Tornado Warning 18, NWS Houston/Galveston, TX

SOUTHEAST TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
255 PM CDT THU SEP 19 1996

S/W RAPIDLY HEADED TOWARDS THE AREA ALONG WITH THE SLOWER LINE OF
THUNDERSTORMS IN NC/C TEX.  TAIL END OF THE THUNDERSTORMS IS SLOWING
DOWN IN RESPONSE TO APPROACHING S/W BUT AFTER IT CATCHES UP IT WILL
COME PLOWING THROUGH THE AREA THIS EVENING!  BRINGING A STRONG
FOCUSING MECHANISM FOR LOCALLY HEAVY RAIN AND POSSIBLY SEVERE
WX...THETAE LAPSE RATES OF 25 TO 40 DEG...LI-9 AND SOME TURNING IN
THE LOWEST 3KFT.  DAMAGING WINDS THE BIGGEST THREAT AND PERHAPS HAIL.
IF THE ONGOING AREA OF STORMS WELL TO THE NORTH SHOULD LAYS DOWN A
DEEP ENOUGH OUTFLOW BOUNDARY THAT MAKES IT PAST HUNTSVILLE THEN THE
THREAT FOR TORNADOES MAY BE A CONCERN TONIGHT DUE THE STRENGTHENED LL
FLOW AHEAD OF IT. CRP OBS CONTINUES TO SHOW GUSTY S WINDS AND UPPER
70 DWPTS.  WILL REISSUE R+/SVR OUTLOOK BEFORE 430 PM TO HIGHLIGHT
UPCOMING WX. PREV HEAVY RAINS OF 3 TO 4.7 INCHES S OF I-10/AND EAST
OF KATY AND IN A CORRIDOR BACK TO THE NW HAVE COMPLICATED THE
SITUATION FOR TONIGHT MAKING THE THREAT FOR FLASH FLOODING GREATER.
WILL HOLD OFF ON FFA FOR THE AREA BUT WILL ADVISE NEXT SHIFT TO
MONITOR CLOSELY.  UPPER LEVEL IMPULSE SHOULD HAVE MOVED THROUGH THE
AREA BY 3 AM AND A SECOND TO APPROACH ON FRIDAY...BUT CONVECTION
TONIGHT MAY SCOUR/ALTER THE REGIME DRAMATICALLY.  PREV RUNS INDICATED
FROPA BUT WITH NEW RUN IT LOOKS AS THOUGH IT WILL HANG UP TO THE
NW...RIDGE BEHIND IT HAS WEAKENED...SO DO NOT ANTICIPATE IT MAKING
THIS FAR SE.

WILL UP POPS FOR TONIGHT...LOCALLY HEAVY RAIN AND SOME SEVERE.

45

CLL...75/91/72/92 743
IAH...76/90/75/90 754
GLS...80/87/80/88 645

TXZ163-164-176>179-195>200-210>214-226-227-235>238-200900-

SEVERE WEATHER AND HEAVY RAINFALL OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON TX
350 PM CDT THU SEP 19 1996

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS AND LOCALLY HEAVY RAIN
TONIGHT THROUGH FRIDAY.

AN UPPER LEVEL DISTURBANCE MOVING ACROSS NORTHERN MEXICO INTO
SOUTHERN TEXAS WILL COMBINE WITH A VERY MOIST AND UNSTABLE ATMOSPHERE
TO PRODUCE SCATTERED TO NUMEROUS THUNDERSTORMS SOME OF WHICH MAY
BECOME SEVERE.  IN ADDITION LOCALLY HEAVY RAINS WILL BE POSSIBLE WITH
THE STORNGER STORMS...RAINFALL ACCUMULATIONS OF AROUND 1/4 TO 1/2
INCH WITH ISOLATED AMOUNTS TO AROUND 3 INCHES.

THE GREATEST THREAT OF SEVERE WEATHER WILL BE DAMAGING WINDS AND
LARGE HAIL...ISOLATED TORNADOES WILL ALSO BE POSSIBLE.

MARINE INTERESTS ALONG THE UPPER TEXAS COAST SHOULD ANTICIPATE A LINE
OF STRONG THUNDERSTORMS TO MOVE INTO THE COASTAL WATERS TONIGHT AFTER
MIDNIGHT.

EMERGENCY MANAGEMENT OFFICIALS AND STORM SPOTTERS SHOULD BE PREPARED
FOR ACTIVATION LATER TONIGHT.

STAY TUNED TO NOAA WEATHER RADIO OR OTHER NEWS SOURCES FOR FURTHER
STATEMENTS...WATCHES...OR WARNINGS.