Severe Thunderstorm Warning 71, NWS Houston/Galveston, TX

SOUTHEAST TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
900 PM CDT WED MAY 3 2000

MY APOLOGIES FOR THE LATE DISCUSSION BUT TECHNOLOGY PROBLEMS HAVE
PREVENTED NEW DATA FROM ARRIVING. HAVE NO UPPER AIR DATA...HEIGHT
FIELDS ETC. A RATHER BUMPY START TO THE NIGHT OVER NW HOUSTON (SEE
LSRHOU FOR DETAILS) BUT THIGS ARE EXPECTED TO REMAIN QUIET FOR THE
BULK OF THE NIGHT. A COMPLICATED SURFACE PATTERN SHAPING UP AS A
SURFACE LOW RESIDES OVER SOUTHERN ARKANSAS WITH A STATIONARY FRONT
OVER NORTH LA AND N TEXAS. A WEAK SFC TROUGH OR OUTFLOW RESIDES FROM
LFK TO AUS. SFC DEW POINTS ARE IN THE UPPER 60S TO LOWER 70S. IR AND
WV IMAGERY REVEALS ANOTHER S/WV ROTATING AROUND A PERSISTENT UPPER
LEVEL LOW OVER OK. THIS FEATURE WILL APPROACH SE TX LATE TONIGHT OR
MORE LIKELY TOMORROW MORNING. FEEL THAT THE AREA WILL BE
SUFFICIENTLY UNSTABLE WITH MOISTURE POOLING AND COOLER TEMPS ALOFT
TO WARRANT CURRENT WORDING OF SEVERE IN THE ZONES. MAIN ISSUE IS
TIMING AND SINCE MUCH OF THIS ACTIVITY IS DEPENDENT ON MESO-SCALE
BOUNDARIES...WELL TIMING IS DIFFICULT AT BEST. AM LEANING TOWARD THE
12Z ETA SOLUTION WHICH PAINTS A RATHER STORMY PICTURE FOR THURSDAY.
WILL CLEAN UP EVENING WORDING IN ZONES...BUT NO MAJOR CHANGES
PLANNED. WL ALSO FRESHEN UP SPS TO OUTLINE SEVERE AND HEAVY RAIN
THREAT.

.KHGX...NONE.

43/45

PRELIMS...
CLL TE 065/082 065/083 065 643
IAH TE 068/083 070/0L85 071 553
GLS TB 072/080 074/081 074 363

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
712 PM CDT WED MAY 03 2000

TIME(CDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0540 PM    SPRING BRANCH             TX   1 INCH HAIL
05/03/00   HARRIS                         NEAR IH610 AND H290.
                                          REPORTED BY PUBLIC.

0545 PM    3 E SPRING BRANCH         TX   WIND DAMAGE
05/03/00   HARRIS                         SILBER AND I-10
                                          BILLBOARD DOWN AND
                                          DETOURING TRAFFIC. .
                                          REPORTED BY EMERGENCY
                                          MANAGEMENT.

0548 PM    2 ENE SPRING BRANCH       TX   WIND DAMAGE
05/03/00   HARRIS                         TREES DOWN BLOCKING
                                          TRAFFIC FROM CHANNEL 13
                                          HELICOPTER. REPORTED BY
                                          MEDIA.

0548 PM    SPRING BRANCH             TX   .75 INCH HAIL
05/03/00   HARRIS                         AT HARRIS COUNTY
                                          EMERGENCY MANAGEMENT
                                          TRANSTAR BUILDING.
                                          REPORTED BY EMERGENCY
                                          MANAGEMENT.

TXZ163-164-040800-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1025 PM CDT WED MAY 3 2000

...SEVERE THUNDERSTORM WATCH IN EFFECT FOR HOUSTON AND TRINITY
COUNTIES TIL 3 AM...

A COMBINATION OF COOL THUNDERSTORM OUTFLOW BOUNDARIES NORTH OF THE
WATCH AREA MOVING SLOWLY SOUTHWARD...AN UNSTABLE AIRMASS AND WEAK
UPPER LEVEL DISTURBANCE IN THE JETSTREAM WILL LEAD TO A THREAT OF
SEVERE WEATHER OVER AND NEAR THE WATCH AREA.

LATE THIS EVENING STRONG TO SEVERE THUNDERSTORMS HAD DEVELOPED ALONG
AN OUTFLOW BOUNDARY FROM JACKSONVILLE TO PALESTINE TO FAIRFIELD.
THESE STORMS HAVE BEEN SLOW MOVING AND HAVE HAD A HISTORY OF
PRODUCING LARGE HAIL. REMEMBER SEVERE THUNDERSTORMS PRODUCE
LARGE HAIL AND DAMAGING WIND IN EXCESS OF 55 MPH...DEADLY LIGHTNING
AND VERY HEAVY RAIN...AND CAN PRODUCE TORNADOES SOMETIMES WITH LITTLE
ADVANCE NOTICE.

MONITOR NOAA WEATHER RADIO OR OTHER RELIABLE WEATHER NEWS SOURCES FOR
THE LATEST WARNINGS AND STATEMENTS.

TXZ163-164-176>179-195>200-210>214-226-227-235>238-041030-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1105 PM CDT WED MAY 3 2000

...SLIGHT RISK OF SEVERE STORMS AND HEAVY RAIN LATE TONIGHT THROUGH
THURSDAY AFTERNOON...

THERE IS A SLIGHT RISK OF SEVERE STORMS AND HEAVY RAIN FROM LATE
TONIGHT THROUGH THURSDAY AFTERNOON FOR ALL OF SOUTHEAST TEXAS. THE
PRIMARY SEVERE WEATHER HAZARDS ARE DAMAGING WINDS AND LARGE HAIL.

AT 1030 PM...SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WERE
DEVELOPING RAPIDLY OVER NORTHEAST AND NORTH-CENTRAL TEXAS. THIS AREA
OF STORMS IS FORECAST TO DRIFT SLOWLY SOUTHEAST OVERNIGHT AND AFFECT
AREAS GENERALLY NORTH OF A BRENHAM TO LIVINGSTON LINE. THE BEST
INSTABILITIES AND BEST CHANCE FOR SEVERE WEATHER IS NORTH OF A
COLLEGE STATION TO TRINITY LINE.

AN UPPER LEVEL DISTURBANCE ROTATING AROUND A PERSISTENT UPPER LEVEL
LOW PRESSURE SYSTEM OVER OKLAHOMA WILL INITIATE ADDITIONAL
THUNDERSTORM ACTIVITY OVER CENTRAL AND SOUTHERN PORTIONS OF
SOUTHEAST TEXAS THURSDAY MORNING INTO THURSDAY AFTERNOON.
INSTABILITY PARAMETERS REACH THEIR ZENITH AT THE TIME OF MAXIMUM
DAYTIME HEATING WHICH SHOULD CULMINATE IN ANOTHER ROUND OF STRONG
TO SEVERE THUNDERSTORMS.

MOISTURE LEVELS ARE ALSO FORECAST TO INCREASE ON THURSDAY WHICH
SHOULD YIELD SOME RATHER IMPRESSIVE RAINFALL TOTALS. SINCE MAY
1...SOME PARTS OF SOUTHEAST TEXAS HAVE RECEIVED IN EXCESS OF 7
INCHES OF RAIN. A FLASH FLOOD WATCH MAY BE REQUIRED FOR THURSDAY IF
CURRENT FORECAST TRENDS PERSIST. SOME AREAS ACROSS SOUTHEAST TEXAS
WHICH ARE VULNERABLE TO HEAVY RAIN INCLUDE NORTHERN HARRIS COUNTY...
BRENHAM TO HUNTSVILLE...AREAS NORTHEAST OF CONROE AND CENTRAL AND
SOUTHERN BRAZORIA INTO WESTERN GALVESTON COUNTY.

THIS IS A RAPIDLY DEVELOPING WEATHER SITUATION. ONLY SLIGHT CHANGES
IN IN VERTICAL MOISTURE VALUES...MID-LEVEL TEMPERATURES AND WINDS
COULD PRODUCE RADICALLY DIFFERENT CONDITIONS. STAY TUNED TO NOAA
WEATHER RADIO FOR FURTHER UPDATES AND POSSIBLE WEATHER WATCHES OR
WARNINGS.