Alert archive / Texas / Flash Flood Warnings in 1998

Flash Flood Warning 49, NWS Houston/Galveston, TX

September 11, 1998Galveston County, Texas

NWS Houston/Galveston, TX issued this flash flood warning at Sep 11, 1998, 4:01 AM CDT for Galveston County, Texas. It was in force for 4 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Sep 11, 1998, 4:01 AM CDT (09:01 UTC)
Expired
Sep 11, 1998, 8:00 AM CDT
In force
4 hr
Issued by
NWS Houston/Galveston, TX
Area
Whole counties

County Galveston County, TX

The radar

The Houston radar (KHGX), 32 km from the middle of the area, began a volume at 09:04 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 00:00Z, 9.0 hours before the alert went out and 180 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Lake Charles Mun, LA at 00:00Z on 1998-09-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 26 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lake Charles Mun, LA at 00:00Z on 1998-09-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 273 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
26 J/kg
Mixed-layer CIN
-67 J/kg
Mixed-layer LCL
452 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
273 m²/s²
0-3 km storm-relative helicity
445 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
TTAA00 KHOU 110901
FFWHOU
TXC167-111300-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
401 AM CDT FRI SEP 11 1998

THE NATIONAL WEATHER SERVICE IN HOUSTON/GALVESTON HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  GALVESTON COUNTY IN SOUTHEASTERN TEXAS

* UNTIL 800 AM CDT

* AT 4 AM... NATIONAL WEATHER SERVICE RADAR INDICATED A BAND OF
 SHOWERS AND THUNDERSTORMS FROM LEAGUE CITY TO TEXAS CITY AND
 OFFSHORE 40 MILES.  ADDITIONAL STORMS LOCATED OFFSHORE
 GALVESTON EXTENDING OFFSHORE BEYOND 100 MILES WILL CONTINUE
 MAKING THEIR WAY INLAND. MOVEMENT OF ALL PRECIPITATION WAS TO THE
 NORTHWEST NEAR 40 MPH.

* MANY PARTS OF THE COUNTY...ESPECIALLY THE EASTERN HALF NEAR
 HIGHWAY 146...HAVE RECEIVED 2 TO 4 INCHES OF RAIN THE PAST 3
 HOURS.  ADDITIONAL RAINFALL WILL FURTHER COMPLICATE FLOODING
 PROBLEMS.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE WATER COVERS THE ROADWAY.
THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS SAFELY.
VEHICLES CAUGHT IN RISING WATER SHOULD BE ABANDONED QUICKLY.  MOVE
TO HIGHER GROUND.

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Houston/Galveston, TX wrote its last area forecast discussion before this flash flood warning went out at Sep 11, 2:32 AM CDT, 1 hour 29 minutes earlier.

Area forecast discussion, Sep 11, 2:32 AM CDT, 1 hour 29 minutes before
SOUTHEAST TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
130 AM CDT FRI SEP 11 1998

THE 1 AM UPDATE FROM TPC (NHC) POSITIONED T.S. FRANCES JUST 30 MILES
NE OF PORT ARANSAS.  THE SFC AND BUOY REPORTS OVER THE PAST FEW
HOURS CONFIRM THAT THE STORM CENTER SHOULD MAKE LANDFALL WITHIN THE
NEXT HOUR OR SO...WITH THE 06Z SURFACE ANALYSIS SHOWING THE CENTER
JUST OFFSHORE AND THE 07Z SURFACE INDICATING THE CENTER JUST
ONSHORE.  THE HEAVIEST RAIN BANDS CONTINUED TO MOVE ONSHORE OVER
SETX AND AM EXPECTING RAIN BANDS TO AFFECT THE FORECAST AREA
THROUGHOUT THE DAY FROM THE GULF.

THE ETA/NGM APPEAR TO BE FORECASTING THE MOVMENT OF THE STORM
WELL...THOUGH NOT THE POSITION OF THE LANDFALL OF THE STORM.  LIKE
THE ETA AS COMPARED TO THE OTHER MODELS...ESPECIALLY SINCE THE AVN
REALLY LINGERS THE STORM OFFSHORE TOO LONG AND THE NGM CURLS THE
STORM CENTER ALMOST DUE SOUTH IN THE LATER PERIODS.  THE STORM LOOKS
TO BE FINALLY CAUGHT UP IN THE CIRCULATION AROUND THE 500 MB HIGH
LOCATED OVER THE CENTRAL PORTON OF THE COUNTRY.  THE ETA FORECASTS
THIS HIGH TO BUILD SOUTH INTO SETX...PUSHING FRANCES WELL WEST OF
THE FORECAST AREA BY LATE TONIGHT.  A STRONG PRESSURE GRADIENT
BETWEEN THE LOW AND THE SURFACE HIGH TO THE NE WILL CONTINUE TO KEEP
EASTERLY WINDS OVER THE COASTAL AREAS THROUGH TONIGHT AND SATURDAY.

THREATS FOR THE FIRST PERIOD INCLUDE HEAVY RAINFALL AND THE RELATED
FLASH FLOOD THREAT...AND POSSIBLE TORNADOES WITH THE RAINBANDS.
WILL KEEP THE FLASH FLOOD WATCH IN EFFECT TODAY.  WILL ALSO NEED A
WIND ADVISORY IN THE COUNTIES OUTSIDE THE TROPICAL STORM WARNING.
THE COASTAL FLOODING THREAT WILL CONTINUE INTO TONIGHT...AS THE
STORM CONTINUES MOVING WELL INLAND AND THE PRESSURE GRADIENT
DECREASES THE TIDES SHOULD SLOWLY SUBSIDE.

AM EXPECTING TEMPERATURES TODAY TO BE A BIT BELOW THE FWC.  IN THE
LATTER PERIODS WILL GO CLOSER TO THE MOS GUIDANCE.  PL/40

PRELIMS...
CLL T/E  E/B 82/75 90/74 9532 1ST PD...WND 20-30 GUSTY/FFA/WND ADV
NE  T/C >B/B 80/75 87/75 9422 1ST PD...WND 20-30 GUSTY/FFA/WND ADV
IAH T/W  E/B 80/76 90/75 9732 1ST PD...WND 20-30G40 /FFA/WND ADV
                              2ND PD...WND 10-20 AND GUSTY
GLS T/W  E/B 82/77 87/79 9753 1ST PD...WND 25-35G45 AND FFA
                              2ND PD...WND 15-25G30

In the hours before

Special weather statement, Sep 11, 3:58 AM CDT, 3 minutes before
TXZ163-164-176>179-195>200-210>214-226-227-235>238-112030-

SEVERE WEATHER AND HEAVY RAINFALL OUTLOOK FOR SOUTHEAST TEXAS
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
358 AM CDT FRI SEP 11 1998

...TROPICAL STORM FRANCES WILL PROVIDE HEAVY RAINFALL AND CHANCES
FOR SEVERE WEATHER ACROSS SOUTHEAST TEXAS TODAY...

A FLASH FLOOD WATCH IS IN EFFECT FOR TODAY FOR ALL OF SOUTHEAST
TEXAS AS RAINBANDS ASSOCIATED WITH TROPICAL STORM FRANCES WILL MOVE
OVER THE AREA TODAY.  AS THE TROPICAL STORM CONTINUES TO MOVE
INLAND...THE HEAVIER AMOUNTS OF RAIN IS EXPECTED TO FALL MAINLY
ALONG AND SOUTH OF A LINE FROM LIBERTY TO CONROE TO COLLEGE STATION.
RAINFALL BY THIS EVENING SHOULD AVERAGE 2 TO 4 INCHES...THOUGH IN
THOSE AREAS WHERE RAINBANDS MOVE CONTINUALLY OVER THE SAME LOCATIONS
AMOUNTS MAY BE AS HIGH AS 6 TO 8 INCHES.

A FAVORABLE WIND PROFILE ALOFT INDICATES THAT SOME OF THE STRONGER
STORMS MAY ALSO PRODUCE ISOLATED SEVERE WEATHER TODAY.  THE GREATEST
SEVERE WEATHER THREAT WILL BE ISOLATED TORNADOES AND DAMAGING
STRAIGHT LINE WINDS.

REMEMBER...A FLASH FLOOD WATCH MEANS THE THREAT OF FLASH FLOODING
EXISTS WITHIN THE WATCH AREA.  PEOPLE IN THE WATCH AREA SHOULD
MONITOR WEATHER CONDITIONS CLOSELY.  BE READY TO MOVE TO HIGHER
GROUND IF FLOODING IS OBSERVED OR A WARNING IS ISSUED.

IF SEVERE WEATHER IS OBSERVED...CONTACT YOUR LOCAL LAW ENFORCEMENT
AGENCY AND ASK THEM TO RELAY YOUR INFORMATION TO THE NATIONAL
WEATHER SERVICE.

STAY TUNED TO NOAA WEATHER RADIO OR YOUR LOCAL RADIO OR TV STATION
FOR THE LATEST WEATHER INFORMATION.
Special weather statement, Sep 11, 3:58 AM CDT, 3 minutes before
TXZ163-164-176>179-195>200-210>214-226-227-235>238-112030-

SEVERE WEATHER AND HEAVY RAINFALL OUTLOOK FOR SOUTHEAST TEXAS
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
358 AM CDT FRI SEP 11 1998

...TROPICAL STORM FRANCES WILL PROVIDE HEAVY RAINFALL AND CHANCES
FOR SEVERE WEATHER ACROSS SOUTHEAST TEXAS TODAY...

A FLASH FLOOD WATCH IS IN EFFECT FOR TODAY FOR ALL OF SOUTHEAST
TEXAS AS RAINBANDS ASSOCIATED WITH TROPICAL STORM FRANCES WILL MOVE
OVER THE AREA TODAY.  AS THE TROPICAL STORM CONTINUES TO MOVE
INLAND...THE HEAVIER AMOUNTS OF RAIN IS EXPECTED TO FALL MAINLY
ALONG AND SOUTH OF A LINE FROM LIBERTY TO CONROE TO COLLEGE STATION.
RAINFALL BY THIS EVENING SHOULD AVERAGE 2 TO 4 INCHES...THOUGH IN
THOSE AREAS WHERE RAINBANDS MOVE CONTINUALLY OVER THE SAME LOCATIONS
AMOUNTS MAY BE AS HIGH AS 6 TO 8 INCHES.

A FAVORABLE WIND PROFILE ALOFT INDICATES THAT SOME OF THE STRONGER
STORMS MAY ALSO PRODUCE ISOLATED SEVERE WEATHER TODAY.  THE GREATEST
SEVERE WEATHER THREAT WILL BE ISOLATED TORNADOES AND DAMAGING
STRAIGHT LINE WINDS.

REMEMBER...A FLASH FLOOD WATCH MEANS THE THREAT OF FLASH FLOODING
EXISTS WITHIN THE WATCH AREA.  PEOPLE IN THE WATCH AREA SHOULD
MONITOR WEATHER CONDITIONS CLOSELY.  BE READY TO MOVE TO HIGHER
GROUND IF FLOODING IS OBSERVED OR A WARNING IS ISSUED.

IF SEVERE WEATHER IS OBSERVED...CONTACT YOUR LOCAL LAW ENFORCEMENT
AGENCY AND ASK THEM TO RELAY YOUR INFORMATION TO THE NATIONAL
WEATHER SERVICE.

STAY TUNED TO NOAA WEATHER RADIO OR YOUR LOCAL RADIO OR TV STATION
FOR THE LATEST WEATHER INFORMATION.

The office that day

Everything else NWS Houston/Galveston, TX issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 10, 7:13 PM CDTFlash Flood WarningHGXGalveston4 hr
Sep 10, 8:02 PM CDTTornado WarningHGXBrazoria, Galveston63 min
Sep 10, 10:09 PM CDTFlash Flood WarningHGXBrazoria, Matagorda, Wharton4 hr
Sep 10, 10:09 PM CDTFlash Flood WarningHGXFort Bend4 hr
Sep 11, 12:09 AM CDTFlash Flood WarningHGXGalveston4 hr
Sep 11, 1:29 AM CDTTornado WarningHGXGalveston, Harris66 min
Sep 11, 2:03 AM CDTFlash Flood WarningHGXBrazoria, Fort Bend, Harris4 hr
Sep 11, 3:31 AM CDTTornado WarningHGXGalveston64 min
Sep 11, 4:31 AM CDTTornado WarningHGXHarris64 min
Sep 11, 4:39 AM CDTFlash Flood WarningHGXJackson4 hr
Sep 11, 5:32 AM CDTFlash Flood WarningHGXGrimes, Montgomery, Waller4 hr
Sep 11, 5:54 AM CDTFlash Flood WarningHGXHarris4 hr
Sep 11, 6:06 AM CDTTornado WarningHGXFort Bend64 min
Sep 11, 6:18 AM CDTTornado WarningHGXHarris62 min
Sep 11, 7:49 AM CDTFlash Flood WarningHGXBrazoria, Galveston4 hr
Sep 11, 7:49 AM CDTFlash Flood WarningHGXFort Bend4 hr
Sep 11, 8:58 AM CDTFlash Flood WarningHGXHarris6 hr

Nearby

Flash Flood Warnings in Texas, 1998Every flash flood warning in 1998

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.