Flash Flood Warning 66, NWS Houston/Galveston, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
215 PM CST WED NOV 17 2004

.DISCUSSION...
SHOWERS AND THUNDERSTORMS...SOME OCCASIONALLY ROTATING...CONTINUE TO
DEVELOP ACROSS SOUTHEAST TEXAS AHEAD OF A SLOW MOVING SQUALL LINE.
THE LINE IS MOVING OUT OF OUR WESTERN COUNTIES AND WILL PROBABLY BE
IN THE HOUSTON METRO AREA JUST IN TIME FOR THE AFTERNOON RUSH HOUR.
BY ZONE ISSUE TIME...WELL BE ABLE TO REMOVE THE NORTHWEST COUNTIES
FROM THE FLOOD WATCH. WILL KEEP THE REMAINING PORTIONS OF SOUTHEAST
TEXAS IN THE FLOOD WATCH. WIDESPREAD ADDITIONAL 1 TO 3 INCH AMOUNTS
WITH ISOLATED 5 INCH TOTALS COULD STILL LEAD TO SOME FLOODING. AS
THE STORMS MOVE TO THE EAST THIS EVENING...WELL LIKELY BE ABLE TO
REMOVE MORE COUNTIES...IF NOT ALL OF THEM...FROM THE WATCH BY
MIDNIGHT. AS FOR SEVERE WEATHER...WE CONTINUE TO WATCH FOR SPINNERS
ALONG AND AHEAD OF THE SQUALL LINE AS LOW LEVEL INFLOW AND UPPER
LEVEL DIFFLUENCE BOTH REMAIN STRONG. EXPECT CONVECTION TO COME TO AN
END OVERNIGHT BUT WE COULD SEE SOME ACTIVITY TOMORROW MORNING NEAR
AND ALONG THE COAST. AFTER A RAIN BREAK THURSDAY AND THURSDAY
NIGHT...WELL GRADUALLY GET BACK INTO A WET PATTERN ON FRIDAY AS A
SOUTHWEST FLOW ALOFT BECOMES ESTABLISHED AGAIN. THIS FLOW WILL
LIKELY KEEP THE NEXT COLD FRONT ON SUNDAY OR MONDAY FROM NOT MAKING
IT ALL THE WAY THROUGH THE AREA. WITH THIS BOUNDARY BECOMING
STATIONARY AND THE NEXT UPPER LOW DROPPING TO THE WEST OF TEXAS...
IMPULSES WILL RIDE ACROSS THE AREA ON THE SOUTHWEST FLOW ALOFT.
THESE HARD TO TIME FEATURES WILL RESULT IN BETTER RAIN CHANCES. FOR
NOW...WILL GO WITH 50% POPS EVERYWHERE FROM SATURDAY ON INTO THE
MIDDLE OF NEXT WEEK. THESE POPS MAY EVENTUALLY NEED TO BE
SIGNIFICANTLY RAISED DEPENDING ON THE STRENGTH AND MOVEMENT OF THE
UPPER LOW AND THE LOCATION OF ANY FRONTAL BOUNDARIES. CONFIDENCE IN
THIS FORECAST PACKAGE IS LOW. ON YEAH...WILL ADD PATCHY FOG TO THE
FORECAST FOR TONIGHT. 42
&&

.MARINE...
WILL KEEP THE SMALL CRAFT ADVISORY UP FOR THE 00-60 NM WATERS
TONIGHT ALTHOUGH GRADIENT SHOULD DRAMATICALLY RELAX OVERNIGHT. WINDS
AND SEAS SHOULD REMAIN BENIGN THURSDAY INTO THE WEEKEND WITH BROAD
LOW STAYING OVER TEXAS AND A WEAKER HIGH FURTHER EAST. MODEL
CONSISTENCY NOT OCCURRING WITH RESPECT TO NEXT STORM EVENT(S) TO COME
OUT OF THE SOUTHWEST SO HAVE LITTLE CONFIDENCE IN DETAILS OF WINDS
AND SEAS BEYOND FRIDAY. 30
&&

.AVIATION...
BROAD BAND OF CONVECTION ASSOCIATED WITH EASTWARD PROGRESSION OF
UPPER TROUGH WILL MOVE THROUGH HUB AIRPORTS 22-01Z TIME FRAME.
EXPECT AT LEAST SOME CLEARING LATE TONIGHT AND WITH WET GROUND AND
NEAR CALM WINDS...IFR FOG ALL BUT GLS BY 10Z AND CONTINUING INTO THE
MID MORNING AT LEAST. 30
&&

.HGX WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH ALL BUT NW PORTIONS OF SOUTHEAST TEXAS UNTIL MIDNIGHT.
SCA 00 TO 60 NM WATERS.
SCEC BAYS.
&&

.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 61 74 59 74 59 / 40 10 10 50 30
HOUSTON (IAH)         64 76 61 76 60 / 70 10 10 30 30
GALVESTON (GLS)       75 67 76 65 76 / 80 20 10 30 30
&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1039 AM CST WED NOV 17 2004

TXZ163-164-176>179-195>200-210>214-226-227-235>238-181300-
AUSTIN-BRAZORIA-BRAZOS-BURLESON-CHAMBERS-COLORADO-FORT BEND-GALVESTON-
GRIMES-HARRIS-HOUSTON-JACKSON-LIBERTY-MADISON-MATAGORDA-MONTGOMERY-
POLK-SAN JACINTO-TRINITY-WALKER-WALLER-WASHINGTON-WHARTON-
1039 AM CST WED NOV 17 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST TEXAS.

...A FLOOD WATCH IS IN EFFECT FOR ALL OF SOUTHEAST TEXAS THROUGH
MIDNIGHT TONIGHT...

.DAY ONE...REMAINDER OF TODAY AND TONIGHT.
THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS TODAY ACROSS
SOUTHEAST TEXAS. UPPER LEVEL LOW PRESSURE WILL MOVE ACROSS CENTRAL
AND NORTHERN TEXAS TODAY. MODERATE TO STRONG WIND SHEAR...OR TURNING
OF WINDS WITH HEIGHT...ALONG WITH ABUNDANT MOISTURE AND HIGH
INSTABILITIES WILL RESULT IN THE THREAT FOR SEVERE THUNDERSTORMS
ACROSS MUCH OF SOUTHEAST TEXAS THIS MORNING AND THIS AFTERNOON. THE
MAIN SEVERE WEATHER THREAT WILL BE STRONG DAMAGING WINDS AND
ISOLATED TORNADOES. LARGE HAIL IS ALSO POSSIBLE WITH THESE SEVERE
THUNDERSTORMS.

IN ADDITION TO THE SEVERE WEATHER THREAT...SHOWERS AND THUNDERSTORMS
WILL PRODUCE AN ADDITIONAL 1 TO 3 INCHES OF RAIN ACROSS MUCH OF
SOUTHEAST TEXAS. ISOLATED 5 INCH TOTALS ARE VERY POSSIBLE WHERE
TRAINING OF THUNDERSTORMS OCCURS. THESE RAINFALL TOTALS IN
COMBINATION WITH SOME PREVIOUS HEAVY RAINFALL COULD LEAD TO FLOODING.

SOME MINOR COASTAL FLOODING ALONG THE WESTERN SHORE OF GALVESTON BAY
AND THE NORTHERN FACING SHORES OF GALVESTON ISLAND AND THE BOLIVAR
PENINSULA IS POSSIBLE DUE TO THE COMBINATION OF HEAVY RAINFALL AND
ABOVE NORMAL TIDE LEVELS.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY...
HAZARDOUS WEATHER IS NOT ANTICIPATED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS POSSIBLE TODAY AND TONIGHT.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
449 PM CST WED NOV 17 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

0937 AM     TORNADO          LA PORTE                29.67N 95.04W
11/17/2004  F0               HARRIS             TX   EMERGENCY MNGR

            MINOR ROOF DAMAGE WITH FENCES DOWN IN RESIDENTIAL AREAS.
            WINDOW BLOWN OUT WITH SIDING DAMAGE TO HOME. DAMAGE
            REPORTED NEAR DRIFTWOOD AND FAIRMONT STREETS.

1015 AM     TORNADO          3 WSW CROSBY            29.90N 95.10W
11/17/2004  F0               HARRIS             TX   EMERGENCY MNGR

            POWERLINES DOWN ON SHELDON ROAD AND OLD HIGHWAY 90. KEY
            MAP 418 X.

0325 PM     TSTM WND DMG     TOMBALL                 30.10N 95.62W
11/17/2004                   HARRIS             TX   TRAINED SPOTTER

            ROOF AND TREE DAMAGE TO TOMBALL JUNIOR HIGH SCHOOL.

&&

GH / PB