Tornado Warning 40, NWS Houston/Galveston, TX

SOUTHEAST TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
228 PM CST SUN DEC 16 2001

SHOWER AND THUNDERSTORM COVERAGE AND INTENSITY HAS BEGUN TO INCREASE
ACROSS PORTIONS OF SOUTHEAST TEXAS THIS AFTERNOON. AT THIS TIME...
THE GREATEST CONCENTRATION IS STILL UP IN FTWS COUNTY WARNING AREA
WHERE THE BEST TRAINING IS OCCURRING. AS THE UPPER LOW NOW OUT IN
WEST TEXAS CONTINUES TO MOVE TO THE EAST...MID AND UPPER LEVEL
FORCING IS EXPECTED TO INCREASE ACROSS OUR AREA...ESPECIALLY IN OUR
NORTHERN ZONES CLOSER TO THE WARM FRONTAL BOUNDARY. THIS WILL RESULT
IN A GREATER THREAT FOR SEVERE THUNDERSTORMS DUE TO PRETTY DECENT
SHEAR. STILL THINK WE CAN GET SOME SEVERE THUNDERSTORMS TO DEVELOP
BEHIND THE MAIN SQUALL LINE THAT IS EXPECTED TO DEVELOP LATER THIS
AFTERNOON AND THIS EVENING. LAPSE RATES WILL BE STEEPENING AS THE
UPPER LOW PROGRESSES CLOSER TO OUR AREA...AND OUR EXTREMELY MOIST
AND UNSTABLE AIRMASS MAY BECOME MORE SUPPORTIVE OF SEVERE STORMS.
WILL KEEP THE MENTION OF SEVERE STORMS AND LOCALLY HEAVY RAINFALL IN
ALL ZONES FOR TONIGHT. SEVERE THREAT WILL BE GONE BY MORNING...BUT
IT IS STILL POSSIBLE SOME SHOWERS MAY LINGER ACROSS THE AREA AROUND
AND SHORTLY AFTER SUNRISE. AFTER MONDAY...DO NOT EXPECT THE RETURN
FLOW TO BE SUFFICIENT FOR ANY POPS WITH THE NEXT FRONTAL PASSAGE ON
WEDNESDAY. THIS FRONT WILL REINFORCE OUR COOL NIGHTS AND MILD DAYS.
THEN BEGINNING ON FRIDAY...A RETURN FLOW DOES BEGIN AS THE NEXT
UPPER LOW DEVELOPS OUT WEST. THERE IS MUCH UNCERTAINTY AS TO HOW
STRONG/HOW DEEP/HOW FAST THIS NEXT UPPER LOW WILL BE. FOR NOW...WILL
CONTINUE TO CALL FOR MOSTLY CLOUDY SKIES AND A CHANCE OF SHOWERS AND
THUNDERSTORMS FRIDAY THROUGH SUNDAY. LOOKS LIKE A MUCH COLDER AND
DRIER AIRMASS MIGHT BE HERE IN TIME FOR THE WEEK OF CHRISTMAS.

42/35/39

.HGX...TORNADO WATCH IN EFFECT TIL 7 PM FOR NORTHERN COUNTIES.
       SCA ALL WATERS TONIGHT.

PRELIMS...
CLL BU 048/063 038/066 042 810
IAH BU 052/064 040/066 042 820
GLS BU 057/062 048/064 052 830

TXZ163-164-176-177-198-170100-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
200 PM CST SUN DEC 16 2001

...TORNADO WATCH IN EFFECT UNTIL 700 PM CST...

A TORNADO WATCH IS IN EFFECT FOR PARTS OF SOUTHEAST TEXAS UNTIL 700
PM THIS EVENING. THE WATCH COVERS PARTS OF EAST TEXAS...IN THE
VICINITY OF A WARM FRONT...NEAR WHICH THUNDERSTORMS ARE EXPECTED TO
INTENSIFY.

THE FOLLOWING COUNTIES ARE INCLUDED IN THE WATCH...GRIMES...
HOUSTON...MADISON...TRINITY...AND WALKER.

THUNDERSTORMS HAVE BEGUN DEVELOPING ACROSS PORTIONS OF EAST TEXAS...
IN ADVANCE OF AN APPROACHING UPPER-LEVEL TROUGH. THE INCREASED LIFT
ASSOCIATED WITH THE TROUGH SHOULD ALLOW THE STORMS TO INCREASE IN
INTENSITY AND AREAL COVERAGE. THE SURFACE FRONT...STRONG LOW-LEVEL
WINDS...THE MOVEMENT OF THE UPPER TROUGH...AS WELL AS THE SHEAR
RESULTING FROM THESE FEATURES...WILL CREATE AN ENVIRONMENT FAVORABLE
FOR ROTATING STORMS. SOME OF THE THUNDERSTORMS TO THE WEST HAVE ALREADY
SHOWN SIGNS OF ROTATION.

THIS MEANS SEVERE THUNDERSTORMS...CAPABLE OF PRODUCING TORNADOES...
ARE POSSIBLE...IN AND NEAR THE WATCH AREA. BE ALERT FOR DAMAGING
WINDS AND LARGE HAIL IN THUNDERSTORMS THIS AFTERNOON. IF YOU ARE IN
THE PATH OF A SEVERE THUNDERSTORM OR TORNADO...MOVE INSIDE TO A
REINFORCED STRUCTURE AWAY FROM WINDOWS. REPORT DAMAGING WINDS AND
LARGE HAIL TO LOCAL LAW ENFORCEMENT...AND ASK THEM TO RELAY THE
MESSAGE TO THE NATIONAL WEATHER SERVICE.

ALSO BE ALERT FOR HEAVY RAIN THAT WILL CAUSE HIGH STANDING WATER ON
ROADS AND IN AREAS OF POOR DRAINAGE. DO NOT DRIVE INTO AREAS WITH HIGH
WATER.

A COLD FRONT WILL PASS THROUGH THE REGION TONIGHT...ENDING THE
PRECIPITATION. DRIER AND COOLER WEATHER WILL ACCOMPANY THE ARRIVAL
OF THE WORKWEEK.

39

GMZ335-TXZ163-164-176>179-195>200-210>214-227-238-170500-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
631 PM CST SUN DEC 16 2001

A TORNADO WATCH HAS BEEN ISSUED FOR FOR THE NORTHERN PORTIONS OF
SOUTHEAST TEXAS...GENERALLY ALONG AND NORTH OF A LINE FROM COLUMBUS TO
RICHMOND TO HOUSTON TO GALVESTON. THE TORNADO WATCH WILL BE IN EFFECT
TILL 11 PM.

WHEN THUNDERSTORMS ARE OCCURRING...MOVE INDOORS.  DO NOT STAND BY
WINDOWS.  UNLESS IT IS AN EMERGENCY...AVOID USING TELEPHONES AND
ELECTRICAL APPLIANCES UNTIL THE STORM HAS PASSED.  DAMAGING WIND...
LARGE HAIL...ISOLATED BRIEF TORNADOES AND VERY HEAVY RAIN ARE POSSIBLE
IN SEVERE THUNDERSTORMS.

REMEMBER A WATCH MEANS CONDITIONS ARE FAVORABLE FOR THE DEVELOPMENT
SEVERE WEATHER...A WARNING MEANS SEVERE WEATHER IS IMMINENT OR
ALREADY OCCURRING.

THE FOLLOWING COUNTIES ARE IN THE WATCH. HOUSTON...TRINITY...POLK...
MADISON...TYLER...WALKER...BRAZOS...SAN JACINTO...GRIMES...BURLESON...
MONTGOMERY...LIBERTY...WASHINGTON...WALLER...HARRIS...AUSTIN...
COLORADO...FORT BEND...GALVESTON...AND CHAMBERS.

RESIDENTS ACROSS SOUTHEAST TEXAS ARE STRONGLY URGED TO MONITOR NOAA
WEATHER RADIO AND LOCAL NEWS SOURCES AND BE PREPARED TO TAKE ACTION IN
CASE WARNINGS ARE ISSUED.