Severe Thunderstorm Warning 25, NWS Houston/Galveston, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
333 PM CDT TUE APR 26 2011

.DISCUSSION...
CONVECTION JUST BEGINNING TO DEVELOP NORTH AND NORTHWEST OF THE
AREA. SPC HAS ISSUED A TORNADO WATCH JUST TO THE NORTH OF THE
REGION. A LOW PRESSURE AREA WAS JUST BEGINNING TO DEVELOP
NORTHWEST OF WACO WITH A WITH A WARM FRONT EXTENDING TO THE
NORTHEAST. THUNDERSTORMS WILL INCREASE IN COVERAGE AND MOVE EAST
TONIGHT. THE NORTHERN THIRD OF SOUTHEAST TEXAS IS OUTLOOKED IN
SLIGHT RISK. THE QUESTION AGAIN IS CAP STRENGTH? WATER VAPOR
IMAGERY SHOWS A WELL DEVELOPED SHORT WAVE MOVING EAST AND FEEL
THIS FEATURE WILL SPUR ON ADDITIONAL DEVELOPMENT. JUST NOT VERY
CONFIDENT ON FAR SOUTH THIS AREA OF STORMS WILL MOVE. THE JET
STRUCTURE AGAIN FAVORS NE TX AS SE TX LIES IN A RIGHT FRONT QUAD.
WILL START WITH CHANCE POPS OVER THE NORTH THIRD AND MENTION
SEVERE WITH SLIGHTLY LOWER POPS TO THE SOUTH. FEEL THERE WILL
AGAIN BE A SHARP AREAL CUT OFF TO THE CONVECTION. TEMPS WILL
REMAIN ABOVE SEASONAL NORMALS TONIGHT WITH CLOUDS FILLING IN
OVERNIGHT. NAM 12 IS QUITE WARM ON WEDNESDAY OVER THE SOUTHWEST
PORTION OF THE AREA. BOTH THE GFS AND NAM HAVE DEW POINTS MIXING
OUT RESULTING IN VERY LOW HUMIDITY LEVELS. WILL MAINTAIN THE FIRE
WEATHER WATCH FOR NOW BUT FEEL RED FLAG CRITERIA WILL BE MET.
COOLER AND DRIER WEATHER WILL PREVAIL THROUGH THE END OF THE
MONTH. OVER THE WEEKEND...MOISTURE RETURNS ON STRONG SOUTH WINDS
ON SATURDAY. WARMER OVERNIGHT LOW TEMPERATURES CAN BE EXPECTED
SATURDAY NIGHT. A COLD FRONT WILL CROSS SOUTHEAST TEXAS LATE
SUNDAY OR MONDAY. BOTH THE GFS AND ECMWF BRING A FAIRLY DEEP
TROUGH ACROSS THE SOUTHERN PLAINS ON MONDAY. THE LIFT FROM THESE
TWO FEATURES SHOULD GIVE SOUTHEAST TEXAS A CHANCE OF RAIN BOTH
SUNDAY AND MONDAY. 43

&&

.MARINE...
ELEVATED GULF SEAS TO CONTINUE THROUGH TOMORROW AFTERNOON'S FRONTAL
PASSAGE. A PUCKERED UP INLAND PRESSURE GRADIENT DURING THE EVENING
HOURS SHOULD INCREASE LOCAL BAY AND NEARSHORE WINDS TO NEAR 20 KTS
SUSTAINED...WITH THE CURRENT SCEC LIFTING UP TO SCA THROUGH 12Z.
(SOUTH)WESTERLY WINDS FALLING RIGHT AHEAD OF THE BOUNDARY EARLY
TOMORROW MORNING WILL WAVER THESE WATERS BACK INTO A SCEC. ALTHOUGH
THERE WILL BE A BRIEF PICK UP IN WINDS AS THE FRONT CROSSES THE
COAST...BAY/NEAR SHORE GENERAL SCEC CONDITIONS SHOULD PREVAIL.
FURTHER OFFSHORE...SEAS IN THE 6 TO 9 FOOT RANGE WILL KEEP AN SCA IN
EFFECT THROUGH EARLY WEDNESDAY AFTERNOON. OFFSHORE WINDS AND
HEIGHTENED SEAS TO SETTLE DOWN FROM LATE THURSDAY THROUGH FRIDAY. A
TIGHTENED ONSHORE GRADIENT...PER LOWERING PANHANDLE PRESSURES...WILL
ONCE AGAIN STRENGTHEN ONSHORE FLOW BACK TO AT LEAST SCEC THROUGH THE
WEEKEND. 31

&&

.FIRE WEATHER....
WILL MAINTAIN THE FIRE WEATHER WATCH THROUGH THE NIGHT WITH AN
ANTICIPATION OF A RED FLAG BEING ISSUED BY THE MIDNIGHT CREW.
HUMIDITIES WILL LOWER TO AT (OR BELOW) 25% CRITERIA...WITH AFTERNOON
15-20 KT SUSTAINED NW-N WINDS. AS POST-FRONTAL DEW POINTS FALL INTO
THE UPPER 30S TO LOWER 40S...HUMIDITIES WILL FALL INTO THE TEENS TO
MIDDLE 20S ACROSS A GOOD MAJORITY OF THE REGION. LONG PERIOD
SUSTAINED 15-20 KT WINDS ARE STILL IN QUESTION AS HIGH CENTER
QUICKLY ADVANCES DOWN INTO CENTRAL TEXAS BY MID-DAY THUS KILLING LOW
LEVEL GRADIENT. AMPLE SUN AND HIGHER MID-LEVEL NW'ERLIES MIXING TO
SURFACE SHOULD COUNTERACT THIS WEAKENED GRADIENT. AN AREAWIDE RFW
MAY NOT BE NEEDED...BUT AS OF NOW...ANTICIPATE AT LEAST A CENTRAL
AND NORTHERN COUNTY RFW TO BE IN EFFECT TOMORROW AFTERNOON. 31

&&

.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL)      67  85  50  84  55 /  30  10   0   0   0
HOUSTON (IAH)              74  88  53  85  57 /  20  20   0   0   0
GALVESTON (GLS)            75  86  62  80  68 /  20  20   0   0   0

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY
     EVENING FOR THE FOLLOWING ZONES: AUSTIN...BRAZORIA...
     BRAZOS...BURLESON...CHAMBERS...COLORADO...FORT BEND...
     GALVESTON...GRIMES...HARRIS...HOUSTON...JACKSON...LIBERTY...
     MADISON...MATAGORDA...MONTGOMERY...POLK...SAN JACINTO...
     TRINITY...WALKER...WALLER...WASHINGTON...WHARTON.

GM...SMALL CRAFT ADVISORY FROM 1 AM TO 7 AM CDT WEDNESDAY 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 SHOULD EXERCISE CAUTION UNTIL 1 AM CDT WEDNESDAY 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 SHOULD EXERCISE CAUTION FROM WEDNESDAY MORNING
     THROUGH WEDNESDAY 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 UNTIL 7 PM CDT 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...43/31

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
339 PM CDT TUE APR 26 2011

TXZ163-164-176>179-195>200-210>214-226-227-235>238-270800-
AUSTIN-BRAZORIA-BRAZOS-BURLESON-CHAMBERS-COLORADO-FORT BEND-
GALVESTON-GRIMES-HARRIS-HOUSTON-JACKSON-LIBERTY-MADISON-MATAGORDA-
MONTGOMERY-POLK-SAN JACINTO-TRINITY-WALKER-WALLER-WASHINGTON-
WHARTON-
339 PM CDT TUE APR 26 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST TEXAS.

.DAY ONE...THIS AFTERNOON AND TONIGHT

AN UPPER LEVEL DISTURBANCE WILL TRIGGER SCATTERED SHOWERS AND
THUNDERSTORMS TONIGHT. THE STORMS WILL BE STRONG TO SEVERE WITH
DAMAGING WINDS AND LARGE HAIL...MAINLY NORTH OF A BRENHAM TO
HUNTSVILLE TO LIVINGSTON LINE. FURTHER SOUTH...A CAPPING INVERSION
WILL LIMIT THUNDERSTORM COVERAGE AND INTENSITY.

.DAY TWO...WEDNESDAY

MUCH DRIER AIR WILL MOVE INTO THE REGION IN THE WAKE OF A COLD FRONT.
SUNNY SKIES...BRISK WINDS...AND VERY LOW RELATIVE HUMIDITY VALUES
WILL PRODUCE ELEVATED FIRE DANGER CONDITIONS ACROSS THE REGION. A
FIRE WEATHER WATCH IS IN EFFECT FOR WEDNESDAY.

.DAYS THREE THROUGH SEVEN...THURSDAY THROUGH MONDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS POSSIBLE TONIGHT FOR THE NORTHERN PORTIONS
OF SOUTHEAST TEXAS.