Alert archive / Texas / Flash Flood Warnings in 1997

Flash Flood Warning 88, NWS Houston/Galveston, TX

December 20, 1997Harris County, Texas

NWS Houston/Galveston, TX issued this flash flood warning at Dec 20, 1997, 7:07 PM CST for Harris County, Texas. It was in force for 3 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
Dec 20, 1997, 7:07 PM CST (01:07 UTC)
Expired
Dec 20, 1997, 10:15 PM CST
In force
3 hr
Issued by
NWS Houston/Galveston, TX
Area
Whole counties

County Harris County, TX

The radar

The Houston radar (KHGX), 52 km from the middle of the area, began a volume at 01:09 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, 1.1 hours before the alert went out and 213 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 1997-12-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 1997-12-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 325 square meters per square second.1939587897117136Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
496 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
325 m²/s²
0-3 km storm-relative helicity
420 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 210110
FFWHOU
TXC201-210415-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
707 PM CST SAT DEC 20 1997

THE NATIONAL WEATHER SERVICE IN HOUSTON/GALVESTON TX HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL 1015 PM CST
FOR PEOPLE IN THE FOLLOWING LOCATION...

IN SOUTHEASTERN TEXAS

   ...HARRIS COUNTY

AT 705 PM...WEATHER RADAR INDICATES IN EXCESS OF 3 INCHES OF
RAIN HAS FALLEN BETWEEN CYPRESS AND KATY.  WIDESPREAD SHOWERS AND
THUNDERSTORMS ACROSS HARRIS COUNTY WILL LIKELY PRODUCE AN ADDITIONAL
1 TO 2 INCHES OF RAIN WITHIN THE NEXT FEW HOURS.

MOST DEATHS IN FLASH FLOODING OCCUR IN AUTOMOBILES. DO NOT ATTEMPT
TO CROSS BRIDGES...DIPS...OR LOW SPOTS IF WATER COVERS THE ROADWAY.
NEVER TRY TO CROSS A FLOWING STREAM...EVEN A SMALL ONE...ON FOOT.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT
IS HARDER TO RECOGNIZE THE DANGERS OF FLASH FLOODING.

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 Dec 20, 2:40 PM CST, 4 hours 27 minutes earlier.

Area forecast discussion, Dec 20, 2:40 PM CST, 4 hours 27 minutes before
SOUTHEAST TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
240 PM CST SAT DEC 20 1997

EVOLUTION OF ADVERTISED WX EVENT A BIT SLOWER THAN EARLIER THINKING,
BUT INGREDIENTS ARE COMING TOGETHER AS INDICATED BY CURRENT KHGX/EWX
RADARS.  N-S LINE OF SH/TSRA BEGINNING TO FORM BETWEEN SAT/AUS ALONG
SOME SORT OF LOW-LVL CONVERGENCE LINE.  CONVECTION NO DOUBT AIDED BY
VERY IMPRESSIVE DIFFLUENCE ALOFT AS INDICATED BY SATELLITE WV LOOPS.
VERTICAL WIND SHEAR PROFILES STILL SUPPORTIVE OF DAMAGING WIND GUSTS
(AND POSSIBLY ISOLATED TORNADOES) WITH INFLOWS/THETA-E RIDGING STILL
SUPPORTIVE OF SOME HEAVY RAIN.  WOULD LIKE TO KEEP CURRENT HEADLINES
INTACT FOR TONIGHT (SVR/FFA) TAPERING POPS A LITTLE FOR SUNDAY (UN-
TIL THE COLD FRONT PUSHES THRU THE FA BY SUNDAY AFTN).  HOWEVER, THE
FRONT IS NOT EXPECTED TO STRAY TOO FAR E AS THE NEXT UPPER LEVEL LOW
BEGINS TO DIG OVER SRN CA/CA BAJA.  WINDS/AMS TO TURN AROUND QUICKLY
(BY MON) WITH THE NEXT BEST SHOT OF PCPN/CONVECTION PROGGED FOR TUE.
IN THE MEANWHILE, WILL CONTINUE WITH HIGH POPS AND NOT STRAY TOO FAR
FROM GUIDANCE FOR TEMPS.  41

PRELIMS..
CLL  T/>T,E E/E  52/61 40/63  72-0
IAH  T/>T,E E/E  55/63 42/65  +3-0
GLS  T/>T,E E/E  59/64 52/64  +3-0

ALL ZONES (PLEASE)...
(1ST PD: SVR TSTMS & FFW)
(2ND PD: TSRA ENDING.  MC/RA)

In the hours before

Special weather statement, Dec 20, 4:14 PM CST, 2 hours 53 minutes before
GMZ330-335-350-355-370-375-TXZ-176>179-195>200-210>214-226-
227-235>238-210400-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
415 PM CST SAT DEC 20 1997

...SEVERE WEATHER POSSIBLE ACROSS SOUTHEAST TEXAS TONIGHT...

THERE IS A SLIGHT RISK FOR SEVERE WEATHER ACROSS ALL OF SOUTHEAST
TEXAS TONIGHT.

A LINE OF STRONG THUNDERSTORMS WAS DEVELOPING OVER THE HILL COUNTRY
THIS AFTERNOON.  THIS LINE WILL BE MOVING SLOWLY INTO SOUTHEAST TEXAS
THIS EVENING.  THE AIRMASS OVER THE REGION REMAINS UNSTABLE AND VERY
MOIST.  AIDED BY POWERFUL JETSTREAM DYNAMICS...FAVORABLE WIND SHEAR
WITH HEIGHT AND DISTURBANCES ROTATING AROUND AN IMPRESSIVE UPPER
LEVEL STORM SYSTEM...SOME OF THE THUNDERSTORMS THAT DO DEVELOP MAY
BECOME SEVERE.  THE MAIN THREAT OF SEVERE WEATHER WILL FROM DAMAGING
DOWNBURST WINDS ALTHOUGH A FEW ISOLATED TORNADOES ARE ALSO POSSIBLE.

MARINE INTERESTS SHOULD ANTICIPATE STRONG THUNDERSTORMS DEVELOPING
AND MOVING NORTHWARD ACROSS THE UPPER TEXAS COASTAL WATERS THIS
EVENING.  THESE STORMS WILL BRING A THREAT OF WATERSPOUTS AND STRONG
GUSTY WINDS.

PERSONS IN THE WATCH AND OUTLOOK AREAS SHOULD REMAIN ALERT TO RAPIDLY
CHANGING WEATHER CONDITIONS AND BE PREPARED TO MOVE TO A SAFE PLACE
IF SEVERE WEATHER IS OBSERVED OR A WARNING IS ISSUED.

SKYWARN SPOTTERS AND EMERGENCY MANAGEMENT OFFICIALS SHOULD BE ALERT
FOR POSSIBLE ACTIVATION EARLY THIS EVENING AS THREATENING WEATHER
BEGINS MOVING INTO THE AREA.

MONITOR YOUR NOAA WEATHER RADIO...LOCAL RADIO OR TELEVISION...OR YOUR
LOCAL CABLE PROVIDER...FOR FURTHER UPDATES OR WARNINGS ON THIS
DEVELOPING WEATHER SITUATION.
Special weather statement, Dec 20, 4:15 PM CST, 2 hours 52 minutes before
GMZ330-335-350-355-370-375-TXZ-176>179-195>200-210>214-226-
227-235>238-210400-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
415 PM CST SAT DEC 20 1997

...SEVERE WEATHER POSSIBLE ACROSS SOUTHEAST TEXAS TONIGHT...

THERE IS A SLIGHT RISK FOR SEVERE WEATHER ACROSS ALL OF SOUTHEAST
TEXAS TONIGHT.

A LINE OF STRONG THUNDERSTORMS WAS DEVELOPING OVER THE HILL COUNTRY
THIS AFTERNOON.  THIS LINE WILL BE MOVING SLOWLY INTO SOUTHEAST TEXAS
THIS EVENING.  THE AIRMASS OVER THE REGION REMAINS UNSTABLE AND VERY
MOIST.  AIDED BY POWERFUL JETSTREAM DYNAMICS...FAVORABLE WIND SHEAR
WITH HEIGHT AND DISTURBANCES ROTATING AROUND AN IMPRESSIVE UPPER
LEVEL STORM SYSTEM...SOME OF THE THUNDERSTORMS THAT DO DEVELOP MAY
BECOME SEVERE.  THE MAIN THREAT OF SEVERE WEATHER WILL FROM DAMAGING
DOWNBURST WINDS ALTHOUGH A FEW ISOLATED TORNADOES ARE ALSO POSSIBLE.

MARINE INTERESTS SHOULD ANTICIPATE STRONG THUNDERSTORMS DEVELOPING
AND MOVING NORTHWARD ACROSS THE UPPER TEXAS COASTAL WATERS THIS
EVENING.  THESE STORMS WILL BRING A THREAT OF WATERSPOUTS AND STRONG
GUSTY WINDS.

PERSONS IN THE WATCH AND OUTLOOK AREAS SHOULD REMAIN ALERT TO RAPIDLY
CHANGING WEATHER CONDITIONS AND BE PREPARED TO MOVE TO A SAFE PLACE
IF SEVERE WEATHER IS OBSERVED OR A WARNING IS ISSUED.

SKYWARN SPOTTERS AND EMERGENCY MANAGEMENT OFFICIALS SHOULD BE ALERT
FOR POSSIBLE ACTIVATION EARLY THIS EVENING AS THREATENING WEATHER
BEGINS MOVING INTO THE AREA.

MONITOR YOUR NOAA WEATHER RADIO...LOCAL RADIO OR TELEVISION...OR YOUR
LOCAL CABLE PROVIDER...FOR FURTHER UPDATES OR WARNINGS ON THIS
DEVELOPING WEATHER SITUATION.

The office that day

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

IssuedProductOfficeCountiesLasted
Dec 20, 6:43 PM CSTSevere Thunderstorm WarningHGXHarris62 min
Dec 20, 8:22 PM CSTTornado WarningHGXLiberty, Montgomery53 min
Dec 20, 8:41 PM CSTFlash Flood WarningHGXLiberty3 hr
Dec 20, 8:53 PM CSTFlash Flood WarningHGXMontgomery, San Jacinto3 hr
Dec 20, 10:15 PM CSTFlash Flood WarningHGXHarris3 hr
Dec 20, 11:32 PM CSTFlash Flood WarningHGXLiberty3 hr

Nearby

Flash Flood Warnings in Texas, 1997Every flash flood warning in 1997

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.