000
FXUS64 KBRO 180634 AAA
AFDBRO

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
134 AM CDT SAT MAY 18 2013

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

&&

.AVIATION...THE USUAL NIGHTTIME SC DECKS ARE FORMING UP LOWERING
CEILINGS AROUND THE LOWER RGV. IR SATL IMAGERY SHOWS THAT THESE
LOW CLD DECKS WILL CONTINUE TO EXPAND FURTHER NORTH AND WEST
THROUGHOUT THE NIGHT AS THE SE LOW LEVEL FLOW CONTINUES. AFTER
SUNRISE THE INCREASING DAYTIME HEATING AND LOW LEVEL MIXING WILL
ERODE OUT THE SC DECKS ALLOWING FOR VFR CONDITIONS TO RETURN
THROUGHOUT MUCH OF THE DAYLIGHT HOURS. EXPECT THIS PATTERN TO
REPEAT ONCE AGAIN AFTER SUNSET THIS EVENING ALLOWING FOR A RETURN
OF IFR CEILINGS.

&&

.PREV DISCUSSION... /ISSUED 630 PM CDT FRI MAY 17 2013/

DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.

AVIATION...ONLY MINOR ADJUSTMENTS MADE TO THE PREVIOUS TAF
FORECAST PACKAGE. MVFR CONDITIONS CONTINUE TO BE EXPECTED TONIGHT
DUE TO THE FORMATION OF LOW CLOUDS WITH MODERATE WINDS. FULL VFR
WILL RETURN ON SATURDAY WITH INCREASING SURFACE WINDS AND RISING
CEILINGS.

PREV DISCUSSION... /ISSUED 201 PM CDT FRI MAY 17 2013/

SHORT TERM /NOW THROUGH SATURDAY NIGHT/...500 MB RIDGE ACROSS
THE REGION TODAY WILL ERODE AWAY ON SATURDAY AS A 500 MB TROUGH
MOVES EAST. THE PRESSURE GRADIENT INCREASES ON SATURDAY AS SURFACE
LOW PRESSURE DEVELOPS ACROSS THE CENTRAL PLAINS. ABOVE NORMAL
TEMPERATURES WILL CONTINUE THROUGH THE FORECAST PERIOD. HEAT
INDICES ON SATURDAY WILL RANGE FROM THE 105 TO 110 DEGREES BUT
EXPECTED TO REMAIN BELOW HEAT ADVISORY CRITERIA AT THIS TIME.
BREEZY TO WINDY CONDITIONS WILL PREVAIL THROUGH LATE THIS
AFTERNOON AND RETURN AGAIN LATE SATURDAY MORNING THROUGH THE
AFTERNOON.

LONG TERM SUNDAY THROUGH FRIDAY/...THE MID AND UPPER LEVEL PATTERN
SUNDAY THROUGH TUESDAY WILL FEATURE A BROAD MID TO UPPER LEVEL
MOVING THROUGH THE ROCKIES AND INTO THE NORTHERN AND CENTRAL
PLAINS. THE SUBTROPICAL HIGH PRESSURE RIDGE GETS TEMPORARILY
SQUASHED TO THE SOUTH AS THE TROUGH TRAVERSES THE CENTRAL PART OF
THE COUNTY. WEDNESDAY THROUGH FRIDAY TO TRANSITION BACK TO A
STRONG UPPER RIDGE OVER TEXAS AS THIS FIRST TROUGH EXITS TO THE
EAST A STRONGER TROUGH MOVES INTO PACIFIC NORTHWEST.

THE TROUGH TO REMAIN WELL NORTH OF THE CWA TO HAVE NO DIRECT AFFECT
ON THE VALLEYS SENSIBLE WEATHER. THE FORECAST TO REMAIN PERSISTENT
WITH NO SIGNIFICANT CHANCE OF RAIN IN THE LONG TERM. THERE IS SOME
SIGN OF CONVECTION FORMING ALONG THE TRAILING END OF A COLD FRONT IN
CENTRAL TEXAS NEXT TUESDAY AND/OR WEDNESDAY. HOWEVER THE PROJECTED
W-SW FLOW IN THE MID LAYERS DO NOT FAVOR ANY CONVECTION THAT FORMS
TO MOVE IN OUR DIRECTION. WE WILL CONTINUE TO MONITOR FOR ANY
CHANGES TO THIS AS WE APPROACH NEXT WEEK.

TEMPERATURES LOOK TO BE NEAR AVERAGE AS WE NEAR THE SUMMER SOLSTICE
ONLY 24 DAYS AWAY. DEEP SOUTHEAST TO SOUTH FLOW AND 850MB
TEMPERATURES RANGING BETWEEN 18 AND 22C TO KEEP TEMPERATURES RIGHT
NEAR WHERE THEY SHOULD BE THIS TIME OF YEARS.  FORECAST IS TRENDING
WITH THE SLIGHTLY WARMER EUROPEAN MOS GUIDANCE WITH VARIATION AS
CLOSER TO THE COAST AND FLUCTUATES UP AND DOWN 2 TO 4 DEGREES THROUGH
NEXT WEEK. TYPICAL BREEZY CONDITIONS TO CONTINUE THIS WEEKEND INTO
EARLY NEXT WEEK AS THE THERMAL GRADIENT INTENSIFIES BETWEEN THE
COOLER GULF WATERS AND HOT INLAND TEMPERATURES. WINDS SPEEDS TO
FLUCTUATE AS WELL THIS PERIOD AS THE STRENGTH OF THE LEE SIDE
TROUGHING VARIES WITH THE APPROACH AND PASSAGE OF THE UPPER
TROUGH.

MARINE...NOW THROUGH SATURDAY NIGHT...CURRENTLY BUOY020 REPORTS
SSE WINDS AROUND 14 KNOTS WITH GUSTS TO 18 KNOTS AND SEAS AROUND
3.6 FEET. EXERCISE CAUTION CONDITIONS EXPECTED THIS EVENING
THROUGH LATE TONIGHT OVER THE GULF WATERS AS WINDS EXPECTED TO
INCREASE BY LATER THIS EVENING. OBSERVATION PLATFORMS AROUND THE
LAGUNA MADRE INDICATE WINDS AROUND 20 KNOTS. WILL MAINTAIN THE
SMALL CRAFT ADVISORY FOR THE LAGUNA MADRE THROUGH 7 PM THIS
EVENING. ADDITIONAL SMALL CRAFT ADVISORIES MAY BE REQUIRED FOR
EITHER THE LAGUNA MADRE OR GULF WATERS THROUGH SATURDAY NIGHT.

SUNDAY THROUGH WEDNESDAY...MARINERS CAN EXPECT A MODERATE WIND
REGIME WITH MARGINAL SMALL CRAFT ADVISORY CONDITIONS AT TIMES
THROUGH THE MIDDLE OF NEXT WEEK. A LOCAL WIND PRESSURE GRADIENT
AFFECTED BY THE BROAD HIGH PRESSURE OVER THE GULF AND A
TEMPERATURE GRADIENT DEVELOPING BETWEEN THE COOLER GULF WATERS AND
THE MUCH WARMER INLAND TEMPERATURES WILL BE MAINTAIN AT A STEADY
STATE EACH DAY. AS TYPICAL CONDITIONS THIS TIME OF YEAR MARINERS
CAN EXPECT STRONGER WINDS DURING THE DAY OVER THE LAGUNA MADRE
WITH THE GULF WATERS SEEING SLIGHTLY HIGHER WINDS DURING THE
OVERNIGHT PERIOD ESPECIALLY IN THE NEAR SHORE WATERS WHERE THE
LAND AND SEA BREEZE INTERACTION IS THE STRONGEST. A STEADY STATE
SEA OF 3 TO 6 FEET ARE EXPECTED.

&&

.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL  89  76  89  75 /   0   0   0   0
BROWNSVILLE          92  76  91  75 /   0   0   0   0
HARLINGEN            96  76  91  75 /   0   0   0   0
MCALLEN              97  76  95  75 /   0   0   0   0
RIO GRANDE CITY     100  76  97  75 /   0   0   0   0
SOUTH PADRE ISLAND   82  77  83  75 /   0   0   0   0

&&

.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