVERNIGHT BUT WILL MENTION A
BRIEF PERIOD OF MVFR CONDITIONS AT HRL BETWEEN 10-14Z. LIGHT TO
OCCASIONALLY MODERATE SOUTH TO SOUTHEAST WINDS EXPECTED ON
THURSDAY.

&&

.PREV DISCUSSION... /ISSUED 237 PM CDT WED JUL 23 2014/

SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...A MID LEVEL HEIGHT
CENTER IS SITUATED OVER COLORADO...AND WILL REMAIN A DOMINANT
FACTOR IN THE WEATHER PATTERN FOR THE NEXT FEW DAYS. AS A RESULT
THERE WILL BE...IN GENERAL...A PROCLIVITY TOWARD WARMER
TEMPERATURES AND LESSER RAINFALL IN THE SHORT TERM. THE FLY IN THE
OINTMENT IS A MID LEVEL WEAKNESS NOW OVER SOUTHERN
LOUISIANA...WHICH IS CHURNING UP TSTM ACTIVITY OVER THE NORTH
CENTRAL GULF. MOVEMENT OF THE FEATURE HAS BECOME A LITTLE LESS
CERTAIN LATELY...AND THE LATEST MODEL SUITE SUGGESTS THAT A WEAK
MID LEVEL TROUGH WILL SET UP OVER THE NORTH WEST GULF BETWEEN
RIDGING...HIGHER HEIGHTS...TO THE WEST AND EAST... WITH LESS
EMPHASIS ON ANY CRISPLY DEFINED LOW OR TROUGH POSSIBLY TRACKING
WEST UNDER THE H5 RIDGE...THOUGH AN H5 SHEAR AXIS AND VORT CENTER
WILL TRACK SOUTHWEST TOWARD BRO THURSDAY DURING THE DAY. THE
RESULT WILL BE A MORE DIFFUSE PRECIP CHARACTERIZATION. WILL
MAINTAIN FOR THE MOST PART THE INHERITED 20 PERCENT POPS...MAINLY
FOR THE MARINE AREAS...AND WILL CONTINUE THE TREND OF SLIGHTLY
LOWER...BY TWO OR THREE DEGREES FROM TODAY...DAYTIME HIGH TEMPS ON
THURSDAY DUE TO INCREASED HIGH CLOUD COVER. OVERNIGHT LOWS WILL
REMAIN IN THE MID 70S.

LONG TERM /FRIDAY THROUGH WEDNESDAY/...PERSISTENT UPPER LEVEL
HIGH IS EXPECTED TO BE CENTERED OVER THE TEXAS PANHANDLE ON FRIDAY
AND WILL CONTINUE TO BE THE DOMINATE WEATHER FEATURE OVER THE
RGV...NAMELY HOT AND DRY. HOWEVER...A REMNANT OF THE UPPER LEVEL
LOW MENTIONED IN THE SHORT TERM AFD WILL REMAIN IN THE VICINITY
FRIDAY AND POSSIBLY INTO SATURDAY. WHAT THIS MEANS IS THAT A FEW
VERY ISOLATED SHOWERS OR STORMS CANNOT BE RULED OUT. IF ANY
OCCUR...THEY WILL MOST LIKELY BE ASSOCIATED WITH THE SEABREEZE.
THEREFORE...I HAVE UPPED POPS A TAD AND DELINEATED THE POP
STRUCTURE ACCORDINGLY ALTHOUGH THEY DO REMAIN SILENT AND BELOW 20
PERCENT. EVEN SMALLER CHANCES FOR ISOLATED SHOWERS ON SAT BEFORE
POPS RETURN TO NEAR ZERO ON SUNDAY.

AS WE MOVE INTO THE EARLY AND MIDDLE PART OF NEXT WEEK...ANOTHER
UNUSUAL BUCKLE IN THE JET STREAM AS THE UPPER RIDGE SETS UP ACROSS
THE WESTERN US WITH A DEEP TROUGH ACROSS THE EAST. THIS WILL ALLOW
FOR A COLD FRONT TO ENTER TEXAS LIKELY REACHING AS FAR SOUTH AS
CENTRAL TEXAS. THIS WILL INCREASE RAIN CHANCES OVER MUCH OF TEXAS
BUT NO RELIEF EXPECTED FOR DEEP SOUTH TEXAS AT LEAST THROUGH
WEDNESDAY. WHILE THE FRONT IS NOT EXPECTED TO REACH THE
VALLEY...AT LEAST AT THIS TIME...THE NORTHERLY FLOW ALOFT MAY
DRIVE FRONTAL INDUCED CONVECTION INTO THE REGION BY THURSDAY OR
FRIDAY WHICH IS STILL OUTSIDE OF THIS FORECAST PERIOD. UNTIL
THEN...DRY.

TEMPERATURES WERE GENERALLY KEPT IN TACT WITH ONLY MINOR TWEAKS.
TWEAKED LOW TEMPS DOWNWARD A COUPLE OF DEGREES TO ACCOMMODATE
CURRENT TRENDS THERE. HEAT INDICIES TO GENERALLY RANGE FROM 103 TO
110 EACH DAY ACROSS INLAND AREAS.

MARINE...TONIGHT THROUGH THURSDAY NIGHT...WINDS AND SEAS WILL REMAIN VERY
REASONABLE IN THE SHORT TERM. BROAD HIGH PRESSURE WILL RULE AT THE
SURFACE ON THE GULF...WITH LIGHT TO MODERATE SOUTH SOUTHEAST WINDS
AND LOW SEAS OF ONE TO THREE OR TWO TO FOUR FEET. SHOWERS AND TSTMS
ARE BEING GENERATED OVER THE NORTHWEST GULF BY A MID LEVEL WEAKNESS
ALOFT OVER THAT AREA...AND THE CONVECTION WILL TEND TO DRIFT SOUTH
INTO THE LWR TX COASTAL WATERS WITH THE NORTH TO NORTHWEST STEERING
FLOW ABOVE THE SURFACE. THE UPPER TROUGH WILL FILL AND WEAKEN OVER
TIME...BUT THROUGH THE SHORT TERM ISOLATED SHOWERS AND THUNDERSTORMS
MAY DRIFT INTO THE GULF MARINE ZONES.

FRIDAY THROUGH MONDAY...WITH HIGH PRESSURE DOMINATING THROUGH THE
WEEKEND INTO EARLY NEXT WEEK...GENERALLY FAVORABLE MARINE
CONDITIONS ARE ANTICIPATED. BIGGEST CONCERN WILL BE AFTERNOON
WINDS OF AROUND 15 KNOTS OR SO...BUT SHOULD STAY BELOW SMALL CRAFT
EXERCISE CAUTION CRITERIA. COULD BE A FEW ISOLATED SHOWERS ACROSS
THE GULF WATERS ON FRIDAY IN ASSOCIATION WITH REMNANTS OF A WEAK
UPPER LEVEL LOW. SEAS EXPECTED TO REMAIN AT OR BELOW THREE FEET
THROUGH THE PERIOD.

&&

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

$$

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

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