Areal Flood Advisory 21, NWS Brownsville, TX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
622 PM CDT WED JUN 22 2011

.DISCUSSION...SEE AVIATION SECTION FOR 00Z TAF DISCUSSION.
&&

.AVIATION...LARGE CLUSTER OF THUNDERSTORMS RAPIDLY APPROACHING
THE SOUTHEAST CORNER OF DEEP SOUTH TEXAS RIGHT NOW...AND LIKELY TO
AFFECT THE BRO AND HRL AERODROMES DURING THE VERY EARLY PORTION OF
THE TAF FORECAST. CONDITIONS WILL CALM OVERNIGHT...WITH LEFTOVER
CONVECTION DEBRIS LINGERING OVERHEAD. ANOTHER ROUND OF CONVECTION
EXPECTED...ESPECIALLY DURING THE AFTERNOON AND EVENING HOURS OF
THURSDAY.
&&

.PREV DISCUSSION... /ISSUED 144 PM CDT WED JUN 22 2011/

SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...OUTFLOW BOUNDARY
MOVING DOWN FROM THE NORTH LAST NIGHT ENDED UP CAUSING A BIT OF
RUCKUS THIS MORNING...PROVIDING A FOCUS FOR SHOWERS AND TSTORMS
ACROSS THE NORTH AND WEST SECTIONS OF DEEP SOUTH TEXAS. SOME
STORMS WERE A BIT STRONGER...WITH EMBEDDED SMALL HAIL
POSSIBLE...AND SOME RESULTED IN PERIODS OF MODERATE TO HEAVY
RAINFALL DUE TO SLOWER MOVEMENT AND DEEP MOISTURE...BUT SEVERE WAS
NOT IN THE CARDS AS OF YET...AND HEAVIER RAINS SEEMED SHY OF ANY
SERIOUS LOCAL FLOODING. WILL SEE A CONTINUATION OF ACTIVITY
THROUGH THIS EVENING AS MOISTURE FLOWS UP FROM THE SOUTH AND
REENERGIZES CONVECTION THIS AFTERNOON IN THE LOWER VALLEY.
GUIDANCE SUGGESTS THAT TROPICAL MOISTURE WILL CONTINUE TO TAKE
ADVANTAGE OF THE WEAKNESS IN THE RIDGE ALOFT AND MOVE UP ON
ANTICYCLONIC FLOW AROUND GULF HIGH PRESSURE.

LONG TERM /FRIDAY THROUGH TUESDAY/...THE MID LEVEL RIDGE IS
EXPECTED TO BEGIN TO BUILD BACK OVER THE REGION AS WE MOVE INTO
FRIDAY AND ESPECIALLY INTO THE WEEKEND. THE AREA WILL BEGIN TO DRY
BACK OUT AS A RESULT. FRIDAY WILL BRING SOME LINGERING RAIN
CHANCES...PRIMARILY FOR THE GULF WATERS AND COASTAL COUNTIES.
HOWEVER...ANY ACTIVITY WILL BE RATHER ISOLATED AND LIKELY OCCUR
DURING THE PEAK HEATING OF THE DAY. DRY CONDITIONS SHOULD RETURN
TO THE AREA BY THE WEEKEND AND INTO EARLY NEXT WEEK. THE AREA WILL
SEE A SURFACE HIGH SET UP OVER THE EASTERN GULF OF MEXICO WITH AN
AREA OF LOW PRESSURE OVER THE PLAINS STATES...WHICH WILL KEEP
SOUTHEASTERLY WINDS OVER DEEP SOUTH TEXAS THROUGH AT LEAST EARLY
NEXT WEEK.

TEMPERATURES WILL BEGIN TO WARM BACK ABOVE NORMAL AS THE MID LEVEL
RIDGE BUILDS OVER THE AREA.  HIGH TEMPERATURES ARE EXPECTED TO REACH
BY THE WEEKEND INTO THE MID 90S TOWARD THE COAST TO AROUND OR
SLIGHTLY ABOVE THE CENTURY MARK TOWARD THE UPPER VALLEY. LOW
TEMPERATURES ARE EXPECTED TO FALL INTO THE MID TO POSSIBLY ONLY
UPPER 70S EACH NIGHT THROUGH THE EXTENDED PORTION OF THE FORECAST AS
WELL. WITH WARM TEMPERATURES PERSISTING OVER THE AREA...COMBINED
WITH HIGH ENOUGH RELATIVE HUMIDITIES...THE HEAT INDICES WILL
CONTINUE TO AVERAGE FROM 100 TO 110 DEGREES IN THE PEAK OF THE
AFTERNOON EACH DAY THROUGH THE EXTENDED.

A COUPLE OF THE MODELS HINT AT THE POSSIBILITY OF ANOTHER AREA OF
LOW PRESSURE MOVING INTO THE WESTERN GULF OF MEXICO SOMETIME DURING
THE MIDDLE OF NEXT WEEK. THIS COULD BRING ANOTHER SHOT AT RAIN TO
PORTIONS OF DEEP SOUTH TEXAS IF IT PANS OUT. HOWEVER...FOR NOW HAVE
KEPT A DRY FORECAST TO WAIT FOR MORE MODEL RUNS AND TO SEE SOME
RUN TO RUN CONSISTENCY.

MARINE...TONIGHT THROUGH THURSDAY NIGHT...LIGHT SOUTHEAST WINDS
PREVAIL OFFSHORE AT BUOY 020 WITH SEAS STILL RUNNING AROUND SIX
FEET DUE TO SWELLS. WINDS WILL REMAIN MODERATE IN THE SHORT TERM
WHILE SEAS WILL SLOWLY DIMINISH. TROPICAL SHOWER AND THUNDERSTORM
ACTIVITY SHOULD CONTINUE TO SOME EXTENT THROUGH THURSDAY NIGHT
WITH SCATTERED CELLS MOVING UP FROM THE SOUTH AT A MODERATE CLIP
OF 10 TO 20 MPH. GUSTY WINDS AND HIGHER SEAS WILL EXIST NEAR ANY
STORMS. BRIEF PERIODS OF HEAVY RAINFALL MAY ALSO OCCUR IN STRONGER
STORMS.

FRIDAY THROUGH TUESDAY...A RIDGE OF HIGH PRESSURE WILL BEGIN TO
BUILD BACK OVER THE LOWER TEXAS COASTAL WATERS FOR FRIDAY AND MOVING
INTO THE WEEKEND.  WHILE THERE WILL CONTINUE TO BE SOME SMALL
CHANCES OF LINGERING SHOWERS ON FRIDAY...THIS HIGH PRESSURE WILL
ALLOW FOR DRY CONDITIONS TO RETURN FOR THE WEEKEND AND INTO EARLY
NEXT WEEK. WINDS AND SEAS ARE EXPECTED TO BE LOW TO MODERATE THROUGH
THIS TIME PERIOD AS THE PRESSURE GRADIENT WILL CONTINUE TO WEAKEN
SOMEWHAT OVER THE AREA THE NEXT FEW DAYS. WINDS EACH DAY SHOULD
AVERAGE AROUND 10 TO 15 KNOTS...WITH A FEW PERIODS OF POSSIBLE SCEC
CONDITIONS THROUGH THE MIDDLE OF NEXT WEEK. SEAS WILL GENERALLY
REMAIN IN THE MODERATE RANGE WITH AN AVERAGE OF 4 TO 6 FEET EXPECTED
FOR THE WEEKEND AND INTO EARLY NEXT WEEK.
&&

.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL  78  90  77  91 /  60  20  20  20
BROWNSVILLE          77  92  76  93 /  60  20  20  20
HARLINGEN            76  92  75  94 /  60  20  20  20
MCALLEN              78  95  77  97 /  40  20  20  20
RIO GRANDE CITY      77  97  76 100 /  20  20  10  10
SOUTH PADRE ISLAND   80  87  79  89 /  60  30  20  20
&&

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

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

AVIATION...TOMASELLI-66