Severe Thunderstorm Warning 7, NWS Houston/Galveston, TX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
608 PM CST TUE FEB 5 2008

.UPDATE...
UPDATING FORECAST TO BEEF UP POPS THIS EVENING RIGHT ALONG THE
DRYLINE. CLOSELY MONITORING SEVERE STORM OVER LAVACA COUNTY. ALSO
APPEARS THAT CONVECTION MAY BE BEGINNING TO EVOLVE FURTHER NORTH
OVER THE CWA. EXPECT THREAT FOR ISOLATED STRONG/SEVERE STORMS TO
PERSIST THROUGH ABOUT 9 PM...THEN WIND DOWN AS FRONT MOVES INTO
THE MORE STABLE/CAPPED AIRMASS NEAR THE COAST. DENSE SEA FOG WILL
PERSIST OVER GALVESTON BAY UNTIL AROUND MIDNIGHT WHEN THE FRONT
PASSES.

35/37/31

&&

.PREV DISCUSSION... /ISSUED 204 PM CST TUE FEB 5 2008/

DISCUSSION...
THE SEVERE WEATHER POTENTIAL FOR SE TX IS LOOKING RATHER
DIMINISHED THIS AFTERNOON. SOUNDINGS AT 18Z FOR LCH...FWD AND SHV
CONFIRM THAT CAPPING IS STRONGER ALONG THE COAST AND WEAKER
ACROSS N TX INTO NW LA. LATEST SFC OBS AND VISIBLE SATELLITE
TRENDS SHOW THE DRYLINE PUSHING THROUGH THE I-35 CORRIDOR IN
CENTRAL TX WITH CONVECTION INITIATING ALONG IT MAINLY FROM A
TEMPLE TO DALLAS LINE. POSSIBLE FOR THIS LINE TO FILL IN FARTHER
SOUTH WHICH WITH TIME COULD AFFECT AREAS NORTH OF A BRYAN TO
HUNTSVILLE LINE. SOUNDINGS ALSO SHOW RATHER STEEP LAPSE RATES
ABOVE THE CAP WHICH COULD SUPPORT STRONGER INSTABILITY. LOW LEVEL
WINDS HAVE VEERED SOME ACROSS THE AREA WITH VERY STRONG DEEP
LAYER SHEAR DUE TO 500MB WINDS AROUND 80KTS. MAIN THREATS WILL BE
STRAIGHT LINE WINDS AND POSSIBLY HAIL FROM THE STORMS. ANY
TORNADO THREAT WILL BE FARTHER NE FROM ARKLATEX REGION INTO MISS
VALLEY AS OUTLOOKED BY SPC. THE UPPER LOW CONTINUES TO PROGRESS
EAST OVER W TX AND WILL FURTHER HELP DESTABILIZE THE ATMOSPHERE
OVER N TX. COLD FRONT ALSO STILL BACK TRAILING FROM THE RED RIVER
INTO W TX. THE FRONT CONTINUES TO MAKE PROGRESS AND SHOULD OVER
TAKE THE DRYLINE LATER THIS EVENING. COLD FRONT SHOULD MAKE ITS
WAY THROUGH SE TX BETWEEN 01Z AND 04Z. FRONT WILL BE COMPLETELY
OFFSHORE BY 06Z WED.

WEDNESDAY WILL FEEL RELATIVELY COOL AS COMPARED TO THE LAST
COUPLE OF DAYS. SFC RIDGE WILL ALLOW FOR CLEAR SKIES FOR MOST OF
THE DAY. UPPER LEVEL PATTERN FROM THE 12Z GFS/ECMWF LOOK VERY
SIMILAR AS COMPARED TO YESTERDAY. NW FLOW ALOFT WILL ALLOW FOR A
COUPLE OF SHORTWAVE TROUGHS TO DROP THROUGH THE SOUTHERN PLAINS
AND NOT CAUSE MUCH CHANGE IN THE WEATHER FOR SE TX. THE FIRST
ROTATES THROUGH THURSDAY WITH A SECOND ON LATE FRIDAY. THIS WILL
ALLOW FOR RIDGING ALOFT AND FOR A SFC RIDGE TO SLIDE OUT OF
CANADA INTO THE MIDWEST ON SUNDAY. THIS SHOULD RE-ENFORCE
EASTERLY SFC FLOW SUNDAY AND KEEP TEMPS NEAR NORMAL. RETURN FLOW
SHOULD SET UP MONDAY WHICH MAY BRING BACK MOISTURE TO THE AREA.
RAIN CHANCES ARE EXPECTED MORE ON TUESDAY BUT THERE IS SOME
INCONSISTENCY BETWEEN THE GFS AND ECMWF ON HOW TO HANDLE THE NEXT
STRONG TROUGH. STILL PLENTY OF TIME TO DETERMINE DETAILS AND WILL
KEEP WITH 20 POPS AS BEFORE. THE TEMPERATURE FORECAST FOR THE
REST OF THE WEEK AND THE WEEKEND REMAINS RATHER CONSISTENT. TWEAK
TEMPS HERE AND THERE TO REFLECT SOME SLIGHTLY DIFFERENT TRENDS IN
MODELS. OVERALL NO REASON TO DEVIATE TOO MUCH FROM GUIDANCE.

OVERPECK/39

AVIATION...
COLD FRONT WILL SWEEP ACROSS SOUTHEAST TEXAS TONIGHT AND WILL BRING
AN END TO THE CLOUDS AND SEA FOG. UNTIL ITS ARRIVAL...WELL CONTINUE
TO CONTEND WITH MVFR CLOUDS ACROSS A LARGE PART OF THE AREA AND
IFR/LIFR SEA FOG VISIBILITIES IN AND AROUND GALVESTON BAY. SOME
DRIER AIR AND CLEARING SKIES IS CREEPING INTO OUR FAR SOUTHWESTERN
COUNTIES EARLY THIS AFTERNOON...BUT CLOUDS ARE TRYING TO BUILD ALONG
THE DRY LINE/COLD FRONT FURTHER OFF TO THE WEST. HAVE GENERALLY GONE
ALONG WITH A SHOT OF SHRA/TSRA LATER THIS AFTERNOON AND EARLY THIS
EVENING...THEN CLEARING SKIES FROM WEST TO EAST DURING THE EVENING
AND OVERNIGHT HOURS AS WINDS SWING AROUND TO THE SOUTHWEST AND THEN
TO THE NORTHWEST. FOR NOW...HAVE GOT SEA FOG HANGING AROUND THE
GALVESTON BAY AND GALVESTON ISLAND AREA THROUGH 03Z. WE MIGHT NEED
TO EXTEND THIS UNTIL AROUND 06Z. SKC TOMORROW  42

MARINE...
ONSHORE MARINE WINDS ARE GENERALLY RUNNING 15 TO 25 KNOTS EXCEPT
RIGHT ALONG THE IMMEDIATE COAST AND ACROSS PORTIONS OF GALVESTON BAY
WHERE SPEEDS ARE CLOSER TO 10 KNOTS. SEAS ARE AT 5 FEET AT THE
NEARSHORE WATER BUOY AND 10 FEET AT THE OFFSHORE WATER BUOY. WINDS
MAY WEAKEN A BIT LATER THIS AFTERNOON AND ON TOWARDS MIDNIGHT AS
THE COLD FRONT GETS CLOSER TO THE COAST. WINDS WILL SHIFT TO THE
NW AND NNW AFTER MIDNIGHT WITH 20 TO 25 KNOT SPEEDS POSSIBLE IN
BOTH THE NEARSHORE AND OFFSHORE WATERS BY SUNRISE. THESE SPEEDS
WILL QUICKLY COME DOWN STARTING MID MORNING AS HIGH PRESSURE
BUILDS ON IN. BY MID TO LATE AFTERNOON...BOTH NORTH WINDS AND SEAS
ARE LIKELY TO BE UNDER CAUTION CONDITIONS. NEXT FLAG OPPORTUNITY
WILL PROBABLY HOLD OFF UNTIL SATURDAY.

FOR TONIGHTS/TOMORROWS HAZARDS...WILL CARRY CAUTION FOR THE BAYS
THROUGH TOMORROW MORNING. FOR THE NEARSHORE WATERS...WILL CARRY
CAUTION FLAGS UNTIL MIDNIGHT AND AN ADVISORY FROM MIDNIGHT THROUGH
TOMORROW MORNING. FOR THE OFFSHORE WATERS...WILL CARRY ADVISORY
FLAGS ALL THE WAY THROUGH TOMORROW MORNING.  42

&&

.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL)      42  60  40  68  43 /  20   0   0   0   0
HOUSTON (IAH)              46  61  39  69  44 /  30   0   0   0   0
GALVESTON (GLS)            50  60  49  65  54 /  20   0   0   0   0

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION THROUGH WEDNESDAY MORNING
     FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY.

     SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 9 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 SHOULD EXERCISE CAUTION UNTIL MIDNIGHT CST TONIGHT
     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 9 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...35

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
532 PM CST TUE FEB 5 2008

GMZ330-335-TXZ163-164-176>179-195>200-210>214-226-227-235>238-
061300-
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-
532 PM CST TUE FEB 5 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST TEXAS.

.DAY ONE...TONIGHT

SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL AFFECT SOUTHEAST
TEXAS THIS EVENING AS A DRYLINE AND PACIFIC COLD FRONT INTERACT
WITH A MOIST AND UNSTABLE AIRMASS IN PLACE.

THE POTENTIAL EXISTS FOR ONE OR TWO STORMS TO BECOME
SEVERE...MAINLY WEST OF A LINE FROM LIVINGSTON TO HOUSTON TO
PALACIOS. THE PRIMARY SEVERE WEATHER THREATS WOULD BE LARGE HAIL
OR DAMAGING WIND. THE SEVERE THREAT SHOULD END BY 9 PM AS THE
AIRMASS STABILIZES AND THE FRONT HAS CLEARED MOST OF THE AREA.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

NO HAZARDOUS WEATHER IS EXPECTED.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS POSSIBLE THIS EVENING.