000
FXUS64 KBRO 031609 AAC
AFDBRO

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
1009 AM CST MON MAR 3 2014

.DISCUSSION...BRO RADAR AND SURFACE OBSERVATIONS INDICATE THAT
THUNDERSTORMS ACROSS PORTIONS OF THE WESTERN AND NORTHERN
RANCHLANDS THIS MORNING HAVE DIMINISHED. MUCAPE VALUES HAVE
DECREASED SO ADDITIONAL THUNDERSTORM ACTIVITY IS NOT ANTICIPATED
FOR THE REST OF TODAY. HAVE REMOVE THUNDERSTORM WORDING FROM THE
GRIDS. ALSO...MADE A FEW MINOR ADJUSTMENTS TO THE WINDS AND
DEWPOINT GRIDS BASED ON CURRENT OBSERVATIONS AND TRENDS. TEXT
PRODUCTS HAVE BEEN SENT.

&&

MARINE...MARINE OBSERVATIONS PLATFORMS INDICATE THAT WINDS AND GUSTS
HAVE DIMINISHED TO BELOW GALE WARNING CRITERIA. THEREFORE...THE
GALE WARNING FOR THE MARINE AREA HAS BEEN ALLOWED TO EXPIRE. A
SMALL CRAFT ADVISORY CONTINUES UNTIL 6 PM FOR THE LAGUNA AND GULF
WATERS DUE TO STRONG WINDS AND HAZARDOUS SEAS. THE SMALL CRAFT
ADVISORY WILL LIKELY BE EXTENDED FOR THE LOWER TEXAS GULF WATERS
THROUGH TONIGHT FOR STRONG WINDS THIS EVENING AND ROUGH SEAS
OVERNIGHT.

&&

.PREV DISCUSSION... /ISSUED 739 AM CST MON MAR 3 2014/

DISCUSSION...MADE A FEW GRID CHANGES TO THE TEMPERATURE/DEWPOINTS
AND WINDS REFLECT CURRENT TRENDS AND OBSERVATIONS. BRO RADAR
INDICATES ELEVATED SHOWERS AND THUNDERSTORMS ACROSS THE WESTERN
AND NORTHERN RANCHLANDS THIS MORNING. CURRENT MUCAPE VALUES /800
TO 2000 J/KG/ TO SUPPORT ELEVATED CONVECTION THOUGH THIS MORNING.
WILL MENTION THUNDER THROUGH NOON GENERALLY ALONG AND WEST OF
INTERSTATE 69E/US HIGHWAY 77 CORRIDOR. THE REST OF THE FORECAST
LOOKS GOOD. TEXT PRODUCTS HAVE BEEN SENT.

PREV DISCUSSION... /ISSUED 538 AM CST MON MAR 3 2014/

DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.

AVIATION...LIFR CEILINGS WILL REMAIN OVER KBRO THROUGH THE EARLY
MORNING HOURS WITH CEILINGS AROUND 200FT. NORTH TO NE WINDS WILL
REMAIN BREEZE TO WINDY THROUGH MID DAY WITH GUSTS UP TO 30 KNOTS
POSSIBLE AND LIGHT RAIN AND DRIZZLE DEVELOPING DURING THE DAY.
CEILINGS WILL GRADUALLY RISE THIS AFTERNOON TO MVFR CONDITIONS BY
THIS EVENING ACROSS THE LOWER TEXAS COAST.

PREV DISCUSSION... /ISSUED 410 AM CST MON MAR 3 2014/

SHORT TERM /NOW THROUGH TUESDAY/...LATEST SATELLITE IMAGERY SHOWS
FRONT MOVING ACROSS THE LOWER VALLEY BACKING WINDS TO THE N AND NE
WITH STRONG GUSTS UP TO 25 MPH. STRONG PRESSURE GRADIENT WILL KEEP
WINDY CONDITIONS ACROSS THE CWA THROUGH EARLY MONDAY MORNING. A WIND
ADVISORY IS IN EFFECT FOR THE COASTAL AREAS THROUGH THE EARLY
MORNING HOURS. THIS NORTHERLY WINDS WILL MAKE TEMPERATURES FEEL INTO
THE LOW TO MID 20S ACROSS THE CWA SO A WIND CHILL ADVISORY IS IN ALSO
IN EFFECT THROUGH-OUT THE DAY. THE WINDS WILL BEGIN TO WEAKEN BY MID
DAY AS THE GRADIENT WEAKENS KEEPING WINDS BETWEEN 10 TO 15 MPH BY THE
LATE AFTERNOON. LIGHT RAIN AND DRIZZLE WILL GRADUALLY DEVELOP WITH
THIS FRONT FOR THE REMAINDER OF THE NIGHT AND INCREASE IN COVERAGE
AS THIS COLD AIR INTERACTS WITH THE MOISTURE ALREADY IN PLACE IN THE
EARLY MORNING HOURS. ACCUMULATIONS WILL BE VERY LIGHT WITH READINGS
LESS THAN FIVE TENTHS OF AN INCH. MODEL SOUNDINGS SHOW A PRONOUNCED
SUB-FREEZING LAYER JUST OFF THE SFC WITH A SUBSTANTIAL WARM LAYER
ABOVE IT FOR A COUPLE HOURS RIGHT AROUND SUNRISE. THIS WILL BRING
THE PRECIPITATION INITIALLY AS LIQUID RAINFALL FALLING INTO THE
SUBFREEZING LAYER. THAT LAYER MAY SUPERCOOLED THE DRIZZLE...BUT WONT
HAVE ENOUGH TIME TO COMPLETELY FREEZE IT. NOW ONCE THIS FALLS INTO
THE IMMEDIATE SURFACE LAYER...WHICH IS EXPECTED TO REMAIN ABOVE
FREEZING...IT WILL STAY AS LIQUID. NOW THERE MIGHT BE POTENTIAL FOR
A FEW SURFACES TO BRIEFLY HAVE SOME FREEZING GLAZE ON THEM AROUND
HBV RIGHT AROUND DAWN...BUT DUE TO THE FACT THAT MOST ITEMS WILL
HAVE BEEN SIGNIFICANTLY HEATED YESTERDAY...MOST OF THESE
ITEMS/SIGNS...FENCES...SMALLER TREE BRANCHES/ WILL STILL BE WARM
ENOUGH TO INHIBIT ANY ICE BEING ABLE TO ACCUMULATE ON THEM. BRIDGES
AND OVERPASSES AND LARGER EXPOSED ITEMS SHOULD REMAIN OK.

BY MONDAY EVENING ANOTHER UPPER LEVEL WAVE WITHIN THE FLOW
APPROACHES SOUTH TEXAS MONDAY EVENING INTO TUESDAY INCREASING
SHOWERS OVER THE COASTAL AREAS AND THE LOWER RGV. THIS WILL EXPAND
IN COVERAGE ACROSS THE CWA AS THE SHORTWAVE MOVES ACROSS THE AREA.
THE BEST POTENTIAL WILL BE CONCENTRATED ALONG THE COASTAL COUNTIES
AND THE COASTAL WATERS. NORTHERLY WINDS WILL PREVAIL INTO TUESDAY
KEEPING TEMPERATURES IN THE COOL SIDE BY SUNRISE WITH READINGS IN
THE MID 30S AND ALONG THE RIVER NEAR THE 40S. HIGH TEMPS TUESDAY
WILL REACH THE LOW 50S ACROSS THE BORDER WITH OVERCAST SKIES FOR
MOST OF THE DAY.

LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...SHORTWAVE 500MB TROUGH
ACROSS NORTHWEST GULF OF MEXICO TUESDAY WILL MOVE EASTWARD AS
ANOTHER TROUGH DIGS ACROSS THE CENTRAL UNITED STATES WEDNESDAY.
THE COASTAL TROUGH ALONG THE LOWER TEXAS COAST TUESDAY WILL MOVE
EASTWARD AS RESULT BRINGING AN END TO RAIN CHANCES ACROSS THE CWA
WEDNESDAY INTO THURSDAY AS DRIER AIR FILTERS INTO THE RIO GRANDE
VALLEY IN THE WAKE OF A FRONT THURS MORNING. 500MB TROUGH ACROSS
THE SOUTHEAST UNITED STATES WILL PROVIDE SUBSIDENCE ACROSS TEXAS
THURSDAY INTO FRIDAY BEFORE A 500MB TROUGH DEVELOPS ACROSS THE
WESTERN UNITED STATES BY THE END OF THE WEEK INTO THE WEEKEND.
THERE ARE CONSIDERABLE DIFFERENCES BETWEEN THE GLOBAL MODELS FOR
THE WEEKEND WITH THE ECMWF CUTTING OFF A 500MB LOW ACROSS NORTHERN
MEXICO AND THE GFS BRINGING THE TROUGH EASTWARD ACROSS TEXAS
SUNDAY. BOTH MODELS BRING A COLD FRONT THROUGH SOUTH TX LATE
SATURDAY BUT THE ECMWF IS SLIGHTLY WETTER THAN THE GFS. WILL GO
WITH A BLEND BETWEEN THE MEX AND ECX MOS THROUGH THE REST OF THE
FORECAST PERIOD FOR TEMPERATURES AND ALLCON MOS FOR POPS.

MARINE...
NOW THROUGH TUESDAY...AREAS OF FOG CONTINUE TO IMPACT THE
LOWER PORTIONS OF THE LAGUNA MADRE AND THE LOWER TEXAS GULF WATERS.
THIS FOG WILL IMPROVE AS THE FRONT MOVES ACROSS THE AREA AND NORTH
TO NORTHEAST WINDS INCREASE. THE NORTH WINDS WILL PRODUCE GALE FORCE
GUSTS WHICH WILL BUILD SEAS UP TO 8 TO 9 FEET TODAY. THERE IS A GALE
FORCE WINDS IN EFFECT FOR THE GULF WATERS THROUGH 9 AM AND A SMALL
CRAFT ADVISORY FROM 9 AM THROUGH 6 PM. THE WINDS WILL REMAIN BREEZE
OVER THE OFFSHORE WATERS KEEPING SEAS UP TO 7 FEET TONIGHT INTO
TUESDAY. A SMALL CRAFT WILL POSSIBLY BE EXTENDED THIS AFTERNOON FOR
TUESDAY.

TUESDAY NIGHT THROUGH FRIDAY...LIGHT TO MODERATE NORTHEAST WINDS
TUES NIGHT WILL VEER TO THE EAST AND DIMINISH WEDNESDAY AS LOW
PRESSURE DEVELOPS ACROSS WEST TEXAS. WINDS WILL SHIFT TO THE NORTH
AND INCREASE THURSDAY IN THE WAKE OF A COLD FRONT. MODERATE NORTH
WINDS THURSDAY WILL VEER TO THE SOUTHEAST FRIDAY AS HIGH PRESSURE
ACROSS THE NORTHWEST GULF OF MEXICO SHIFTS EASTWARD. SMALL CRAFT
ADVISORIES MAY BE NEEDED FOR THE COASTAL WATERS FRIDAY AS THE
PRESSURE GRADIENT INCREASES AC ROS THE LOWER TEXAS COAST.

&&

.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL  46  41  54  49 /  40  50  50  20
BROWNSVILLE          44  41  54  49 /  40  40  50  20
HARLINGEN            41  41  54  48 /  40  40  50  20
MCALLEN              41  39  50  47 /  40  40  50  20
RIO GRANDE CITY      40  38  50  47 /  40  30  30  10
SOUTH PADRE ISLAND   50  45  55  52 /  40  50  50  20

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...WIND CHILL ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR TXZ248>257.

GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR GMZ130-132-
     135-150-155-170-175.

&&

$$

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

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