Alert archive / Texas / Flash Flood Warnings in 2008

Flash Flood Warning 8, NWS Austin/San Antonio, TX

May 21, 2008Frio County, Medina County, Texas

NWS Austin/San Antonio, TX issued this flash flood warning at May 21, 2008, 8:52 PM CDT for Frio County, Medina 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 outline as issued.

The facts

Issued
May 21, 2008, 8:52 PM CDT (01:52 UTC)
Expired
May 21, 2008, 11:45 PM CDT
In force
3 hr
Issued by
NWS Austin/San Antonio, TX
Area
Storm-based polygon
Flood severity
None

Counties Frio County, TX, Medina County, TX

The radar

The Laughlin AFB radar (KDFX), 113 km from the middle of the area, began a volume at 01:54 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

Del Rio, TX (KDRT), launched 00:00Z, 1.9 hours before the alert went out and 168 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, Del Rio, TX at 00:00Z on 2008-05-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 869 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Del Rio, TX at 00:00Z on 2008-05-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -8 square meters per square second.1939Sfc1 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
869 J/kg
Mixed-layer CIN
-138 J/kg
Mixed-layer LCL
3018 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
-8 m²/s²
0-3 km storm-relative helicity
76 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 
WGUS54 KEWX 220152
FFWEWX
TXC163-325-220445-
/O.NEW.KEWX.FF.W.0008.080522T0152Z-080522T0445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
852 PM CDT WED MAY 21 2008

THE NATIONAL WEATHER SERVICE IN AUSTIN SAN ANTONIO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  FRIO COUNTY...
  MEDINA COUNTY...

* UNTIL 1145 PM CDT.

* AT 848 PM CDT...THE NATIONAL WEATHER SERVICE HAS DETERMINED THAT
  RAINFALL ESTIMATES FROM DOPPLER RADAR INDICATE FLASH FLOODING FROM 
  THUNDERSTORMS OVER THE WARNED AREA. 

* LOCATIONS IN THE WARNING AREA INCLUDE BIRY...BADER...QUIHI...NEW
  FOUNTAIN...DUNLAY...GOLDFINCH...PEARSALL...MOORE AND DEVINE.

IT IS HARD TO RECOGNIZE THE DANGERS OF FLOODING AT NIGHT. IF FLOOD
WATERS RISE ACT QUICKLY. DO NOT STAY IN FLOOD PRONE AREAS.

LAT...LON 2961 9899 2865 9882 2864 9941 2962 9937
TIME...MOT...LOC 0152Z 268DEG 0KT 2943 9913 2868 9911

$$
2 follow-up statements
000 
WGUS74 KEWX 220231
FFSEWX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
927 PM CDT WED MAY 21 2008

TXC163-325-220445-
/O.CON.KEWX.FF.W.0008.000000T0000Z-080522T0445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MEDINA TX-FRIO TX-
927 PM CDT WED MAY 21 2008

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1145 PM CDT FOR FRIO
AND MEDINA COUNTIES...

AT 918 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS CONTINUED TO 
DETECT THUNDERSTORMS PRODUCING VERY HEAVY RAIN OVER PORTIONS OF FRIO 
AND MEDINA COUNTIES. RAINFALL AMOUNTS IN EXCESS OF THREE INCHES ARE 
POSSIBLE BETWEEN DERBY AND HONDO AND WILL LIKELY CAUSE THE FLOODING 
OF LOW WATER CROSSINGS ALONG SECONDARY ROADS. 

IT IS HARD TO RECOGNIZE THE DANGERS OF FLOODING AT NIGHT. IF FLOOD 
WATERS RISE ACT QUICKLY. DO NOT STAY IN FLOOD PRONE AREAS. TURN 
AROUND DONT DROWN

LAT...LON 2961 9899 2865 9882 2864 9941 2962 9937
TIME...MOT...LOC 0227Z 180DEG 0KT 2943 9913 2868 9911

$$
000 
WGUS74 KEWX 220407
FFSEWX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1103 PM CDT WED MAY 21 2008

TXC163-325-220445-
/O.CON.KEWX.FF.W.0008.000000T0000Z-080522T0445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MEDINA TX-FRIO TX-
1103 PM CDT WED MAY 21 2008

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1145 PM CDT FOR FRIO
AND MEDINA COUNTIES...

AT 1054 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED 
THAT THUNDERSTORMS WERE MOVING EAST OUT OF THE WARNED AREA...BUT 
FLASH FLOODING DUE TO RUNOFF WAS LIKELY PERSISTING. 

LOW WATER CROSSINGS ALONG FARM TO MARKET ROADS BETWEEN 
PEARSALL....HONDO AND CASTROVILLE WILL LIKELY BE FLOODED AND 
DANGEROUS. DO NOT DRIVE WHERE WATER COVERS THE ROAD. EVEN SUVS AND 
PICKUPS WILL BE SWEPT AWAY BY AS LITTLE AS TWO FEET OF RUSHING 
WATER. TURN AROUND DONT DROWN.

LAT...LON 2961 9899 2865 9882 2864 9941 2962 9937
TIME...MOT...LOC 0403Z 180DEG 0KT 2943 9913 2868 9911

$$

The office that day

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

IssuedProductOfficeCountiesLasted
May 21, 7:25 PM CDTSevere Thunderstorm WarningEWXFrio50 min
May 21, 7:40 PM CDTAreal Flood AdvisoryEWXDimmit, Frio, Zavala2 hr
May 21, 8:31 PM CDTSevere Thunderstorm WarningEWXDimmit, Frio, Zavala17 min
May 21, 10:09 PM CDTSevere Thunderstorm WarningEWXMedina51 min
May 21, 11:11 PM CDTAreal Flood AdvisoryEWXBexar2 hr
May 22, 3:17 AM CDTAreal Flood AdvisoryEWXBexar, Guadalupe, Wilson118 min

Nearby

Flash Flood Warnings in Texas, 2008Every flash flood warning in 2008

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.