Small Craft Advisory for Winds 1, NWS Brownsville, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
548 PM CST SAT DEC 31 2011

.DISCUSSION...SEE AVIATION DISCUSSION FOR 00Z TAFS.

&&

.AVIATION...EXPECTING DENSE FOG TO REFORM OR MOVE INLAND FROM THE
GULF OF MEXICO ONCE WINDS DIMINISH. SOME STRATUS IS FORECAST TO
DEVELOP IN ADVANCE OF THE FOG WHICH MAY DELAY THE ONSET OF THE
MOST DENSE FOG. VISIBILITIES ARE HOWEVER EXPECTED TO FALL BELOW
ONE HALF MILE AROUND OR SHORTLY AFTER MIDNIGHT AT KBRO AND KHRL
AND SHORTLY AFTER AT KMFE. THE COASTAL REACHES ARE SOCKED IN AND
WILL REMAIN IN THE DENSE FOG UNTIL A COLD FRONT MOVES THROUGH
SUNDAY MORNING. RAIN CHANCES INCREASE ALONG AND BEHIND THE FRONT
ESPECIALLY AS IT NEARS THE RIO GRANDE RIVER SUNDAY MORNING. VSBY
AND CIGS TO STEADILY RISE DURING THE DAY SUNDAY AS THE COLD FRONT
MOVES OFFSHORE AND HIGH PRESSURE BUILDS INTO THE VALLEY.

AN ISOLATED THUNDERSTORM OR TWO IS POSSIBLE WITH HIGH DEW POINTS
AND THE ATMOSPHERE BECOMING UNSTABLE. THUNDER IS NOT IN THE TAF AT
THIS TIME WITH CHANCES AT AROUND 10 TO 15 PERCENT. NORTH WINDS TO
INCREASE BEHIND THE FRONT WITH GUSTS UP TO 25 KNOTS POSSIBLE.

&&

.PREV DISCUSSION... /ISSUED 235 PM CST SAT DEC 31 2011/

SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...THE MAIN CONCERN IN
THE SHORT TERM PORTION OF THE FORECAST WILL ONCE AGAIN BE FOG.
MOSTLY CLEAR SKIES WILL COMBINE WITH LIGHT WINDS AND MOIST
ATMOSPHERIC CONDITIONS TO PRODUCE WIDESPREAD DENSE FOG ACROSS DEEP
SOUTH TEXAS AND THE RIO GRANDE VALLEY TONIGHT...ESPECIALLY BETWEEN
MIDNIGHT AND 6 AM CST SUNDAY...AND A DENSE FOG ADVISORY MAY BE
NEEDED FOR ALL OR PORTIONS OF THE BRO CWFA TONIGHT IN RESPONSE TO
THE FOG AND THE REDUCED VISIBILITIES. THE SLOW PASSAGE OF A COLD
FRONT FROM NORTH TO SOUTH BETWEEN 3 AM CST AND 9 AM CST SUNDAY
WILL CAUSE AN INCREASE IN WINDS FROM THE NORTH...ESPECIALLY DURING
POST-SUNRISE HOURS SUNDAY... ALLOWING THE FOG TO BE SCOURED OUT.
ISOLATED TO SCATTERED SHOWERS WILL ACCOMPANY THE INITIAL PASSAGE
OF THE FRONT...WITH TEMPERATURES COOLING IN ITS WAKE FOR SUNDAY
AND SUNDAY NIGHT.

LONG TERM /MONDAY THROUGH SATURDAY/...WEAK TO MODERATE 500 MB
RIDGING WILL GRADUALLY BUILD OVER THE U.S./MEXICO BORDER REGION
THROUGH TUE. A MID LEVEL SHORT WAVE WILL THEN TRACK OVER THE
BORDER REGION NEXT WEEK THEN EXITING THE REGION LATE NEXT WEEK.
THE MODEL HANDLING OF THIS FEATURE RAISES SOME UNCERTAINTY
QUESTIONS AS ECMWF/GFS AND CMC ALL REFLECT VARIOUS TIMING
DIFFERENCES IN THE EASTWARD PROGRESSION OF THIS FEATURE. THE CMC
IS THE FASTEST WITH THIS FEATURE FOLLOWED BY THE ECMWF WITH THE
GFS COMING IN THE SLOWEST CLEARING THE TROUGH EAST OF DEEP SOUTH
TEXAS LATE FRI. OTHER DIFFERENCES ALSO SHOW UP BETWEEN THE MODELS
CONCERNING THE AMOUNT OF MOISTURE ASSOCIATED THE PASSAGE OF THIS
FEATURE. BOTH THE CMC AND ECMWF MAINTAIN A FAIRLY DRY PASSAGE OF
THIS TROUGH WHILE THE GFS IS THE WETTEST WITH THE MEX MOS FOR THUR
AND FRI COMING IN WITH 20 TO 30 % POPS. BELIEVE THAT THE HIGHER
GFS POPS ARE LIKELY DUE TO THE SLOWER MOVEMENT OFF THE 500 MB
TROUGH WHICH WOULD IN TURN ALLOW FOR BETTER MOISTURE ADVECTION
OVER THE REGION. SINCE THE ECMWF AND THE CMC ARE IN BETTER
AGREEMENT AND THE GFS APPEARS TO BE THE ODD MODEL OUT WILL GO
BELOW MEX MOS POPS IN DAYS 3 TO 7. FOR TEMPS WILL CONTINUE TO
UNDERCUT THE MEX TEMPS FOR MON AND TUES AND WILL THEN LEAN CLOSER
TO MEX TEMPS AFTERWARDS. THE OVERALL CONFIDENCE FOR THE 3 TO 7 DAY
RANGE FORECAST WORDING IS ABOVE AVERAGE FOR TEMPS AND NEAR AVERAGE
FOR POPS.

MARINE...TONIGHT THROUGH SUNDAY NIGHT...BUOY 42020 REPORTED SOUTH-
SOUTHWEST WINDS AROUND 6 KNOTS GUSTING TO AROUND 8 KNOTS WITH SEAS
SLIGHTLY UNDER 1.5 FEET WITH A PERIOD OF 5 SECONDS AT 11 CST/17 UTC.
BENIGN WIND AND SEA CONDITIONS ARE EXPECTED ALONG THE LOWER TEXAS
COAST TONIGHT. HOWEVER...THE APPROACH OF A COLD FRONT WILL CAUSE
WINDS TO DIMINISH...AND WIDESPREAD DENSE FOG MAY DEVELOP OVER THE
LAGUNA MADRE AND GULF OF MEXICO WATERS EAST OF PADRE ISLAND FROM 0
TO 60 NAUTICAL MILES OFFSHORE IN RESPONSE TO THE LIGHT WINDS...
MOSTLY CLEAR SKIES...AND MOIST ATMOSPHERIC CONDITIONS. THE PASSAGE
OF A COLD FRONT AROUND SUNRISE SUNDAY MORNING WILL INCREASE WINDS
AND SEAS ALONG THE LOWER TEXAS COAST...SWEEPING THE FOG AWAY IN THE
MORNING HOURS. A SMALL CRAFT ADVISORY WILL LIKELY BE POSTED TONIGHT
FOR ALL OR PORTIONS OF THE ADJACENT COASTAL WATERS OF DEEP SOUTH
TEXAS IN ANTICIPATION OF THE STRONG WINDS AND ROUGH SEAS ON SUNDAY
THROUGH SUNDAY NIGHT.

MONDAY THROUGH THURSDAY...SOME SCA CONDITIONS MAY BE LINGERING
INTO MONDAY IN THE WAKE OF THE SUNDAY FRONT...BUT A LIGHTER PGF WILL
ALLOW FOR CALMER MARINE CONDITIONS INTO TUES THROUGH THURS TIME
FRAME.

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...DENSE FOG ADVISORY UNTIL 9 AM CST SUNDAY FOR GMZ130-132-135.

     DENSE FOG ADVISORY UNTIL 9 AM CST SUNDAY FOR GMZ150-155-170-175.

&&

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

59...AVIATION/SHORT TERM
63...LONG TERM
VEGA...GRAPHICASTS

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
1120 AM CST SAT DEC 31 2011

GMZ130-132-135-150-155-170-175-011200-
LAGUNA MADRE FROM THE PORT OF BROWNSVILLE TO THE ARROYO COLORADO-
LAGUNA MADRE FROM THE ARROYO COLORADO TO 5 NM NORTH OF PORT
MANSFIELD TX-
LAGUNA MADRE FROM 5 NM NORTH OF PORT MANSFIELD TO BAFFIN BAY TX-
COASTAL WATERS FROM PORT MANSFIELD TO THE RIO GRANDE OUT 20 NM-
COASTAL WATERS FROM BAFFIN BAY TO PORT MANSFIELD OUT 20 NM-
WATERS FROM PORT MANSFIELD TO THE RIO GRANDE EXTENDING FROM 20 TO
60 NM-
WATERS FROM BAFFIN BAY TO PORT MANSFIELD EXTENDING FROM 20 TO
60 NM-
1120 AM CST SAT DEC 31 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE GULF OF MEXICO AND THE
LAGUNA MADRE.

.DAY ONE...TODAY AND TONIGHT.

PATCHY FOG WILL AFFECT THE ADJACENT COASTAL WATERS OF DEEP SOUTH
TEXAS AND THE RIO GRANDE VALLEY THROUGH THIS AFTERNOON. THE FOG WILL
BECOME MORE WIDESPREAD AND DENSE TONIGHT AS A STRONG COLD FRONT
APPROACHES THE LOWER TEXAS COAST.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

SMALL CRAFT ADVISORIES WILL BE NEEDED FOR THE COASTAL WATERS
SUNDAY THROUGH MONDAY AS WINDS AND SEAS INCREASE IN THE WAKE OF
A COLD FRONT MOVING OFFSHORE THE LOWER TEXAS COAST SUNDAY MORNING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED.

TXZ250-251-253>257-011200-
BROOKS-KENEDY-HIDALGO-INLAND WILLACY-INLAND CAMERON-
COASTAL WILLACY-COASTAL CAMERON-
1120 AM CST SAT DEC 31 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR DEEP SOUTH TEXAS.

.DAY ONE...TODAY AND TONIGHT.

WIDESPREAD FOG...WITH SOME ISOLATED AREAS OF DENSE FOG...IS LIKELY
THROUGH THE MORNING HOURS. WIDESPREAD DENSE FOG WILL DEVELOP
TONIGHT BEFORE A STRONG COLD FRONT APPROACHES THE LOWER RIO GRANDE
VALLEY.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

DENSE FOG WILL CONTINUE TO DEVELOP ACROSS THE AREA EARLY SUNDAY BEFORE
A COLD FRONT MOVES THROUGH THE LOWER RIO GRANDE VALLEY SUNDAY MORNING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED.

TXZ248-249-252-011200-
ZAPATA-JIM HOGG-STARR-
1120 AM CST SAT DEC 31 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR DEEP SOUTH TEXAS.

.DAY ONE...TODAY AND TONIGHT.

AREAS OF FOG...SOME LOCALLY DENSE...WILL CONTINUE TO DEVELOP THIS
MORNING REDUCING VISIBILITIES TO LESS THAN A MILE. FOG WILL
REDEVELOP LATE TONIGHT BEFORE A STRONG COLD FRONT APPROACHES THE
AREA.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

AREAS OF FOG...SOME LOCALLY DENSE...WILL CONTINUE TO DEVELOP EARLY
SUNDAY BEFORE A STRONG COLD FRONT MOVES THROUGH THE AREA.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED.