Alert archive / Texas / Flash Flood Warnings in 2020

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

September 9, 2020Val Verde County, Texas

NWS Austin/San Antonio, TX issued this flash flood warning at Sep 9, 2020, 4:08 AM CDT for Val Verde 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: Sep 9, 2020, 4:08 AM CDT (09:08 UTC)
Expired: Sep 9, 2020, 7:00 AM CDT
In force: 3 hr
Issued by: NWS Austin/San Antonio, TX
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Val Verde County, TX

The nearest sounding before it

Del Rio, TX (KDRT), launched 00:00Z, 9.1 hours before the alert went out and 105 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: 1077 J/kg
Mixed-layer CIN: -34 J/kg
Mixed-layer LCL: 1412 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: 15 m²/s²
0-3 km storm-relative helicity: 116 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

913 
WGUS54 KEWX 090908
FFWEWX
TXC465-091200-
/O.NEW.KEWX.FF.W.0021.200909T0908Z-200909T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Austin/San Antonio TX
408 AM CDT Wed Sep 9 2020

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

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

* Until 700 AM CDT.

* At 408 AM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 3 inches of rain 
  have fallen. Flash flooding is ongoing or expected to begin 
  shortly.

Excessive rainfall over the burn scar will result in debris flow 
moving into the Pecos River. The debris flow can consist of rock, 
mud, vegetation and other loose materials.

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

  SOURCE...Doppler radar.

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

* Some locations that will experience flash flooding include...
  mainly rural areas of North Central Val Verde County

This includes the following streams and drainages...
  Johnson Draw, Devils Draw and Pecos River.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move away from recently burned areas. Life-threatening flooding of 
creeks, roads and normally dry creeks is likely. The heavy rains 
will likely trigger rockslides, mudslides, and debris flows in steep 
terrain, especially in and around these areas.

Excessive runoff from heavy rainfall will cause flooding of small 
creeks and streams, country roads, farmland, and other low lying 
spots.

&&

LAT...LON 3028 10150 3029 10131 3029 10125 3029 10124
      2991 10128 3005 10151

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
Sep 9, 12:01 AM CDT	Areal Flood Advisory	EWX	Bandera, Edwards, Kendall, Kerr, Kinney, Medina and 3 more	6 hr
Sep 9, 2:50 AM CDT	Areal Flood Advisory	EWX	Bandera, Bexar, Gillespie, Kendall, Medina	3 hr
Sep 9, 3:44 AM CDT	Flash Flood Warning Considerable damage threat	EWX	Bexar, Comal, Kendall	2 hr
Sep 9, 3:53 AM CDT	Flash Flood Watch	EWX	Bandera, Bexar, Blanco, Burnet, Comal, Edwards and 12 more	33 hr
Sep 9, 4:29 AM CDT	Areal Flood Advisory	EWX	Blanco, Burnet, Comal, Hays, Kendall, Llano and 1 more	4 hr
Sep 9, 4:43 AM CDT	Flash Flood Warning Considerable damage threat	EWX	Blanco, Comal, Gillespie, Kendall	5 hr
Sep 9, 6:24 AM CDT	Areal Flood Advisory	EWX	Bexar, Comal, Kendall	3 hr
Sep 9, 7:06 AM CDT	Flash Flood Warning Considerable damage threat	EWX	Burnet, Llano	3 hr
Sep 9, 7:15 AM CDT	Areal Flood Advisory	EWX	Bastrop, Caldwell, Gonzales, Guadalupe, Hays, Lee and 3 more	3 hr
Sep 9, 7:45 AM CDT	Flash Flood Warning Considerable damage threat	EWX	Bastrop, Blanco, Burnet, Caldwell, Comal, Guadalupe and 3 more	4 hr
Sep 9, 7:56 AM CDT	Flash Flood Warning Considerable damage threat	EWX	Edwards, Val Verde	3 hr
Sep 9, 10:00 AM CDT	Flash Flood Warning Considerable damage threat	EWX	Gillespie	3 hr
Sep 9, 10:58 AM CDT	Flash Flood Warning Considerable damage threat	EWX	Edwards	3 hr
Sep 9, 11:51 AM CDT	Areal Flood Advisory	EWX	Edwards, Kerr, Real	3 hr
Sep 9, 1:14 PM CDT	Areal Flood Advisory	EWX	Travis, Williamson	3 hr
Sep 9, 1:38 PM CDT	Areal Flood Advisory	EWX	Bexar, Caldwell, Comal, Guadalupe, Hays, Travis	3 hr
Sep 9, 2:23 PM CDT	Flash Flood Warning Considerable damage threat	EWX	Burnet, Hays, Travis, Williamson	3 hr
Sep 9, 5:22 PM CDT	Areal Flood Advisory	EWX	Travis	3 hr

Nearby

Flash Flood Warnings in Texas, 2020 Every flash flood warning in 2020

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.