Alert archive / Texas / Flash Flood Warnings in 1999

Flash Flood Warning 21, NWS Austin/San Antonio, TX

May 10, 1999Williamson County, Texas

NWS Austin/San Antonio, TX issued this flash flood warning at May 10, 1999, 2:08 PM CDT for Williamson County, Texas. It was in force for 2 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
May 10, 1999, 2:08 PM CDT (19:08 UTC)
Expired
May 10, 1999, 4:15 PM CDT
In force
2 hr
Issued by
NWS Austin/San Antonio, TX
Area
Whole counties

County Williamson County, TX

The radar

The Ft Hood radar (KGRK), 22 km from the middle of the area, began a volume at 19:10 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

Fort Worth, TX (KFWD), launched 12:00Z, 7.1 hours before the alert went out and 245 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, Fort Worth, TX at 12:00Z on 1999-05-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 8 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, Fort Worth, TX at 12:00Z on 1999-05-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 126 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
8 J/kg
Mixed-layer CIN
-449 J/kg
Mixed-layer LCL
927 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
126 m²/s²
0-3 km storm-relative helicity
276 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 KEWX 101912
FFWSAT
TXC491-102115-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
208 PM CDT MON MAY 10 1999

THE NATIONAL WEATHER SERVICE IN AUSTIN/SAN ANTONIO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  WILLIAMSON COUNTY

* UNTIL 415 PM CDT

* A LINE OF STRONG THUNDERSTORMS MOVING EASTWARD ACROSS WILLIAMSON COUNTY
  WILL PRODUCE AN ADDITIONAL 1 TO 2 INCHES OF RAIN.  STRONG WINDS    
  WITH GUSTS TO NEAR 50 MPH ARE ALSO POSSIBLE WITH THESE STORMS.  

EXCESSIVE RUNOFF FROM THESE STORMS WILL CAUSE FLASH FLOODING OF SMALL
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY
ROADS AND FARMLANDS ALONG THE BANKS OF CREEKS AND STREAMS AND OTHER
LOW LYING AREAS ARE SUBJECT TO FLASH FLOODING.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS OCCURRING OR IS
IMMINENT. MOST FLASH FLOOD DEATHS OCCUR IN AUTOMOBILES. DO NOT
ATTEMPT TO CROSS BRIDGES...DIPS...OR OTHER LOW SPOTS IF WATER COVERS
THE ROADWAY. NEVER TRY TO CROSS A FLOWING STREAM...EVEN A SMALL
ONE...ON FOOT. TO ESCAPE RISING WATER MOVE UP TO HIGHER GROUND.

STAY TUNED TO TV...RADIO...OR NOAA WEATHER RADIO FOR ADDITIONAL 
STATEMENTS.

The office that day

Everything else NWS Austin/San Antonio, TX issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 9, 11:07 PM CDTSevere Thunderstorm WarningEWXEdwards, Val Verde58 min
May 9, 11:58 PM CDTSevere Thunderstorm WarningEWXEdwards62 min
May 10, 12:18 AM CDTTornado WarningEWXEdwards62 min
May 10, 12:25 AM CDTFlash Flood WarningEWXEdwards3 hr
May 10, 12:56 AM CDTSevere Thunderstorm WarningEWXBurnet, Llano59 min
May 10, 1:08 AM CDTSevere Thunderstorm WarningEWXEdwards62 min
May 10, 10:02 AM CDTSevere Thunderstorm WarningEWXWilliamson58 min
May 10, 11:01 AM CDTSevere Thunderstorm WarningEWXWilliamson59 min
May 10, 1:37 PM CDTFlash Flood WarningEWXBurnet, Llano3 hr
May 10, 2:40 PM CDTSevere Thunderstorm WarningEWXTravis, Williamson65 min
May 10, 3:49 PM CDTSevere Thunderstorm WarningEWXLee56 min
May 10, 4:50 PM CDTFlash Flood WarningEWXWilliamson3 hr
May 10, 5:05 PM CDTSevere Thunderstorm WarningEWXTravis, Williamson45 min
May 10, 6:57 PM CDTSevere Thunderstorm WarningEWXCaldwell, Gonzales, Guadalupe48 min

Nearby

Flash Flood Warnings in Texas, 1999Every flash flood warning in 1999

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.