Severe Thunderstorm Warning 94, NWS Houston/Galveston, TX

SOUTHEAST TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
235 PM CDT THU JUN 21 2001

SCATTERED CONVECTION OVER CWFA THIS AFTERNOON. SURFACE PRESSURE
GRADIENT QUITE FLAT. COLD FRONT EXACT POSITION HARD TO PINPOINT BUT
LOWER THAN 70 DEWPOINTS EVIDENT NW OF DFW GRADUALLY FALLING TO THE
50S OVER THE PANHANDLE. 12Z RUN OF ETA CONTINUE TO SHOW STRONG UPPER
LEVEL DIVERGENCE FIELD (INDUCED BY RIGHT ENTRANCE REGION) MOVING OVER
CWFA OVERNIGHT TONIGHT BUT WEAKENING RAPIDLY TOWARDS MORNING AS JET
CORE MOVES FARTHER TO THE NE. LOW LEVEL INFLOW FROM GULF RELATIVELY
WEAK DURING THIS PERIOD. AVN SHOWS PW VALUES JUST AHEAD OF FRONTAL
BOUNDARY NEAR 1.9 INCHES WHILE ETA IS LOWER NEAR 1.7 INCHES. CAPE
QUITE HIGH NEAR 3000 J/KG. MESO-ETA INDICATE E-W AXIS OF NEAR 1 INCH
PRECIP SWINGING SOUTHWARD BUT PRECIP FIELD (IN CONJUNCTION W/UPPER
LEVEL DIV FIELD) BECOMING DIFFUSE/WEAKENING RAPIDLY AFTER 22/09Z.
THIS MAKE SENSE IN LIGHT OF WEAK INFLOW FIELD AND MAIN UPPER LEVEL
ENERGY MAINLY STAYING FAR NE OF CWFA. 700 MB TROUGH LINE SHOULD BE
NEAR COAST LINE BY 22/12Z. PW VALUES PROGGED BY MESO-ETA TO DROP
NEAR AN INCH N AND CENTRAL ZONES BY FRI AFTERNOON. FRONT EXPECTED TO
WASH OUT FRIDAY NIGHT. THE WEEKEND LOOKS DRY. RETURN FLOW ON SUNDAY
WILL GRADUALLY UP THE MOISTURE LEVELS ENOUGH FOR POSSIBLE SEA BREEZE
CONVECTION COASTAL AND POSSIBLY CENTRAL ZONES ON MONDAY. MRF HINTS AT
INCREASING DEPTH OF MOISTURE FIELD (S-SE FLOW) MID AND LATTER PART
OF NEXT WEEK. MARINE PACKAGE BENIGN WITH NO FLAGS.

.HGX...NONE.

37/46/48

PRELIMS...
CLL BU 069/089 065/091 068 610
IAH BU 071/090 067/091 069 530
GLS EB 077/087 075/087 077 341

TXZ163-164-176>179-195>200-210>213-226-227-235-212059-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1040 AM CDT THU JUN 21 2001

...AREAS OF MODERATE TO HEAVY RAIN POSSIBLE INLAND TONIGHT...

A COLD FRONT WILL MOVE SOUTH ACROSS SOUTHEAST TEXAS TONIGHT. AS IT
APPROACHES THE AREA...IT WILL ENCOUNTER A MOIST AND UNSTABLE
AIRMASS. THIS WILL SET THE STAGE FOR SHOWERS AND THUNDERSTORMS.
BECAUSE STEERING CURRENTS IN THE ATMOSPHERE ARE LIGHT...THE
THUNDERSTORMS WILL MOVE SLOWLY...AND SOME WILL PRODUCE HEAVY RAIN.

THE FRONT WILL WEAKEN A BIT AS IT MOVES SOUTH. THEREFORE...IT APPEARS
AT THIS TIME THAT THE HEAVIEST RAINS WILL FALL ALONG AND NORTH OF A
LINE FROM LAKE LIVINGSTON TO COLUMBUS. 1 TO 3 INCHES OF RAIN IS
POSSIBLE IN THIS AREA. THIS COULD PRODUCE HIGH STANDING WATER IN AREAS
OF POOR DRAINAGE AND COULD BRING SOME SMALL STREAMS AND CREEKS TO
NEAR BANKFULL.

FURTHER SOUTH IN SPOTS SUCH AS LIBERTY...METRO HOUSTON AND WHARTON...
AMOUNTS SHOULD BE IN THE 1/2 TO ONE AND A HALF INCH RANGE...WITH
ISOLATED TOTALS TO 3 INCHES. THIS WILL NOT BE SUFFICIENT TO BRING THE
HOUSTON AREA BAYOU SYSTEM TO FLOOD LEVELS...BUT COULD PRODUCE HIGH
SgTANDING WATER ON LOW LYING STREETS AND FEEDER ROADS.

LOOK FOR SKIES TO GRADUALLY CLEAR FROM THE NORTH BEHIND THE FRONT
FRIDAY AND FRIDAY NIGHT. SLIGHTLY LOWER HUMIDITY LEVELS WILL ALSO
FOLLOW THE FRONT AND WILL REMAIN THROUGH SATURDAY.