Area Forecast Discussion
Issued by NWS Brownsville, TX

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FXUS64 KBRO 301217 AAA
AFDBRO

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
717 AM CDT WED JUL 30 2014

.DISCUSSION...UPDATED FOR LATEST AVIATION AND FIRE WEATHER DISCUSSION
BELOW.

&&

.AVIATION...JUST A FEW TWEAKS TO THE PRIOR FORECAST. PATCHY MVFR
CEILING HAS FORMED EARLY THIS MORNING BUT IS FAVORING THE NORTHERN
RANCHLANDS. WITH SOME MIXING WITH SURFACE WINDS ALREADY AROUND 5-7
KNOTS AM NOT EXPECTING MVFR TO FORM UP AGAIN THIS MORNING IN KMFE
AS IT HAS THE PAST TWO MORNINGS. THE OTHER TWEAK IS TO RAISE
WINDS...AND GUSTS...EARLIER IN THE PERIOD /AROUND 15Z/ BASED ON
23-24 KT WIND AROUND 2400 FEET WHICH SHOULD MIX DOWN TO SOME
DEGREE.

THEREAFTER...NO CHANGE AS ANY CUMULUS LIFT WELL INTO THE VFR RANGE
AND THIN OUT CONSIDERABLY...FEW AT BEST BY 18-21Z. SKIES GO CLEAR
BY SUNSET AND WINDS DROP BACK SOON AFTER.
52/BSG

&&

.FIRE WEATHER...WILL SOON HOIST A FIRE DANGER STATEMENT BASED ON
EASILY ACHIEVING LOW HUMIDITY INLAND COMBINED WITH AFOREMENTIONED
20 FOOT WINDS WHICH SHOULD TOUCH INTO THE 15-20 MPH RANGE BETWEEN
2 AND 6 PM IN HIDALGO AND STARR COUNTY. WILL ADD BROOKS AND JIM
HOGG EVEN THOUGH WINDS WILL BE RIGHT ON THE MARGIN...BUT DROUGHT
LEVELS IN THE SOUTHERN HALF OF EACH COUNTY SNEAKING TOWARD THE MORE WORRISOME
SEVERE DROUGHT THAT COVERS MOST OF STARR AND WESTERN/NORTHERN
HIDALGO COUNTY. A SMALL BUT POTENT WILDFIRE NEAR ALAMO TUESDAY
AFTERNOON ADDS MORE CONFIDENCE IN BRINGING OUT THE THREAT AS WELL.
52/BSG

&&

.PREV DISCUSSION... /ISSUED 330 AM CDT WED JUL 30 2014/

SHORT TERM /NOW THROUGH THURSDAY/...BIG BUBBLE...HEAT ON THE
DOUBLE! ANOTHER WAY OF SAYING BROKEN RECORD OF SENSIBLE WEATHER
RIGHT INTO THURSDAY. THE PERFECT BEACH WEEK CONTINUES FOR THE
VALLEY.

ATMOSPHERICALLY...500 MB RIDGE REMAINS PARKED ON A WEST NORTHWEST TO
EAST-SOUTHEAST AXIS FROM SOUTHERN NEW MEXICO THROUGH THE RGV AND
WESTERN GULF TODAY.  THE RIDGE BEGINS "TIPPING" TOWARD A MORE
NORTHWEST-SOUTHEAST AXIS ON THURSDAY...THE BEGINNING OF A SLIGHT
PATTERN CHANGE THAT WILL BRING SOME INCLEMENT WEATHER AS WE HEAD
INTO THE WEEKEND (SEE LONG TERM DISCUSSION FOR THE DETAILS). THAT
"TIPPING" WILL HAVE NO NOTABLE IMPACT ON THE VALLEY WEATHER HOWEVER.

IN SUMMARY: WHAT YOU SEE IS WHAT YOU GET. ABOUT THE ONLY CHANGE
FOLKS WILL SEE BETWEEN TODAY AND THURSDAY...IF THEY`RE PAYING
ATTENTION...WILL BE A BIT MORE COVERAGE OF CLOUDS FROM LATE MORNING
TO EARLY AFTERNOON THURSDAY AWAY FROM THE COAST. STILL NOT ENOUGH TO
MAKE A DENT IN HIGH TEMPERATURES WHICH WILL REMAIN AMONG THE HOTTEST
THIS SUMMER...WITH CENTURY MARK READINGS ALONG AND WEST OF HIGHWAY
77...95 TO 99 ELSEWHERE EXCEPT LOWER 90S AT THE BEACH.  WINDS WILL
INCREASE TO A FRESH BREEZE BY MID MORNING EACH DAY AND GET A SECOND
BOOST FROM SEA BREEZE ENHANCEMENT BY 2-4 PM OR SO EACH DAY...WITH
GUSTS A SHADE HIGHER BOTH DAYS THAN THEY WERE ON TUESDAY.

AS FOR HEAT INDEX...ONCE AGAIN THE MIXING OF DRY AIR ABOVE THE
SURFACE WILL KEEP VALUES IN CHECK WITH MOST AREAS SEEING HEAT INDEX
VALUES ABOUT THE SAME AS THE ACTUAL TEMPERATURE...WITH ONLY
EXCEPTION NEAR THE COAST WHERE THE COMBINATION WILL MAKE IT FEEL
CLOSER TO 100-105.

LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...RAIN CHANCES WILL
INCREASE TO NON NEGLIGIBLE LATE THIS WEEK AND INTO THIS WEEKEND TO
EARLY NEXT WEEK THANKS TO THE PROXIMITY OF A DISSIPATING OLD FRONTAL
BOUNDARY HANGING OVER THE AREA. IT WILL BE TUESDAY OR WEDNESDAY OF
NEXT WEEK BEFORE A MORE SETTLED PATTERN RETURNS...BUT EVEN SO...SOME
MARINE SHOWER ACTIVITY MAY CONTINUE OVER THE GULF.

A WEAK FRONTAL BOUNDARY WILL PERSIST ACROSS SOUTH CENTRAL TEXAS
THURSDAY. THE FRONT WILL DRIFT A BIT FARTHER SOUTH ON FRIDAY AND
WILL "HANG UP" ACROSS THE NORTHERN PORTION OF THE CWA ON SATURDAY.
MOISTURE POOLING NORTH OF THE BOUNDARY AND INSTABILITY ALONG IT WILL
INCREASE RAIN CHANCES LATE FRIDAY THROUGH AROUND MONDAY...BEING
MOSTLY DIURNALLY DRIVEN. MORE SIGNIFICANT CONVECTION COULD DEVELOP
AT THE TAIL END OF THE FRONT OVER THE RIO GRANDE PLAINS AND THE
MEXICAN PLATEAU SATURDAY AND SUNDAY NIGHTS...WITH THE POSSIBILITY OF
SOME ACTIVITY DRIFTING EAST INTO DEEP SOUTH TEXAS AND THE RIO GRANDE
VALLEY. OVERALL HOWEVER...DAYTIME SHOWER AND TSTM ACTIVITY LOOK TO
BE MAINLY ISOLATED TO SCT RIGHT NOW. IN ADDITION TO THE STALLED
FRONT...THE UPSTREAM MID LEVEL RIDGE WILL REMAIN AT BAY OVER THE
SOUTHERN ROCKIES...WITH EVEN SOME SOUTHWEST MONSOONAL INSTABILITY
GETTING INTO THE ACT WITH ENERGY MOVING FROM WEST TO EAST OVER
NORTHERN MEXICO...SUPPORTING THE SATURDAY AND SUNDAY NIGHT
CONVECTION MENTIONED EARLIER.

THERE WILL BE A LITTLE MODERATION IN DAYTIME TEMPERATURES SUNDAY AND
MONDAY DUE TO INCREASED CLOUD COVER AND THE RETREAT OF THE MID LEVEL
RIDGE...LOWERING COLUMN HEIGHTS...BUT DON`T HOLD YOUR BREATH FOR
ANYTHING MUCH BELOW NORMAL. THE RIDGE WILL TRY TO BUILD BACK OVER
THE AREA EARLY NEXT WEEK WITH SOME MID LEVEL DRYING. HOWEVER...THE
MODELS SEEM TO BE IN A GENERAL AGREEMENT IN PLACING THE RGV AND ALL
OF COASTAL TEXAS IN A WEAK TROUGH OR WEAKNESS BETWEEN THE DESERT SW
RIDGE AND THE BERMUDA HIGH IN THE NORTHWEST CARIBBEAN AND EAST GULF.
ENOUGH MOISTURE COULD SUPPORT A SEA BREEZE ON MONDAY AND MAYBE
TUESDAY...BUT LESS LIKELY AFTER THAT AS THE ENVIRONMENT BECOMES
DRIER.

THE INHERITED FORECAST WAS KEPT MAINLY INTACT. AS MENTIONED...THE
HEAT WILL CONTINUE THURSDAY AND FRIDAY...WITH MID 90S COAST TO 100
OR MORE OUT WEST...BUT MAYBE LESS HOT SATURDAY THROUGH MONDAY BY A
FEW DEGREES WITH A MENTION OF SHOWERS AND THUNDERSTORMS FRIDAY NIGHT
THROUGH MONDAY. LOW TEMPS WILL CONTINUE TO BE IN THE 70S TO NEAR 80.

MARINE...
TODAY THROUGH THURSDAY...DIURNAL TRENDS THAT HAVE RULED THE PAST
FEW DAYS WILL DOMINATE AGAIN TODAY AND THURSDAY. ON THE GULF...
MODERATE WINDS OVERNIGHT AND LIGHT WINDS DURING THE DAY...WITH THE
OPPOSITE EFFECT ON THE LAGUNA MADRE. SEAS WILL REMAIN BELOW 3 FEET
AND SURF WAVES 1 TO 2 FEET IN SETS...FLAT AT OTHER TIMES...WITH
VERY LOW OFFSHORE WAVE PERIOD (SWELL) KEEPING THINGS WELL IN HAND.

THURSDAY NIGHT THROUGH SUNDAY...MID LEVEL RIDGING WILL NOT BE QUITE
AS FORMIDABLE THURSDAY NIGHT...RETREATING WEST A BIT...BUT STILL
HOLDING A GRIP OVER WEST TEXAS. A LARGE SCALE TROUGH WILL EXTEND
SOUTH OVER THE LWR MISSISSIPPI VALLEY WHILE A FLAT PRESSURE GRADIENT
REMAINS OVER THE GULF. AN OLD FRONTAL BOUNDARY MAY STILL BE IN THE
VICINITY JUST TO THE NORTH OF THE CWA AND COULD BE THE FOCUS FOR
CONVECTION AS IT SAGS SOUTH. THE CURRENT MODEL SUITE SUGGESTS THAT
THE BOUNDARY WILL RETAIN SOME WEAK DELINEATION THROUGH THE WEEKEND
AND MAY PRODUCE CONVECTION OVER THE WATER ON BOTH SUNDAY AND MONDAY
AS WELL AS A SLIGHT DISRUPTION IN THE TYPICAL SOUTHEAST WIND...IN
FAVOR OF A WEAK EAST WIND. WAVE HEIGHTS WILL SEE LIMITED CHANGE
HOWEVER...REMAINING A MODERATE 2 TO 4 FEET THROUGH THE LONG TERM.
THE CURRENT 20 TO 30 PERCENT CHANCE OF POPS FOR MUCH OF THE WEEKEND
LOOKS GOOD AND WILL LIKELY KEEP THE NUMBERS IN ABOUT THAT AREA WITH
OUT TOO MUCH TWEAKING.

CLIMATE...THE HOT CLOSEOUT OF JULY GENERALLY COUNTERBALANCES THE
SOMEWHAT LOWER TEMPERATURES EXPERIENCED DURING THE FIRST HALF OF THE
MONTH. WHEN ALL IS SAID AND DONE...THE MONTH WILL SQUEAK INTO THE
ABOVE AVERAGE CAMP BUT JUST BARELY...BASED ON THE 1981-2010
AVERAGES. PLENTY OF CENTURY MARK DAYS...NOTHING AS CRAZY AS 2009
WHEN MCALLEN/MILLER HAD 30 OUT OF 31 DAYS HIT 100 WITH A SEARING
AVERAGE OF 104 FOR THE MONTH OVERALL...HARLINGEN HAD 12 CENTURY MARK
DAYS...AND BROWNSVILLE TWO.

STILL...NOT TOO SHABBY WITH MCALLEN ENDING AT 17 WHEN ALL IS SAID
AND DONE INCLUDING 13 STRAIGHT TO END THE MONTH...AND HARLINGEN
ENDING POTENTIALLY WITH 8 OF THE LAST 10 DAYS FINISHING AT 100 OR
HIGHER.

&&

.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL  99  78  99  80 /   0   0   0  10
BROWNSVILLE          96  77  96  79 /   0   0   0  10
HARLINGEN           101  74 101  78 /   0   0   0  10
MCALLEN             102  76 102  79 /   0   0   0  10
RIO GRANDE CITY     103  77 103  79 /   0   0   0  10
SOUTH PADRE ISLAND   92  80  92  81 /   0   0   0  10

&&

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

$$

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