Severe Thunderstorm Warning 63, NWS Houston/Galveston, TX

SOUTHEAST TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
911 PM CDT MON MAY 1 2000

UPPER LOW WAS CURRENTLY OVER THE CENTRAL KS/OK BORDER.  SHORTWAVE
TROUGH WAS ALSO PUSHING AROUND THE SOUTHERN SIDE OF THE LOW...MOVING
INTO SOUTHERN TEXAS.  AREA SOUNDINGS...INCLUDING THE ACARS/MAPS
SOUNDING FOR IAH...ALL SHOW CAPES NEAR OR EXCEEDING 3000 FOR MUCH OF
SETX.  WITH THIS IN MIND FEEL THAT THE HIGH POPS FOR THE AREA ARE
WARRANTED...INCLUDING THE MENTION OF SEVERE AND HEAVY RAINFALL.
STRONG THUNDERSTORMS WERE DEVELOPING JUST WEST OF GRK AT THE MOMENT.
THESE STORMS WERE DEVELOPING ALONG A SURFACE TROUGH/OUTFLOW BOUNDARY.
SURFACE DEWPOINTS ALONG AND AHEAD OF THE BOUNDARY WERE IN THE MID 60S.
ALSO...SOUTHEASTERLY WINDS WERE FEEDING GULF MOISTURE INTO THE
DEVELOPING STORMS.  A SIDE NOTE...THE HGX VWP WAS SHOWING SOUTHWEST
WINDS NEAR THE SURFACE...MORE THAN LIKELY THE RESULT OF MIGRATING
BIRDS CONTAMINATING THE ALGORITHM RESULTS.

SO...THE CONCLUSION OF THE MATTER IS THAT ANOTHER ROUND OF
THUNDERSTORMS ARE EXPECTED.  WILL NOT GO WITH A FLASH FLOOD WATCH AT
THIS TIME...THOUGH RAINFALL AMOUNTS COULD REACH 1 INCH OR SO OVER A
WIDE AREA.  LOCATIONS THAT LOOK TO GET THE HEAVIER RAIN AMOUNTS WILL
BE THE FAR NORTHERN COUNTIES OF THE FORECAST AREA.

TEMPERATURES AND WINDS ARE THE MOST DIFFICULT OF THE VARIABLES TO
FORECAST TONIGHT.  GIVEN THE CURRENT DEWPOINTS FEEL THAT THE FORECAST
MINS ARE OKAY.  WINDS ARE ANOTHER MATTER.  VARIABLE TO SOUTHEAST WINDS
SHOULD OCCUR AHEAD OF THE THUNDERSTORMS...WITH NORTH WINDS IN ITS
WAKE.

WILL ONLY MAKE MINOR CHANGES TO THE COASTAL FORECAST.

.KHGX...NONE.

PL-40
45

TXZ163-164-176>179-195>200-210>214-226-227-235>238-021000-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
640 PM CDT MON MAY 1 2000

...SLIGHT RISK OF SEVERE THUNDERSTORMS AND HEAVY RAINFALL THREAT
ACROSS PORTIONS OF SOUTHEAST TEXAS TONIGHT INTO TUESDAY MORNING...

A SLOW MOVING UPPER LEVEL STORM SYSTEM THAT WAS OVER OKLAHOMA EARLY
THIS EVENING WILL SLOWLY DRIFT TO THE SOUTH-SOUTHEAST OVER THE NEXT
COUPLE OF DAYS.  AS THIS POTENT SYSTEM INTERACTS WITH THE MOIST AND
UNSTABLE AIRMASS OVER TEXAS...SHOWERS AND THUNDERSTORMS WILL RESULT.
AT 600 PM THE SHOWERS AND THUNDERSTORMS WERE DEVELOPING ALONG A LINE
FROM NEAR JASPER TO CROCKETT TO AUSTIN.  AS AN UPPER LEVEL DISTURBANCE
ROTATING AROUND THE UPPER LOW MOVES OVER THE REGION LATER THIS
EVENING...THE STORMS MAY ORGANIZE INTO A SQUALL LINE AND MOVE
SOUTHEASTWARD ACROSS THE NORTHERN PORTIONS OF SOUTHEAST TEXAS TOWARD
MIDNIGHT.  IF THIS OCCURS A REPEAT PERFORMANCE FROM LAST NIGHT WILL
THEN BE POSSIBLE...WITH THUNDERSTORMS MOVING INTO THE COASTAL AREAS
OVERNIGHT.

THE MAIN SEVERE WEATHER THREATS ARE LARGE HAIL AND STRONG DAMAGING
WINDS.  HEAVY RAINFALL IS ALSO POSSIBLE THROUGH TUESDAY MORNING.
AVERAGE RAINFALL AMOUNTS OF 3/4 TO 1.5 INCHES ARE EXPECTED WITH
ISOLATED TOTALS APPROACHING 4 INCHES POSSIBLE.

THE EVOLUTION OF SHOWER AND THUNDERSTORM DEVELOPMENT TONIGHT WILL
DICTATE WHERE THE GREATEST SEVERE WEATHER AND HEAVY RAINFALL THREAT
WILL OCCUR.  RESIDENTS ACROSS SOUTHEAST TEXAS SHOULD BE PREPARED FOR
POSSIBLE SEVERE WEATHER TONIGHT AND TUESDAY MORNING.  EMERGENCY
MANAGERS AND SKYWARN SPOTTERS SHOULD BE PREPARED FOR POSSIBLE
ACTIVATION.

STAY TUNED TO NOAA WEATHER RADIO OR OTHER RELIABLE WEATHER NEWS
SOURCES FOR FURTHER UPDATES.