Severe Thunderstorm Warning 33, NWS Houston/Galveston, TX

SOUTHEAST TEXAS FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
310 PM CST THU MAR 13 2003

HAVE ADJUSTED POPS FOR 1ST PERIOD TO CHANCE CENTRAL ZONES THIS EVENING
AS AIR MASS STILL UNSTABLE ENOUGH FOR CONVECTION AHEAD OF UPPER
TROUGH. WILL ALSO MENTION ISOLATED EARLY EVENING SHRA/TSRA NORTHERN
ZONES.

37/47

145 PM DISCUSSION...
THUNDERSTORMS CONTINUE TO REDEVELOP OVER CHAMBERS COUNTY PAST TWO HOURS
DUMPING 3 TO 6 INCHES ALONG INTERSTATE 10 CORRIDOR BETWEEN MONT BELVIEU
AND HANKAMER. CONVECTION OVER CWFA MAINLY CONFINED ALONG AND SOUTH
OF LIBERTY...EAGLE LAKE LINE. 850 MB TROUGH LINE WILL GRADUALLY SHIFT
TOWARDS THE COAST BY THIS EVENING SHIFING STRONGER STORMS TO THE
COASTAL WATERS. WEAK SUBSIDENCE EXPECTED OVER REGION LATER TONIGHT AS
BACKSIDE OF UPPER TROUGH APPROACHES. WE DO NOT EXPECT WIDESPREAD FOG
TONIGHT AS DRIER AIR SLOWLY FILTER IN OVERNIGHT W/LIGHT NORTHEAST
WINDS. COASTAL SECTIONS...HOWEVER MAY SEE A REDEVELOPMENT DESPITE
ONGOING MIXING AT THIS TIME. BUT FOR NOW WE WILL MENTION AREAS OF
FOG CENTRAL AND SOUTH FOR TONIGHT. EVENING SHIFT WILL HAVE TO CLOSELY
MONITOR DENSE FOG POTENTIAL AND ADVISORY MAY STILL HAVE TO BE ISSUED
LATER THIS EVENING. PW VALUES LOWERING TO AN INCH OR LESS FRIDAY
WITH DRYING TREND CONTINUING THROUGH THE WEEKEND. GFS INDICATE SOME
MOISTURE INCREASE WESTERN ZONES SUNDAY AS ISENTROPIC LIFT PICKS UP
OVER CENTRAL TEXAS. CHANCE OF PRECIP RETURNING MONDAY IN RESPONSE TO
APPROACHING AND DEVELOPING UPPER TROUGH FROM WESTERN CONUS. HIGHLY
AMPLIFIED UPPER TROUGH MOVING ACROSS CONUS TUESDAY AS PREVIOUSLY
ADVERTISED. TROUGH LINE WILL BE EAST OF REGION WEDNESDAY WITH RESULTANT
DRYING TREND. LAST TWO DAYS OF EXTENDED FORECAST SHOULD BE PRECIP
FREE. MARINE REGION WILL SEE CONVECTION DIMINISHING LATE TONIGHT AND
EARY FRIDAY. OTHERWISE...NO FLAGS ANTICIPATED FOR THE NEXT FEW DAYS.

37/47

.HGX...SEVERE THUNDERSTORM WATCH TIL 2 PM THIS AFTERNOON FOR
       PORTIONS OF SOUTHEAST TEXAS.

CLL BB 057/078 051/078 054 2-
IAH BB 059/077 053/078 056 31
GLS BB 062/072 061/073 062 41

TXZ163-164-176>179-195>200-210>214-226-227-235>238-141300-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
700 AM CST THU MAR 13 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST TEXAS.

...SEVERE THUNDERSTORMS AND LOCALLY HEAVY RAINFALL POSSIBLE TODAY AND
THIS EVENING ACROSS ALL OF SOUTHEAST TEXAS...

.DAY ONE...TODAY AND TONIGHT.

A DENSE FOG ADVISORY IS IN EFFECT UNTIL 10 AM FOR AREAS GENERALLY
ALONG AND SOUTH OF A LINE FROM LIVINGSTON TO CONROE TO BELLVILLE.

A VERY MOIST AND UNSTABLE ATMOSPHERE IS IN PLACE OVER SOUTHEAST TEXAS
TODAY. AN APPROACHING UPPER LEVEL DISTURBANCE AND BOUNDARY FROM
THUNDERSTORMS ACROSS NORTHERN PORTIONS OF SOUTHEAST TEXAS THIS
MORNING WILL TRIGGER THUNDERSTORM DEVELOPMENT OVER THE AREA TODAY.
SEVERE THUNDERSTORMS ARE POSSIBLE DUE TO THE VERY COLD TEMPERATURES
AND DRY AIR IN THE MIDDLE LAYER OF THE ATMOSPHERE. THE PRIMARY
SEVERE WEATHER THREATS WILL BE LARGE HAIL AND DAMAGING WIND GUSTS.

LOCALLY HEAVY RAINFALL WILL BE A THREAT DUE TO SLOW MOVING STORMS AND
VERY HIGH MOISTURE LEVELS. RAINFALL AMOUNTS ARE EXPECTED TO AVERAGE A
HALF TO ONE INCH ACROSS THE AREA WITH ISOLATED AMOUNTS OF THREE INCHES
POSSIBLE.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.
NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION MAY BE REQUIRED LATER TODAY.