Alert archive / Texas / Flash Flood Warnings in 2021

Flash Flood Warning 36, NWS Austin/San Antonio, TX

July 5, 2021Bexar County, Texas

NWS Austin/San Antonio, TX issued this flash flood warning at Jul 5, 2021, 5:54 PM CDT for Bexar 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: Jul 5, 2021, 5:54 PM CDT (22:54 UTC)
Expired: Jul 5, 2021, 9:00 PM CDT
In force: 3 hr
Issued by: NWS Austin/San Antonio, TX
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Bexar County, TX

The radar

The Austin/San Antonio radar (KEWX), 50 km from the middle of the area, began a volume at 22:56 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 12:00Z, 10.9 hours before the alert went out and 225 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: 1872 J/kg
Mixed-layer CIN: -67 J/kg
Mixed-layer LCL: 643 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 44 m²/s²
0-3 km storm-relative helicity: 94 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.4

Open this sounding in Storm Lab

The text

As transmitted.

663 
WGUS54 KEWX 052254
FFWEWX
TXC029-060200-
/O.NEW.KEWX.FF.W.0036.210705T2254Z-210706T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Austin/San Antonio TX
554 PM CDT Mon Jul 5 2021

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

* Flash Flood Warning for...
  Northwestern Bexar County in south central Texas...

* Until 900 PM CDT.

* At 554 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 3 inches of rain 
  have fallen. Additional rainfall amounts of 1 to 2 inches are 
  possible in the warned area. Flash flooding is ongoing or expected 
  to begin shortly.

  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...
  San Antonio, Selma, Helotes, Fair Oaks Ranch, Bulverde, Shavano 
  Park, Hollywood Park, Cross Mountain, The Dominion, Leon Springs, 
  Timberwood Park, Government Canyon State Natural Area, Hill 
  Country Village, Grey Forest, Fiesta Texas, Scenic Oaks and San 
  Geronimo.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 2947 9880 2948 9881 2969 9881 2972 9878
      2972 9874 2975 9865 2974 9861 2976 9855
      2974 9853 2974 9845 2972 9843 2974 9842
      2975 9840 2971 9837 2970 9838 2966 9838
      2965 9834 2962 9835 2960 9831

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

$$

YB

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 5, 8:37 AM CDT	Areal Flood Advisory	EWX	Edwards, Kerr, Real	3 hr
Jul 5, 12:59 PM CDT	Areal Flood Advisory	EWX	Edwards	3 hr
Jul 5, 1:57 PM CDT	Special Weather Statement	EWX	Kinney	63 min
Jul 5, 2:13 PM CDT	Special Weather Statement	EWX	Val Verde	47 min
Jul 5, 2:22 PM CDT	Areal Flood Advisory	EWX	Edwards, Val Verde	3 hr
Jul 5, 2:58 PM CDT	Areal Flood Advisory	EWX	Travis	3 hr
Jul 5, 3:54 PM CDT	Areal Flood Advisory	EWX	Blanco, Comal, Hays	3 hr
Jul 5, 4:02 PM CDT	Areal Flood Advisory	EWX	Comal, Guadalupe	3 hr
Jul 5, 4:06 PM CDT	Areal Flood Advisory	EWX	Val Verde	3 hr
Jul 5, 4:31 PM CDT	Areal Flood Advisory	EWX	Gillespie, Kerr	3 hr
Jul 5, 4:52 PM CDT	Special Weather Statement	EWX	Kinney	53 min
Jul 5, 5:02 PM CDT	Areal Flood Advisory	EWX	Bandera, Bexar, Comal, Kendall	3 hr
Jul 5, 5:16 PM CDT	Flash Flood Warning Considerable damage threat	EWX	Gillespie, Kerr	3 hr
Jul 5, 6:16 PM CDT	Areal Flood Advisory	EWX	Bandera, Bexar, Medina	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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.