Area Forecast Discussion
Issued by NWS Brownsville, TX

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000
FXUS64 KBRO 110701 AAA
AFDBRO

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
201 AM CDT FRI APR 11 2014

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

&&

.AVIATION...CURRENTLY HIGH LEVEL CIRRUS IS THE ONLY CLD DECKS
MOVING OVER DEEP SOUTH TX. THE 00Z BRO SOUNDING SHOWS A VERY DRY
ATMS IN PLACE OVER THE AREA AS SOUTHEASTERLY LOW LEVEL FLOW
RETURNS TO THE AREA. EXPECT SOME SCT SC DECKS TO FORM UP LATER
THIS AFTERNOON AS THE DAYTIME HEATING INTERACTS WITH THE RETURNING
LOW LEVEL MOISTURE MOVING IN OFF OF THE GULF OF MEX. FORECAST
SOUNDINGS FROM BOTH THE NAM AND GFS MODELS INDICATE SOME BETTER
POTENTIAL FOR LOW CLD DECKS TO FORM UP VERY LATE IN THE CURRENT
TAF PERIOD AND HAVE INCLUDED A MENTION OF THIS IN THE LAST FEW
HOURS OF THE FORECAST PERIOD. GENERALLY EXPECT VFR CONDITIONS TO
PREVAIL FOR MOST OF THE CURRENT TAF PACKAGE.

&&

.PREV DISCUSSION... /ISSUED 632 PM CDT THU APR 10 2014/

DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.

AVIATION...SKIES WILL REMAIN MOSTLY CLEAR OVERNIGHT...WITH ONLY
SOME PASSING CI. BREEZY CONDITIONS WILL SLACKEN SLIGHTLY
OVERNIGHT...BUT WILL REMAIN ELEVATED AROUND 15 KNOTS WITH GUSTS
AROUND 20 KNOTS. WINDS WILL INCREASE AGAIN TOMORROW
MORNING...REACHING THE LOW 20S SUSTAINED FOR KBRO AND KHRL AND
GUSTING INTO THE LOW 30S. LOW CLOUDS WILL BE MINIMAL...BUT CI
SHIELD MAY INCREASE FURTHER DURING THE AFTERNOON.

PREV DISCUSSION... /ISSUED 212 PM CDT THU APR 10 2014/

SHORT TERM /NOW THROUGH FRIDAY NIGHT/...
WEAK 500MB RIDGE ACROSS NORTHERN MEXICO AND WEST TEXAS TONIGHT WILL
SHIFT EASTWARD FRIDAY REINFORCING THE SUBSIDENCE ACROSS THE RIO
GRANDE VALLEY THROUGH FRIDAY NIGHT. NOCTURNAL LOW LEVEL JET WILL
DEVELOP TONIGHT ALLOWING SOME LOW LEVEL MOISTURE TO INCREASE TONIGHT
INTO FRIDAY. BREEZY TO WINDY CONDITIONS WILL RETURN FRIDAY AS
DIURNAL HEATING ALLOWS STRONGER WINDS ALOFT TO MIX DOWN. BELIEVE
MIXING TOO STRONG TONIGHT FOR FOG BUT COULD SEE SOME CLOUDS DEVELOP
LATE TONIGHT. MAY SEE SOME FOG FRI NIGHT ALONG THE COASTAL SECTIONS
AS THE NOCTURNAL LOW LEVEL JET DOES NOT LOOKS AS STRONG TOMORROW
NIGHT AS TONIGHT. BOTH THE NAM AND GFS LOOK FAIRLY CONSISTENT ON
TEMPERATURES SO WILL GO WITH A BLEND OF ADJUSTED MET/MAV MOS
GUIDANCE FOR TEMPS TONIGHT THROUGH FRI NIGHT. /61/

LONG TERM /SATURDAY THROUGH THURSDAY/...
FORECAST CONFIDENCE IS ABOVE AVERAGE HEADING INTO THE LONG TERM
PORTION OF THE FORECAST THANKS (AT LEAST IN PART) TO GOOD MODEL
CONSISTENCY.  THE PRIMARY TARGET OF OPPORTUNITY APPEARS TO BE
IMPACTS ASSOCIATED WITH THE PASSAGE OF A COLD FRONT MONDAY.

A SPLIT UPPER-LEVEL FLOW IS EXPECTED TO BE SEEN AT THE START OF THE
LONG TERM PORTION OF THE FORECAST.  IN THE SOUTHERN STREAM...AN
UPPER LOW (OVER SOCAL SATURDAY MORNING) IS EXPECTED TO MOVE ACROSS
THE DESERT SOUTHWEST THIS WEEKEND.  MEANWHILE...ANOTHER SHORTWAVE
TROUGH (IN THE NORTHERN STREAM) SHOULD DIG INTO THE ROCKIES
SUNDAY...SOMEWHAT PHASING WITH THE SOUTHERN STREAM SYSTEM OVER THE
SOUTHERN PLAINS.  THESE TWO SYSTEMS SHOULD AID IN BRINGING A COLD
FRONT SOUTH INTO THE LONE STAR STATE.

IT STILL LOOKS LIKE THE FRONT SHOULD BE KNOCKING ON THE DOOR TO OUR
NORTHERN TIER OF COUNTIES AROUND SUNRISE MONDAY.  GIVEN THE
ANTICIPATED AMPLITUDE OF THE UPPER SYSTEM...THERE SHOULD BE ENOUGH
SUPPORT TO PUSH THE FRONT INTO NORTHERN MEXICO AROUND NOON (+/- 1-2
HOURS).

AN EAST TO SOUTHEAST FLOW NEAR THE SURFACE SHOULD CONTINUE TO
INCREASE LOW-LEVEL MOISTURE ACROSS THE REGION AHEAD OF THE NEXT
STORM SYSTEM.  PRECIPITABLE WATER VALUES ARE FORECAST TO APPROACH
1.5 INCHES BY SUNDAY NIGHT...WHICH IS A LITTLE MORE THAN THE 75TH
PERCENTILE CLIMATOLOGICALLY.  EVEN WITH THIS...AND INCREASING
UPPER-LEVEL SUPPORT...I EXPECT A LOW COVERAGE OF CONVECTIVE ACTIVITY
(IF ANY AT ALL) PRIOR TO THE ARRIVAL OF THE FRONT.  THE CAPPING
INVERSION JUST APPEARS TO REMAIN TOO STRONG IN FORECAST SOUNDINGS
THIS AFTERNOON.

THE INVERSION MAY WEAKEN SOMEWHAT WITH THE APPROACH OF THE FRONT...
ALLOWING FOR A LITTLE BIT MORE IN THE WAY OF CONVECTIVE DEVELOPMENT
BY MONDAY MORNING.  GIVEN FORECAST SURFACE-BASED PARCEL BUOYANCY
VALUES...SOME THUNDERSTORMS MAY ALSO BE SEEN.  WITH SLIGHTLY DEEPER
LOW-LEVEL MOISTURE EXPECTED TO POOL NEAR THE FRONT...I EXPECT THE
GREATEST CONVECTIVE COVERAGE TO BE SEEN ALONG AND AHEAD OF THE
SOUTHWARD-MOVING BOUNDARY.  CONVECTIVE COVERAGE MAY BE FURTHER
LIMITED BY A WESTERLY FLOW IN THE MIDDLE AND UPPER ATMOSPHERE...
WHICH WILL BRING A MORE SUBSIDENT FLOW OFF THE MOUNTAINS IN NORTHERN
MEXICO.

LONG STORY SHORT... IT LOOKS LIKE A LINE OF SHOWERS AND STORMS MAY
BE SEEN AS THE FRONT MOVES THROUGH THE REGION.  BASED ON WHAT I`M
SEEING...THE ONGOING PRECIPITATION PROBABILITIES APPEAR TO BE IN THE
BALLPARK.

WINDS SHOULD BECOME NORTHERLY IN WAKE OF THE FRONT AFTER THE PASSAGE
OF THE STORM SYSTEM.  TEMPERATURES TUESDAY WILL BE NOTICEABLY COOLER
BEHIND THE FRONT.  LATEST GUIDANCE BLEND INDICATED FORECAST HIGHS
TUESDAY WHICH ARE ABOUT 10 DEGREES COOLER THAN CURRENTLY FORECAST.
WHILE NOTHING (ESPECIALLY IN METEOROLOGY) IS OUT OF THE QUESTION...
THOSE VALUES MAY BE A BIT UNREALISTIC FOR MID-APRIL GIVEN 850MB
TEMPERATURES.  THAT SAID...I HAVE COOLED TEMPERATURES A BIT FOR
TUESDAY...BUT NOT QUITE AS MUCH AS SUGGESTED BY THE GUIDANCE.  NEVER
FEAR THOUGH...SHORTWAVE RIDGING BETWEEN STORM SYSTEMS SHOULD ALLOW
NEAR NORMAL TEMPERATURES (MIDDLE 80S FOR HIGHS/MIDDLE 60S FOR LOWS)
TO BE SEEN BY THE MIDDLE OF NEXT WEEK.

THANKS TO WFO CORPUS CHRISTI FOR COLLABORATION THIS AFTERNOON.  /53/

MARINE...

TONIGHT THROUGH FRIDAY NIGHT...
SEAS WERE NEAR 4 FEET WITH SOUTHEAST WINDS NEAR 14 KNOTS AT BUOY020
THIS AFTERNOON. MODERATE TO STRONG SOUTHEAST WINDS WILL PREVAIL
ACROSS THE COASTAL WATERS TONIGHT INTO FRIDAY AS THE PRESSURE
GRADIENT REMAINS STRONG ACROSS THE WESTERN GULF OF MEXICO. WILL WORD
SCEC FOR THE OFFSHORE WATERS TONIGHT AND SMALL CRAFT ADVISORIES WILL
LIKELY BE NEEDED FOR THE LAGUNA MADRE FRIDAY. THE PRESSURE GRADIENT
SHOULD WEAKEN SLIGHTLY FRI NIGHT AND MODERATE SOUTHEAST WINDS SHOULD
PREVAIL ACROSS THE COASTAL WATERS AS A RESULT. /61/

SATURDAY THROUGH TUESDAY...
A STRENGTHENING PRESSURE GRADIENT...AHEAD OF AN APPROACHING STORM
SYSTEM...SHOULD RESULT IN INCREASED WIND SPEEDS OVER THE MARINE AREA
THIS WEEKEND.  THIS MAY REQUIRE SMALL CRAFT TO EXERCISE CAUTION OR
THE ISSUANCE OF SMALL CRAFT ADVISORIES BY SUNDAY.  WINDS MAY ABATE A
BIT MONDAY AS A COLD FRONT MOVES ACROSS THE MARINE AREA...BEFORE
BECOMING NORTHERLY BEHIND THE FRONT AND INCREASING IN SPEED.
ADDITIONAL SMALL CRAFT ADVISORIES MAY BE REQUIRED THROUGH EARLY NEXT
WEEK DUE TO STRONGER WINDS AND HIGHER SEAS. /53/

&&

.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL  81  70  80  72 /   0   0  10  10
BROWNSVILLE          84  68  83  73 /   0   0  10  10
HARLINGEN            86  70  84  72 /   0   0  10  10
MCALLEN              89  70  87  72 /   0   0  10  10
RIO GRANDE CITY      91  67  89  72 /   0   0  10  10
SOUTH PADRE ISLAND   77  69  77  72 /   0   0  10  20

&&

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

$$

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

SHORT TERM...60
LONG TERM...68





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