Wind Advisory 2, NWS Houston/Galveston, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
601 AM CST TUE FEB 10 2009

.AVIATION...
MOSTLY MVFR CEILINGS ARE EXPECTED AREAWIDE TODAY AHEAD OF A COLD FRONT
THAT MOVES THROUGH THE AREA OVERNIGHT TONIGHT. MODERATE/STRONG SOUTH
WINDS ARE REFLECTED IN THE 12Z TAFS WITH MOST LOCATIONS CARRYING
15 TO 20 KNOTS WITH GUSTS CLOSE TO 30 KNOTS. WEST WINDS 10 TO 15 KNOTS
CAN BE EXPECTED AFTER THE FRONTAL PASSAGE. MAINLY -RA/-SHRA CAN BE EXPECTED
THIS MORNING FOLLOWED BY A BREAK IN THE AFTERNOON. A LINE OF SHRA/TSRA
IS EXPECTED OVERNIGHT WITH THE PASSAGE OF THE COLD FRONT.  42
&&

.PREV DISCUSSION... /ISSUED 417 AM CST TUE FEB 10 2009/

DISCUSSION...
MOSAIC CR LOOP CONTINUE TO INDICATE SCATTERED -SHRA MOVING ACROSS
CENTRAL AND NORTHEAST SECTIONS OF CWFA EARLY THIS MORNING.
PRESSURE GRADIENT REMAINING QUITE TIGHT TODAY AND INTO THE EVENING
RESULTING IN BRISK GUSTY SOUTHERLY WINDS. UPPER LEVEL LOW OVER UTAH
WILL RAPIDLY MOVE TO NORTHWEST TEXAS BY TONIGHT BRINGING WIDESPREAD
LIFT ACROSS THE REGION ESPECIALLY OVER NORTH TEXAS. AIR MASS BECOMING
MORE UNSTABLE LATER THIS AFTERNOON. CAPES/LIS INCREASING JUST
AHEAD OF FRONT WHEN IT MOVES ACROSS OUR REGION TONIGHT. HELICITY VALUES
QUITE IMPRESSIVE AS PER MODEL SOUNDINGS. FRONT IS EXPECTED TO APPROACH
NORTHWEST ZONES AROUND MIDNIGHT AND SHOULD REACH COAST CLOSE TO OR
JUST BEFORE 12Z WEDNESDAY MORNING. WEAK CAPPING IS INDICATED PRIOR TO
FROPA BUT FRONTAL FORCING SHOULD BREAK THIS. SPC INDICATE MODERATE RISK
OVER NORTHEAST TEXAS TODAY THROUGH TONIGHT WITH OUR REGION UNDER SLIGHT
RISK. WITH LESS CAPPING NORTHERN ZONES BELIEVE (FOR NOW) THAT
REGION SHOULD HAVE HIGHER CHANCES OF STORMS BECOMING SEVERE
TONIGHT AND WE INDICATED THIS IN OUR ZFPHGX. MUCH DRIER AIR WILL USHERED
BY THIS FRONT ON WEDNESDAY. TEMPERATURES HOWEVER WILL BE ABOVE
SEASONAL NORMAL VALUES. OVERNIGHT TEMPERATURES WILL BE CLOSE TO SEASONAL
VALUES WEDNESDAY NIGHT WITH DRY AIR IN PLACE AND RELATIVELY LIGHT
WINDS LEADING TO RADIATIONAL COOLING. HIGH PRESSURE MOVING EAST OF
REGION AND FALLING PRESSURES OVER WESTERN HIGH PLAINS WILL RESULT
IN ONSHORE FLOW RETURNING TO OUR REGION LATER ON THURSDAY. AN UPPER
LEVEL DISTURBANCE WILL MOVE ACROSS THE MID SECTION OF CONUS AND
ENERGY FROM THIS SYSTEM WILL REMAIN MAINLY NORTH OF OUR CWFA. A
COLD FRONT IS INDICATED TO MOVE ACROSS OUR REGION FRIDAY. WE SHALL KEEP
POPS (FOR NOW) AT 20 PERCENT BUT THIS PROBABLY WILL ADJUSTED
UPWARD THE NEXT 2 DAYS. GFS INDICATE INCREASING ISENTROPIC LIFT LATER
IN THE COMING WEEKEND WITH LOW LEVEL EASTERLY FLOW OVER OUR REGION
AND PASSING IMPULSES IN THE UPPER LEVEL WSW FLOW. ANOTHER FRONT IS
INDICATED BY BOTH GFS AND ECMWF TO MOVE ACROSS OUR REGION ON TUESDAY.
37

MARINE...
MODERATE TO STRONG ONSHORE WINDS ALONG WITH INCREASING SEAS WILL
PREVAIL TODAY AND TONIGHT. FLAGS ARE A LITTLE MESSY. FOR THE BAYS...
HAVE CAUTION THROUGH 3 PM THIS AFTERNOON THEN ADVISORY FLAGS UNTIL 3
AM TOMORROW MORNING. FOR THE NEARSHORE WATERS...HAVE CAUTION THROUGH
3 PM THIS AFTERNOON THEN ADVISORY FLAGS UNTIL 6 AM TOMORROW MORNING.
FOR THE OFFSHORE WATERS...AN ADVISORY IS CURRENTLY IN EFFECT AND
WILL CONTINUE UNTIL AT LEAST 6 AM TOMORROW MORNING. WIND SPEEDS ARE
STILL EXPECTED TO PEAK SOME TIME TONIGHT AHEAD OF AN APPROACHING
PACIFIC COLD FRONT. WAVE HEIGHTS WILL LIKELY TOP OUT SOMEWHERE
BETWEEN 10 AND 15 FEET BEFORE THE FRONT MOVES ON THROUGH. WE STILL
COULD SEE PERIODS OF SEA FOG DEVELOP BEFORE THE FRONT COMES ON
THROUGH. A LINE OF SHOWERS AND THUNDERSTORMS ARE EXPECTED ALONG AND
AHEAD OF THE FRONT AS IT RACES WEST TO EAST THROUGH THE REGION LATE
TONIGHT AND EARLY TOMORROW MORNING (FRONTAL PASSAGE TIMING LOOKS
SOMETHING LIKE BETWEEN 1 AM AND 3 AM FOR MATAGORDA BAY... BETWEEN
3 AM AND 5 AM FOR GALVESTON BAY...AND THEN EAST OF OUR GULF WATERS
BETWEEN 7 AM AND 9 AM). OFFSHORE WINDS BEHIND THE FRONT WEAKEN IN
THE AFTERNOON AS HIGH PRESSURE SETTLES OVER THE AREA. A LIGHT TO
MODERATE ONSHORE FLOW DEVELOPS ON THURSDAY AND THURSDAY NIGHT AHEAD
OF THE NEXT COLD FRONT THAT IS EXPECTED TO MOVE THROUGH THE AREA
FRIDAY EVENING.  42

FIRE WEATHER...
FROM WEDNESDAY MORNING THROUGH EARLY WEDNESDAY EVENING...RELATIVE
HUMIDITIES VALUES IN A 15 TO 25 PERCENT RANGE ARE ANTICIPATED ACROSS
MUCH OF SOUTHEAST TEXAS IN THE WAKE OF A PASSING PACIFIC COLD FRONT.
WIND SPEEDS ARE NOT EXPECTED TO REACH RED FLAG WARNING CRITERIA
ACROSS INLAND LOCATIONS...SO A FIRE WEATHER WATCH IS NOT NEEDED. IF
THE WIND FORECAST FOR WEDNESDAY BECOMES A LITTLE STRONGER ACROSS THE
INLAND COUNTIES...A FIRE WEATHER WATCH AND/OR A RED FLAG WARNING
MIGHT BE NEEDED. IT IS A DIFFERENT STORY FOR THE COASTAL COUNTIES.
FOR THIS AREA...THERE IS NO WIND CRITERIA. WITH EXCEPTIONALLY DRY
CONDITIONS LIKELY...A FIRE WEATHER WATCH WILL BE ISSUED FOR
BRAZORIA...GALVESTON...JACKSON AND MATAGORDA COUNTIES FROM 9 AM
THROUGH 7 PM (CHAMBERS COUNTY IS LEFT OUT FOR NOW DUE TO SLIGHTLY
HIGHER ANTICIPATED RELATIVE HUMIDITY VALUES). THIS WATCH WILL LIKELY
BE UPGRADED TO A RED FLAG WARNING EARLY ON WEDNESDAY MORNING.   42

&&

.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL)      74  51  76  44  74 /  30  60  10   0  10
HOUSTON (IAH)              74  56  73  45  73 /  30  60  20   0  10
GALVESTON (GLS)            71  60  71  55  67 /  20  60  20   0  10

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY
     EVENING FOR THE FOLLOWING ZONES: BRAZORIA...GALVESTON...
     JACKSON...MATAGORDA.

GM...SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 3 AM CST
     WEDNESDAY FOR THE FOLLOWING ZONES: GALVESTON BAY...
     MATAGORDA BAY.

     SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 3 PM CST THIS
     AFTERNOON FOR THE FOLLOWING ZONES: GALVESTON BAY...
     MATAGORDA BAY...WATERS FROM FREEPORT TO THE MATAGORDA SHIP
     CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT
     20 NM.

     SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 6 AM CST
     WEDNESDAY FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO
     THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH
     ISLAND TO FREEPORT OUT 20 NM.

     SMALL CRAFT ADVISORY UNTIL 6 AM CST WEDNESDAY 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...37
AVIATION/MARINE/FIRE...42

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
434 AM CST TUE FEB 10 2009

GMZ330-335-350-355-370-375-TXZ163-164-176>179-195>200-210>214-226-
227-235>238-111200-
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-
WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM-
WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM-
WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM-
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM-WHARTON-
434 AM CST TUE FEB 10 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST TEXAS.

.DAY ONE...TODAY AND TONIGHT

THE PRESSURE GRADIENT ACROSS THE REGION WILL REMAIN TIGHT
RESULTING IN BRISK AND GUSTY SOUTHERLY WINDS MAINLY DURING THE
LATE MORNING THROUGH THE EVENING HOURS. EXPECT WINDS OF 15 TO
25 MILES AN HOUR WITH OCCASIONAL HIGHER GUSTS.

A STRONG UPPER LEVEL DISTURBANCE AND ASSOCIATED PACIFIC COLD FRONT
WILL CROSS THE AREA TONIGHT. SCATTERED THUNDERSTORMS ARE EXPECTED TO
DEVELOP BEGINNING LATE THIS AFTERNOON...EVOLVING INTO A SQUALL
LINE THAT WILL AFFECT PORTIONS OF SOUTHEAST TEXAS AFTER MIDNIGHT. DUE
TO STRONG SHEAR IN THE LOW LEVELS OF THE ATMOSPHERE THE POTENTIAL
EXISTS FOR SOME OF THE STORMS TO BECOME SEVERE. THE PRIMARY RISK
AREA WILL BE TO THE NORTH OF A LINE FROM BRENHAM TO NEW WAVERLY
TO LIVINGSTON. THE PRIMARY SEVERE WEATHER THREATS WILL BE
DAMAGING WINDS AND HAIL...WITH THE POTENTIAL FOR ISOLATED
TORNADOES. A CAPPING INVERSION MAY LIMIT THE SOUTHERN EXTENT OF
THE SQUALL LINE.

.DAY TWO...WEDNESDAY...

A FIRE WEATHER WATCH WILL BE IN EFFECT FOR BRAZORIA...GALVESTON...
JACKSON AND MATAGORDA COUNTIES...FROM WEDNESDAY MORNING THROUGH
WEDNESDAY EVENING.

THE COMBINATION OF DRY FUELS AND VERY LOW HUMIDITY LEVELS WILL SET THE
STAGE FOR THE POSSIBILITY OF RAPID FIRE GROWTH IN THE WAKE OF A
COLD FRONT. RELATIVE HUMIDITY VALUES ARE EXPECTED TO FALL BELOW 20
PERCENT AROUND MID MORNING AND PERSIST BELOW 20 PERCENT UNTIL
AROUND SUNSET.

.DAYS THREE THROUGH SEVEN...THURSDAY THROUGH MONDAY

HAZARDOUS WEATHER IS NOT EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED LATE TUESDAY AFTERNOON AND
NIGHT...MAINLY NORTH OF A BRENHAM TO NEW WAVERLY TO LIVINGSTON
LINE.