Wind Advisory 4, NWS Houston/Galveston, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
545 AM CST SAT MAR 7 2009

.DISCUSSION...
SEE AVIATION DISCUSSION BELOW.

&&

.AVIATION...
CEILING FORECAST A BIT TRICKY THIS MORNING...ACTUALLY FOR THIS
MORNING AND AGAIN TONIGHT. PLENTY OF LOW-LEVEL MOISTURE AVAILABLE
UNDER THE INVERSION. THE INVERSION WAS ACCENTUATED BY THE LOW-
LEVEL JET ABOVE 2000 FEET. MOST AREAS SOUTH OF THE BIG AIRPORTS
SCATTERED OR CLEARED OUT VERY EARLY THIS MORNING EVEN THOUGH THE
MODEL FORECASTS ARE SHOWING MVFR AND SPOTTY IFR CEILINGS. DECIDED
TO GO WITH THE CURRENT TRENDS IN THE FIRST FEW HOURS. BETWEEN 14Z
AND 17Z THE MVFR CEILINGS WILL LIFT. AS THE CLOUD DECK SCATTERS
OUT...GUSTY WINDS WILL DEVELOP ONCE MORE AROUND MIDDAY.

FOR TONIGHT...THE PROBLEM IS TIMING AND EXTENT OF THE LOW CLOUD
FORMATION. RELIED HEAVILY UPON PERSISTENCE...OR WHAT OCCURRED OVER
THE PAST 24 HOURS...AS THERE WILL NOT BE A MAJOR CHANGE IN THE
AIRMASS OR CONDITIONS.

40

&&

.PREV DISCUSSION... /ISSUED 258 AM CST SAT MAR 7 2009/

DISCUSSION...
ANOTHER WARM AND BREEZY DAY IS ON TAP FOR THE REGION. AT 08Z...LOW
PRESSURE WAS LOCATED OVER THE WESTERN HIGH PLAINS WITH HIGH
PRESSURE OVER THE SOUTHEAST U.S.. ONSHORE WINDS WILL CONTINUE TO
DRAW IN ABUNDANT LOW LEVEL MOISTURE. AREA SOUNDINGS STILL REMAIN
CAPPED BUT WOULD NOT BE SURPRISED IF A FEW STREAMER SHOWERS
DEVELOP UNDER THE CAP BEGINNING EARLY SUNDAY MORNING AND
CONTINUING THROUGH TUESDAY. NO REAL TRIGGER TO HANG YOUR HAT ON
AND FORECAST SOUNDINGS SHOW CAPPING TO CONTINUE SO WILL NOT GO
HIGHER THAN 20 POPS AT THIS TIME. TEMPS LOOK TO REMAIN
UNSEASONABLY WARM THROUGH TUESDAY. GRADIENT IS RATHER TIGHT TODAY
AND JUST LIKE YESTERDAY...WIND SPEEDS WILL APPROACH WIND ADVISORY
CRITERIA MAINLY WEST OF A MADISONVILLE TO FREEPORT LINE.

MODEL SOLUTIONS DIVERGE GREATLY BEGINNING WEDNESDAY. THE GFS HAS
SPED THE FRONT UP AND BRINGS IT THROUGH THE CWA BY WED 12Z. THE
ECMWF BRINGS THE FRONT TO THE COAST ON THURSDAY AND THEN STALLS
THE FRONT ALONG OR JUST OFF THE COAST. THE GFS AND ECMWF DIFFER
WITH THE UPPER LEVEL PATTERN AS THE GFS SEEMS TO BE MUCH TOO FAST
WITH AN UPPER LEVEL TROUGH AND IS MUCH FARTHER WEST WITH A SECOND
UPPER LEVEL TROUGH ALLOWING AN UPPER RIDGE TO BUILD OVER WEST
TEXAS. THE ECMWF MAINTAINS AN UPPER LOW OVER THE SOUTHWEST U.S.
THROUGH NEXT WEEKEND AND KEEPS SOUTHWEST WINDS ALOFT IN PLACE.
THE CANADIAN...NOGAPS AND UK SEEM TO SUPPORT THE SLOWER ECMWF
SOLUTION AND HAVE LEANED TO THE ECMWF SOLUTION. FEEL RAIN CHANCES
WILL BE HIGHEST BEHIND THE FRONT WHEN ISENTROPIC UPGLIDE WILL BE
MAXIMIZED. THE ECMWF SEEMS TO BE FOCUSING THE HIGHEST RAIN CHANCES
ALONG THE 850 MB BOUNDARY WHICH SHOULD REMAIN OVER THE NORTHERN
HALF OF THE REGION. HAVE TAPERED POPS HIGHEST NORTH...LOWER TOWARD
THE COAST. THE GFS IS CONSIDERABLY COOLER THAN THE ECMWF. LEANED
TOWARD THE SLIGHTLY WARMER GUIDANCE SINCE THE FRONT WILL HANG UP
NEAR THE COAST. 43

MARINE...
A COLD FRONT WILL APPROACH THE COASTAL AREAS DURING THE MID WEEK
PERIOD. HOWEVER...INDICATIONS ARE NOW THAT THE FRONT WILL STALL OUT
ALONG THE IMMEDIATE COAST BEFORE MOVING BACK NORTHWARD LATE IN THE
WEEK. TODAY THE SEAS WILL BE HIGH ENOUGH LATER THIS MORNING FOR AN
SCA. WINDS WILL DIMINISH LATER TODAY WHICH WILL HELP THE SEAS TO
SUBSIDE A BIT. THE PRESSURE GRADIENT LOOKS TO REMAIN TIGHT ENOUGH
FOR WINDS TO INCREASE AGAIN TONIGHT AND THERE MAY BE A NEED TO
EXTEND THE ADVISORY.

IF THE LATEST MODELS ARE CORRECT...EAST NORTHEAST WINDS WILL DEVELOP
AFTER WEDNESDAY AND PERSIST THROUGH THE LATE WEEK PERIOD. THIS
SCENARIO COULD LEAD TO TIDE LEVELS RISING ABOVE NORMAL. DEFINITELY
AN ITEM TO WATCH OUT FOR.

40

&&

.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL)      83  67  83  67  81 /  10  10  20  20  20
HOUSTON (IAH)              82  67  83  67  82 /  10  10  20  20  20
GALVESTON (GLS)            76  66  76  66  76 /  10  10  10  20  20

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE
     FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
     CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO
     FREEPORT 20 TO 60 NM.

     SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 6 AM CST EARLY THIS
     MORNING FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO
     THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM
     HIGH ISLAND TO FREEPORT 20 TO 60 NM.

&&

DISCUSSION...43
AVIATION/MARINE...40

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
614 AM CST SAT MAR 7 2009

GMZ330-335-TXZ163-164-176>179-195>200-210>214-226-227-235>238-
072100-
AUSTIN-BRAZORIA-BRAZOS-BURLESON-CHAMBERS-COLORADO-FORT BEND-
GALVESTON-GALVESTON BAY-GRIMES-HARRIS-HOUSTON-JACKSON-LIBERTY-
MADISON-MATAGORDA-MATAGORDA BAY-MONTGOMERY-POLK-SAN JACINTO-
TRINITY-WALKER-WALLER-WASHINGTON-WHARTON-
614 AM CST SAT MAR 7 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST TEXAS.

.DAY ONE...TODAY AND TONIGHT

SOUTH WINDS WILL INCREASE TO 15 TO 25 MPH THIS AFTERNOON. WIND
SPEEDS WILL AGAIN FLIRT WITH WIND ADVISORY CRITERIA BUT AT THIS
TIME SUSTAINED WINDS ARE EXPECTED TO REMAIN BELOW 25 MPH. THE
STRONGEST WINDS SHOULD BE WEST OF A MADISONVILLE TO FREEPORT LINE.

OTHERWISE NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED.