Drought in Texas, December 31, 2013

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
1138 PM CST MON DEC 30 2013

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

&&

.AVIATION...STRONG UPPER TROUGH/STORM SYSTEM ACROSS NORTHWEST
MEXICO AND ITS ASSOCIATED 100+ KNOT JET STREAM EXTENDING OVER TEXAS
CONTINUES TO DRIVING WIDESPREAD OR CONTINUOUS PRECIPITATION FROM
MEXICO NORTHEAST ACROSS SOUTH TEXAS. THIS PATTERN TO PERSIST FOR
AT LEAST ANOTHER 18 TO 24 HOURS. FLYING CONDITIONS TO REMAIN POOR
WITH CEILINGS VARYING BETWEEN IFR AND MVFR OR 700 TO 1500 FEET AT
THE 3 REGIONAL AIRPORTS. DRIER AIR HAS WORKED ITS WAY INTO THE
NORTHERN AREAS OF DEEP SOUTH TEXAS RISING CIGS TO VFR. THERE HAS
BEEN SOME BRIEF BREAKS IN THE IFR/MVFR ACROSS THE SOUTH BUT IN THE
MOST PART CIGS AROUND 1000 FEET GIVE OR TAKE A FEW HUNDRED FEET
EITHER SIDE OF 1K IS LIKELY TO CONTINUE THROUGH TUESDAY. CONFIDENCE
IS BELOW AVERAGE IF ANY DRY AIR WORKS ITS WAY TO THE 3 TAFS SITES
WITH ALL MODEL GUIDANCE MAINTAINING THE LOWER CONDITIONS. TAFS
WILL REMAIN PESSIMISTIC THROUGH TONIGHT WITH NO LET UP IN THE RAIN
UNTIL THE STORM SYSTEM ACROSS NORTHWEST MEXICO WEAKENS OR MOVES
EASTWARD FASTER.

&&

.PREV DISCUSSION... /ISSUED 759 PM CST MON DEC 30 2013/

DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.

AVIATION...THE PCPN SHIELD OVER DEEP SOUTH TX HAS SLACKENED A BIT
WHILE ECHOES SOUTH OF THE RIO GRANDE AND OFFSHORE REMAIN PRETTY
EXTENSIVE. ALL OF THE ECHOES CONTINUE MOVING NORTHEAST AT A FAIRLY
STEADY PACE. THE 00Z BRO SOUNDING REMAINS VERY SATURATED WITH NW-
NE WINDS EVIDENT UP THROUGH AROUND 6 KFT WITH SW FLOW EVIDENT
ABOVE THIS LEVEL. THE 500 MB TROUGH TO OUR WEST WILL TAKE PLENTY
OF TIME BEFORE CLEARING THE REGION ON WED. MEAN RH FIELDS MAINTAIN
PRETTY HIGH MOISTURE LEVELS THROUGHOUT THE UPCOMING TAF PERIOD AND
BOTH THE MAV AND MET GUIDANCE MAINTAIN PRETTY HIGH POPS THROUGHOUT
THE NEXT 24 HOURS. MAV FORECAST CEILINGS LOOK PRETTY UNREALISTIC
KEEPING CEILINGS AFTER MVFR LEVELS AROUND 15KFT. NAM AND GFS LAMP
GUIDANCE LOOK MORE REPRESENTATIVE MAINTAINING GENERAL IFR
CONDITIONS THROUGHOUT THE MAJORITY OF THE UPCOMING TAF PERIOD. SO
OPTED TO GO WITH A BLEND OF THE LAMP AND MET GUIDANCE FOR THE
LOWER RGV AIRPORTS.

PREV DISCUSSION... /ISSUED 249 PM CST MON DEC 30 2013/

DISCUSSION...UPDATED FOR LATEST MARINE DISCUSSION BELOW.

MARINE...WEDNESDAY THROUGH SATURDAY...A BRIEF LULL IN HAZARDOUS
MARINE CONDITIONS IS EXPECTED LATE WEDNESDAY AS THE COASTAL TROUGH
MOVES NORTH AND EAST AWAY FROM THE COAST...RESULTING IN MODERATE
WINDS AND SEAS THAT SUBSIDE SLIGHTLY. THIS REPRIEVE IS SHORT LIVED
AS ANOTHER COLD FRONT SURGES ACROSS THE LOWER TEXAS COASTAL WATERS
THURSDAY...INCREASING WINDS AND SEAS TO SMALL CRAFT ADVISORY
CRITERIA ONCE AGAIN THURSDAY AND FRIDAY.

PREV DISCUSSION... /ISSUED 204 PM CST MON DEC 30 2013/

SHORT TERM /NOW THROUGH TUESDAY NIGHT/...CONSULTING THE IN-HOUSE
CLIMATOLOGY BINDER REVEALS THAT BRO EXPERIENCED RECORD RAINFALL OF
96 INCHES ON THIS DATE IN 1958...1.43 INCHES IN HRL IN 1986...AND
1.60 INCHES IN MFE ALSO IN 1986. SO FAR FOR TODAY...BRO HAS PICKED
UP 1.48 INCHES...1.45 INCHES IN HRL...AND .75 INCHES IN MFE. WHILE
A FORECAST UPDATE WAS MADE A COUPLE OF HOURS AGO REGARDING HIGH
TEMPERATURES FOR TODAY...VERY FEW OTHER CHANGES WERE MADE TO THE
FORECAST IN THE SHORT TERM.

TONIGHT...SCATTERED TO LIKELY PRECIPITATION CHANCES EXPECTED...AS A
SERIES OF DISTURBANCES RIDE OVERHEAD IN THE SOUTHWEST-TO-NORTHEAST
500 MB FLOW. LOW TEMPERATURES WILL BE JUST A FEW DEGREES COLDER THAN
EXPECTED HIGH TEMPERATURES FOR MONDAY...AND APPEAR TO BE ON TRACK
DUE TO OBSERVED DEWPOINT TEMPERATURES FALLING INTO THE MID 30S TO
AROUND 40 DEGREES AS OF THIS WRITING.

TUESDAY...NO SIGNIFICANT PATTERN CHANGE...EXCEPT HIGH PRESSURE AT
THE SURFACE BUILDS A LITTLE FARTHER INTO THE BRO CWFA. WITH THE
MID-LEVEL FLOW CONTINUING TO BE ORIENTED OUT OF MEXICO...SCATTERED
TO NUMEROUS BANDS OF RAINFALL WILL AFFECT THE RIO GRANDE VALLEY AND
ALL OF DEEP SOUTH TEXAS. HIGH TEMPERATURES FOR TOMORROW...UPPER 40S
TO AROUND 50 DEGREES...APPEAR REASONABLE FOR NOW...BUT INCOMING
SHIFTS WILL HAVE TO WATCH NEW MODEL GUIDANCE AND ADJUST ACCORDINGLY
ESPECIALLY WITH THE CLOUDS AND RAINFALL PREDICTED.

TUESDAY NIGHT...NO CHANGE. STILL EXPECTING RAINFALL WITH NO MAJOR
CHANGE IN THE OVERALL WEATHER PATTERN. LOW TEMPERATURES SHOULD BE
CLOSER TO NORMAL FOR THIS TIME OF YEAR.

LONG TERM /WEDNESDAY THROUGH MONDAY/...
WEDNESDAY MORNING WE WILL BE SITUATED ON THE RIGHT EXIT REGION OF A
SOUTHERN STREAM JET MAX EAST OF A TROUGH AXIS OVER NORTH CENTRAL
MEXICO. THIS WILL ENHANCE FURTHER CYCLOGENESIS IN THE WESTERN GULF
OF MEXICO AND KEEP A MODERATE ONSHORE EASTERLY FLOW IN PLACE UNDER
DECENT MID LEVEL ASCENT. CONTINUED MODEST RAINFALL CHANCES...NUDGING
THEM UP SLIGHTLY ON WEDNESDAY BASED ON TRENDS THAT KEEP THE LOW
LEVEL CYCLONE A LITTLE STRONGER AND CLOSER TO THE COAST...WITH A
SLIGHTLY LESS PROGRESSIVE MOVE OF THE UPPER TROUGH. BEST RAIN
CHANCES WILL BE IN THE EASTERN HALF OF THE AREA PEAKING OFF THE
COAST OF SOUTH PADRE ISLAND.

THE UPPER TROUGH DOES GET BOOTED EASTWARD WEDNESDAY NIGHT AS AN
ADVANCING POLAR JET AMPLIFIES THE TROUGH AND SHUNTS IT EASTWARD.
THIS MOVES THE SURFACE LOW NORTH AND THEN OFF TO OUR EAST AND RAIN
CHANCES DIMINISH PRETTY QUICKLY. HOWEVER THE KICKING JET MAX IS
PRETTY STRONG AND THE RESULTING TROUGH AMPLIFICATION BECOMES PRETTY
FORMIDABLE AND IT SENDS A RATHER ROBUST COLD FRONT THROUGH DURING
THE NIGHT. FRONT HAS DEEP SUPPORT ALOFT...UP TO AROUND 750MB WITH
RESPECTABLE COLD ADVECTION THROUGH THE LOWEST 200MB OF THE
ATMOSPHERE. THIS DRIES OUT OUR AIRMASS SIGNIFICANTLY AND WILL LIKELY
PRODUCE HAZARDOUS WINDS OFF THE COAST AND ON THE LAGUNA MADRE AND
CREATE BREEZY TO WINDY CONDITIONS OVER LAND WEDNESDAY NIGHT INTO
THURSDAY. TEMPERATURES WILL DROP RESPECTABLY...WITH A SOURCE AIRMASS
REGION IN MONTANA OF AROUND -6F AND LOWERED MAX TEMPS ON THURSDAY
INTO THE LOW 60S TO UPPER 50S. SUNSHINE SHOULD KEEP THE TEMPERATURES
AT THIS MORE MODERATE LEVEL BUT THERE IS GOING TO BE A LOT OF COLD
ADVECTION SO WE MAY STILL BE TOO WARM IN THE NEW FORECAST.

HIGH PRESSURE SLOWLY BUILDS IN FROM THE NORTHWEST BY THURSDAY NIGHT
AND LIGHT WINDS AND GENERALLY CLEAR SKIES WILL MAKE FOR A CHILLY
NIGHT ACROSS THE AREA WITH HIGHS ON THE RANCHLANDS IN THE MID TO
UPPER 30S AND MID TO UPPER 40S VALLEY.

WITH THE RIDGING ESTABLISHING WINDS SHIFT TO THE EAST ON FRIDAY AND
EVENTUALLY SOUTHEAST. FRIDAY WILL BE A LITTLE WARMER AND SATURDAY
MORE SO REBOUNDING INTO THE UPPER 60S TO LOW 70S. CLOUD COVER WILL
RETURN ON SATURDAY AS MOISTURE STREAMS BACK IN ON SOUTHWESTERLIES.
THERE WILL BE A SLIGHT CHANCE FOR SHOWERS IN THE MORNING HOURS.

MODEL DISCREPANCY REMAINS LARGE REGARDING A FRONTAL PASSAGE ON
SUNDAY HONING IN ON DETAILS REGARDING THE JET PATTERN IN THE PLAINS
THAT EVENTUALLY PROVIDES THE FORCING TO SEND THE FRONT THIS WAY.
ENSEMBLE MEMBERS SHOW A LARGE SPREAD AND LOW PREDICTABILITY WITH THE
ECMWF PREFERRING A DEEPER TROUGH AND MORE ROBUST FROPA...AND THE GFS
PREFERRING A MORE PROGRESSIVE/ZONAL UPPER PATTERN AND MORE OF A
WHIMPER IN TERMS OF FRONTAL PASSAGE. ENSEMBLE MEMBERS DO NOT QUITE
SHOW ANYTHING WITH THE INTENSITY OF THE ECMWF SOLUTION SO LEANED IN
THE DIRECTION OF THE GFS WITH A MODERATE FROPA...BRIEF COOL DOWN AND
EASTERLY RETURN FLOW SHORTLY THEREAFTER BUT THIS SOLUTION IS VERY
LOW CONFIDENCE.

WE ALSO WANT TO CONGRATULATE ALFREDO VEGA...A LONGSTANDING MEMBER
OF OUR ACE PUBLIC SERVICE UNIT ON HIS RETIREMENT EFFECTIVE WHEN HE
FINISHES HIS LAST SHIFT TONIGHT. A CAREER IN FEDERAL SERVICE
SPANNING MORE THAN 42 YEARS...38 WITH US IN THE NATIONAL WEATHER
SERVICE LAUNCHING SOME 9000 WEATHER BALLOONS FROM HERE TO COLD BAY
ALASKA! WE WILL HAVE A LOT OF SHOES TO FILL WITH HIS DEPARTURE.
WE WISH HIM THE BEST OF LUCK IN HIS RETIREMENT. /68-JGG/

MARINE...NOW THROUGH TUESDAY NIGHT...BUOY 42020 REPORTED NORTH
WINDS AROUND 21 KNOTS GUSTING TO AROUND 25 KNOTS WITH SEAS SLIGHTLY
UNDER 8 FEET WITH A PERIOD OF 7 SECONDS AT 12 CST/18 UTC. THE
PASSAGE OF A COLD FRONT THROUGH THE LOWER TEXAS COAST THIS MORNING
AND THE INTERACTION BETWEEN HIGH PRESSURE BUILDING INTO SOUTH
TEXAS AND PERSISTENT LOW PRESSURE OVER THE BAY OF CAMPECHE...WILL
PRODUCE ADVERSE WIND AND SEA CONDITIONS ALONG THE LOWER TEXAS COAST
THROUGH THE PERIOD. A SMALL CRAFT ADVISORY FOR WINDS IS IN EFFECT
FOR THE LAGUNA MADRE UNTIL 6 PM CST THIS EVENING...WITH ANOTHER
SMALL CRAFT ADVISORY IN EFFECT UNTIL 6 AM CST TUESDAY FOR THE GULF
OF MEXICO WATERS EAST OF PADRE ISLAND FROM 0 TO 60 NAUTICAL MILES
OFFSHORE. THE ADVISORY FOR THE ADJACENT GULF WATERS WILL LIKELY
NEED TO BE EXTENDED THROUGH AT LEAST TUESDAY NIGHT.

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 6 AM CST TUESDAY FOR GMZ150-155-170-
     175.

&&

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

59/51

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
940 PM CST MON DEC 30 2013

TXZ248>257-311200-
ZAPATA-JIM HOGG-BROOKS-KENEDY-STARR-HIDALGO-INLAND WILLACY-
INLAND CAMERON-COASTAL WILLACY-COASTAL CAMERON-
940 PM CST MON DEC 30 2013

THIS HAZARDOUS WEATHER OUTLOOK IS FOR DEEP SOUTH TEXAS.

.DAY ONE...REST OF TONIGHT.

LIGHT TO MODERATE RAIN COULD PRODUCE LOCALIZED PONDING ON ROADWAYS
AND POOR DRAINAGE AREAS TONIGHT. THE HEAVIEST RAINFALL WILL LIKELY
OCCUR OVER CAMERON...WILLACY...HIDALGO AND KENEDY COUNTIES WHERE AN
ADDITIONAL ONE HALF TO THREE QUARTERS OF AN INCH OF RAINFALL WILL BE
POSSIBLE THROUGH SUNRISE TOMORROW MORNING.

THERE IS A HIGH RISK OF RIP CURRENTS ALONG AREA BEACHES.

LOW WIND CHILLS FROM 30 TO 40 DEGREES WILL BE OCCUR TONIGHT DUE TO
THE COMBINATION OF THE NORTH WINDS AND LOW TEMPERATURE READINGS.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

WIND CHILLS WILL RANGE FROM 30 AND 40 DEGREES EARLY TUESDAY MORNING.

THE RIP CURRENT RISK WILL REMAIN ELEVATED TUESDAY THROUGH FRIDAY.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTER ACTIVATION WILL NOT BE NEEDED.

GMZ130-132-135-150-155-170-175-311200-
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-
940 PM CST MON DEC 30 2013

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

.DAY ONE...REST OF TONIGHT.

A SMALL CRAFT ADVISORY IS IN EFFECT FOR THE LOWER TEXAS GULF WATERS
UNTIL 6 AM CST TUESDAY.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

ADDITIONAL SMALL CRAFT ADVISORIES MAY BE NEEDED ALONG THE LOWER
TEXAS COASTAL WATERS FOR MUCH OF THE REMAINDER OF THIS WEEK.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTER ACTIVATION WILL NOT BE NEEDED.