Alert archive / Texas / Flash Flood Warnings in 2021

Flash Flood Warning 48, NWS Austin/San Antonio, TX

August 17, 2021Val Verde County, Texas

NWS Austin/San Antonio, TX issued this flash flood warning at Aug 17, 2021, 4:20 PM CDT for Val Verde County, Texas. It was in force for 4 hr. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Aug 17, 2021, 4:20 PM CDT (21:20 UTC)
Expired: Aug 17, 2021, 8:00 PM CDT
In force: 4 hr
Issued by: NWS Austin/San Antonio, TX
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Val Verde County, TX

The radar

The Laughlin AFB radar (KDFX), 68 km from the middle of the area, began a volume at 21:23 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.

What was reported inside it

Time	Report	Where	Remark
Aug 17, 5:21 PM CDT	FLASH FLOOD	2 Nw Del Rio, TX	STALLED VAN AT MARY LOU DRIVE AND KINGS WAY WITH WATER UP TO THE BOTTOM OF THE DOORS. RELAYED BY A CERTIFIED CONSULTING METEOROLOGIST.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Del Rio, TX (KDRT), launched 12:00Z, 9.3 hours before the alert went out and 13 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1588 J/kg
Mixed-layer CIN: -51 J/kg
Mixed-layer LCL: 890 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: 57 m²/s²
0-3 km storm-relative helicity: 102 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.2

Open this sounding in Storm Lab

The text

As transmitted.

642 
WGUS54 KEWX 172120
FFWEWX
TXC465-180100-
/O.NEW.KEWX.FF.W.0048.210817T2120Z-210818T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Austin/San Antonio TX
420 PM CDT Tue Aug 17 2021

The National Weather Service in Austin/San Antonio has issued a

* Flash Flood Warning for...
  Southeastern Val Verde County in south central Texas...

* Until 800 PM CDT.

* At 420 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain in over the city of Del RIo. Between 1 and 3 inches of 
  rain have fallen. Additional rainfall amounts up to 1 inch are 
  possible in the warned area. Flash flooding is already occurring.

  HAZARD...Life threatening flash flooding. Thunderstorms
           producing flash flooding.

  SOURCE...Radar.

  IMPACT...Life threatening flash flooding of creeks and streams,
           urban areas, highways, streets and underpasses.

* Some locations that will experience flash flooding include...
  Del Rio, Lake View, Long Point, Black Brush Point, Diablo East, 
  Cienegas Terrace, Val Verde Park, Amistad Village, Governors 
  Landing, 277 South Boat Ramp, Lake Ridge Ranch, 277 North 
  Campground and San Pedro Canyon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Remain alert for flooding even in locations not receiving rain. 
Arroyos, streams, and rivers can become raging killer currents in a 
matter of minutes, even from distant rainfall.

&&

LAT...LON 2944 10106 2958 10095 2959 10079 2947 10078
      2936 10084 2933 10093 2933 10094 2934 10094
      2935 10095 2935 10096 2936 10098 2937 10101
      2938 10101 2939 10102 2940 10103 2941 10104
      2942 10104 2943 10104

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

MO

1 follow-up statement

735 
WGUS74 KEWX 172202
FFSEWX

Flash Flood Statement
National Weather Service Austin/San Antonio TX
502 PM CDT Tue Aug 17 2021

TXC465-180100-
/O.CON.KEWX.FF.W.0048.000000T0000Z-210818T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Val Verde TX-
502 PM CDT Tue Aug 17 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 8 PM CDT THIS EVENING 
FOR SOUTHEASTERN VAL VERDE COUNTY...

At 502 PM CDT, Doppler radar indicated thunderstorms producing 
moderate to occasionally heavy rain in over the city of Del RIo. 
Between 2 and 3 inches of rain have fallen. Additional rainfall 
amounts up to 1 inch are possible in the warned area. Flash flooding 
is likely occurring in the city of Del Rio. The heaviest rains have 
shifted southeast of Del Rio, but there is another round of rain 
moving in from the west that could add to the rain totals.

HAZARD...Life threatening flash flooding. Thunderstorms producing
         flash flooding.

SOURCE...Radar.

IMPACT...Life threatening flash flooding of creeks and streams,
         urban areas, highways, streets and underpasses.

Some locations that will experience flash flooding include...
  Del Rio, Lake View, Long Point, Black Brush Point, Diablo East, 
  Cienegas Terrace, Val Verde Park, Amistad Village, Governors 
  Landing, 277 South Boat Ramp, Lake Ridge Ranch, 277 North 
  Campground and San Pedro Canyon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Remain alert for flooding even in locations not receiving rain. 
Arroyos, streams, and rivers can become raging killer currents in a 
matter of minutes, even from distant rainfall.

&&

LAT...LON 2944 10106 2958 10095 2959 10079 2947 10078
      2936 10084 2933 10093 2933 10094 2934 10094
      2935 10095 2935 10096 2936 10098 2937 10101
      2938 10101 2939 10102 2940 10103 2941 10104
      2942 10104 2943 10104

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

MO

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 16, 7:59 PM CDT	Areal Flood Advisory	EWX	Val Verde	3 hr
Aug 17, 2:28 PM CDT	Special Weather Statement	EWX	Val Verde	47 min
Aug 17, 2:52 PM CDT	Special Weather Statement	EWX	Kinney	38 min
Aug 17, 3:25 PM CDT	Areal Flood Advisory	EWX	Val Verde	3 hr
Aug 17, 4:03 PM CDT	Areal Flood Advisory	EWX	Edwards, Real	3 hr

Nearby

Flash Flood Warnings in Texas, 2021 Every flash flood warning in 2021

Sources

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