Alert archive / Texas / Flash Flood Warnings in 1997

Flash Flood Warning 44, NWS Houston/Galveston, TX

May 21, 1997Austin County, Harris County, Waller County, Texas

NWS Houston/Galveston, TX issued this flash flood warning at May 21, 1997, 9:33 PM CDT for Austin County, Harris County, Waller County, Texas. It was in force for 117 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
May 21, 1997, 9:33 PM CDT (02:33 UTC)
Expired
May 21, 1997, 11:30 PM CDT
In force
117 min
Issued by
NWS Houston/Galveston, TX
Area
Whole counties

Counties Austin County, TX, Harris County, TX, Waller County, TX

The radar

The Houston radar (KHGX), 92 km from the middle of the area, began a volume at 02:35 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, 2.6 hours before the alert went out and 260 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 1997-05-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1896 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 1997-05-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 56 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
1896 J/kg
Mixed-layer CIN
-6 J/kg
Mixed-layer LCL
745 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
56 m²/s²
0-3 km storm-relative helicity
71 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.8

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KHOU 220232
FFWHOU
TXC015-201-473-220430-
 
BULLETIN - EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
933 PM CDT WED MAY 21 1997
 
THE NATIONAL WEATHER SERVICE IN HOUSTON/GALVESTON HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL 1130 PM CDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN SOUTH CENTRAL TEXAS
 
   ...AUSTIN COUNTY
 
IN SOUTHEAST TEXAS
 
   ...WESTERN HARRIS COUNTY...WALLER COUNTY
 
AT 928 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED AN AREA OF
SHOWERS AND THUNDERSTORMS FROM SOUTH AUSTIN COUNTY TO SOUTHERN WALLER
COUNTY TO KATY TO BELLAIRE. THIS AREA OF PRECIPIATION IS MOVING NORTH AT
10 MPH. AUSTIN COUNTY SHERIFF'S DEPARTMENT REPORTED 3 FEET OF WATER ON
THE ROAD AT THE INTERSECTION OF HIGHWAY 36 AND HIGHWAY 90 IN SEALY.
RADAR ESTIMATES OF 6 TO 8 INCHES AND CONFIRMED REPORTS OF OVER 4 AND 1/2
INCHES HAVE REPORTED IN SOUTHWESTERN HARRS COUNTY.  THE DEPARTMENT OF
PUBLIC SAFETY HAS REPORTED STREET FLOODING IN SEALY.
 
AN ADDITIONAL 1 TO 2 INCHES OF RAIN IS POSSIBLE WITH THESE THUNDERSTORMS
OVER THE NEXT SEVERAL HOURS.
 
BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO
RECOGNIZE THE DANGERS OF FLOODS AND FLASH FLOODS. IF F*LASH
FLOODING IS OBSERVED...ACT QUICKLY. MOVE UP TO ESCAPE FLOOD
WATERS. DO NOT STAY IN AREAS SUBJECT TO FLOODING WHEN WATER
BEGINS RISING.
 
 
 
&

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 May 21, 7:42 PM CDT, 1 hour 51 minutes earlier.

Area forecast discussion, May 21, 7:42 PM CDT, 1 hour 51 minutes before
SOUTHEAST TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
740 PM CDT WED MAY 21 1997

00Z CRP SOUNDING SHOWS DRY SPIKE ABOVE 790 MB. NOT SURPRISING THAT
MESOCYCLONE DEVELOPED OVR COLORADO COUNTY. >50 DBZ EXTENDS TO NR 40
KFT FM THIS STORM BESIDES STRONG ROTATION.

OTHERWISE...NOT MUCH HAS CHANGED FM PREV FCST DISCUSSION...HI PWS...
RIGHT READ QUAD OF UPPER LVL JET OVR RGN TONITE...SFC CONFLUENT
FLOW...HI LIS. COLLIDING BOUN.DARIES FM PRESENT CONVECTION MAY BE
ENOUGH TO MAINTAIN CONVECTION FOR SEVERAL HOURS...DESPITE WEAKENING
CAPES AS NIGHT PROGRESSES.

NO CHANGE TO PREV FCST PACKAGE EXCEPT FOR CLL AREA 1ST PD POPS.
RECOMMEND 30 PERCENT.

#37

The office that day

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

IssuedProductOfficeCountiesLasted
May 21, 7:09 PM CDTTornado WarningHGXColorado66 min
May 21, 7:43 PM CDTTornado WarningHGXWharton62 min
May 21, 8:25 PM CDTSevere Thunderstorm WarningHGXAustin50 min

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.