Area Forecast Discussion
Issued by NWS Brownsville, TX

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FXUS64 KBRO 250233 AAB
AFDBRO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
933 PM CDT FRI MAY 24 2013

.DISCUSSION...REMOVED POPS FOR TONIGHT ACROSS INLAND AREAS AS
SHOWERS AND THUNDERSTORMS HAVE DISSIPATED. SLIGHT CHANCE POPS WERE
INSERTED OR MAINTAINED ACROSS ALL OF THE OFFSHORE WATERS AS
STREAMER SHOWERS WERE ALREADY DEVELOPING AND WILL LIKELY PERSIST
THROUGH THE NIGHT.

&&

.PREV DISCUSSION... /ISSUED 800 PM CDT FRI MAY 24 2013/

DISCUSSION...UPDATED FOR POPS...QPF AND SKY COVER FOR THIS
EVENING. INCREASED POPS FOR THIS EVENING ACROSS CENTRAL AND
EASTERN ZONES. ALTHOUGH SHOWERS AND THUNDERSTORMS ARE
DIMINISHING...ISOLATED TO SCATTERED ACTIVITY WILL LIKELY LINGER
UNTIL 10 PM OR SO.

AVIATION...
A LARGE AREA OF SHOWERS AND THUNDERSTORMS HAS MOVED INTO THE
CENTRAL AREAS OF THE RIO GRANDE VALLEY AND DEEP SOUTH TEXAS. THIS
ACTIVITY WILL LIKELY IMPACT KMFE FOR THE NEXT COUPLE OF HOURS OR SO
BEFORE DISSIPATING. THERE IS A SLIGHT CHANCE THAT A FEW SHOWERS
MAY IMPACT KHRL AROUND 02Z AND IF LESS LIKELY TO IMPACT KBRO.
THEREFORE NO SHRA WAS INTRODUCED INTO THEIR TAFS AT THIS TIME.
OTHERWISE...CEILINGS WILL QUICKLY RETURN AT ALL THREE SITES AFTER
SUNSET AND SHOULD FALL TO AROUND 1500 FEET A FEW HOURS AFTER
MIDNIGHT. CEILINGS MAY BE SLOW TO LIFT SAT MORNING BUT VFR
CONDITIONS ARE LIKELY BY AFTERNOON.

PREV DISCUSSION... /ISSUED 234 PM CDT FRI MAY 24 2013/

SHORT TERM /NOW THROUGH SATURDAY NIGHT/...LINE OF THUNDERSTORMS
RUNNING FROM THE TEXAS HILL COUNTRY SOUTHWARD TO LAREDO AND
CONTINUING INTO MEXICO MOVING EAST...BEING PUSHED BY DUAL MCVS
CENTERED IN THE HILL COUNTRY AND NEAR KCOT. WHILE GOOD LOWER LEVEL
MOISTURE IS AVAILABLE /PW AT KBRO WAS 1.79 INCHES THIS MORNING/
AND GOOD DAYTIME HEATING GOING FOR MOST OF THE VALLEY...LACK OF
SIGNIFICANT SHEARING WILL PRECLUDE THESE FORM GETTING TOO HEFTY
THIS AFTERNOON. INCREASED POP CHANCES FOR THE REST OF THE DAY
TODAY AND TONIGHT...ESPECIALLY FOR AREAS NORTH OF THE VALLEY. MAIN
THREAT FROM ANY THUNDERSTORMS WOULD BE GUSTY WINDS NEARER TO THE
MCV AND HEAVY DOWNPOURS. WILL KEEP AN EYE OF END OF LINE CELL FOR
POSSIBLE LOCALIZED SHEAR ENHANCEMENTS. THE MCS WILL MOVE TO THE
EAST TONIGHT AS MOST OF THE MIDLEVEL IMPULSE DEPARTS TO THE NE.
MODELS ARE NOW MORE IN LINE WITH PART OF THE IMPULSE WRAPPING BACK
AROUND THE RIDGE AND REMAINING OVER TEXAS TOMORROW AND TOMORROW
NIGHT...PUSHING THE RIDGE FURTHER TO THE WEST. THIS WILL CONTINUE
TO PROVIDE SOME INSTABILITY TO THE REGION...BUT LESSER AMOUNTS
THAN TODAY. HAVE GONE AHEAD AND ADDED A SMALL RAIN CHANCE OUT WEST
AGAIN TOMORROW.MORE CLOUD COVER AGAIN TOMORROW WILL HOLD BACK
TEMPERATURES A COUPLE DEGREES...HOVERING A COUPLE DEGREES EITHER
SIDE OF 90...WITH LOW 80S ALONG THE COAST.

LONG TERM...SUNDAY THROUGH FRIDAY...THE MID LEVEL RIDGING WILL BE
ERODED AWAY SOME IN THE LONGER TERM PERIOD AS A PRETTY STRONG WEST
COAST TROUGH DIGS EAST AND CLOSES OFF OVER THE DESERT SW. THE SW
FLOW ALOFT INDUCED BY THIS TROUGH/CLOSED LOW WILL TEND TO DRY OUT
AND STABILIZE THE ATMS LATER NEXT WEEK UNTIL THE TROUGH AXIS
MOVES CLOSER INTO THE SOUTH CENTRAL PLAINS STATES TOWARDS NEXT THURS
AND FRI. THE ECMWF REFLECTS A SHARPER 500 MB CLOSED LOW DEVELOPING
OVER THE DESERT SW ON AND AFTER WED VERSUS THE GFS. THIS IS THE
BIGGEST DISAGREEMENT AMONG THE LONGER RANGE GUIDANCE.

DUE TO THE INFLUENCE OF THE SUBSIDENT RIDGING AND DRYING OF THE
ATMS THE 1000-500 MB THICKNESSES WILL REMAIN ELEVATED THROUGH NEXT
WEEK RESULTING IN TEMPS ABOVE CLIMO. THE ECMWF TEMPS HAVE A LITTLE
MORE WARMER BIAS VERSUS THE MEX MOS. RUN TO RUN CONSISTENCY WITH
THE MEX MOS IS PRETTY DECENT THROUGH NEXT WED WITH A LITTLE MORE
UNCERTAINTY SHOWING UP FOR THURS AND FRI.

WILL WARM UP HIGH TEMPS A BIT THROUGHOUT THE LONGER RANGE PERIOD
MORE IN LINE WITH THE ECMWF NUMBERS. MIN TEMPS LOOK PRETTY GOOD
WITH NO MAJOR CHANGES NEEDED HERE. WILL INCREASE THE POPS A BIT IN
THE LONGER RANGE BUT WILL STILL LEAVE AS SILENT 10% AT THIS TIME
AS AM NOT TOO CONFIDENT OF ANY MEAURABLE RAINFALL DEVELOPING LATER
NEXT WEEK DUE TO THE INFLUENCE OF THE MID LEVEL RIDGING.

MARINE...TONIGHT THROUGH SATURDAY NIGHT...LITTLE DISRUPTION OF THE
SFC PATTERN EXPECTED THROUGH THE NEXT 36 HOURS. HIGH PRESSURE RIDGE
ACROSS THE GULF CONTINUES THE SE FLOW FOR SOUTH TEXAS. SOME
INCREASED BREEZES MAY PICK UP LATER TOMORROW AS LOW PRESSURE TRIES
TO BUILD ACROSS WEST KANSAS. GENERALLY NEAR 15 KNOTS TONIGHT
BECOMING 15 TO 20 KNOTS TOMORROW. NO ADVISORIES ARE EXPECTED...BUT
SMALL CRAFT SHOULD EXERCISE SOME CAUTION WITH THE BREEZES TOMORROW.
WAVE HEIGHTS REMAIN RIGHT AROUND 4 FEET FOR THE GULF.

SUNDAY THROUGH TUESDAY...THE PGF WILL INCREASE IN THE LONGER
RANGE PERIOD DUE TO THE DEVELOPMENT OF A PRETTY STRONG SURFACE LOW
PRESSURE SYSTEM IN THE MIDWEST. THIS SYSTEM WILL LIKELY PUSH THE
WINDS AND SEAS IN THE LATER CWF PERIODS UP CLOSE TO SCA LEVELS FOR
BOTH THE BAY AND GULF WATERS.

&&

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

$$

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