Alert archive / Texas / Flash Flood Warnings in 2021

Flash Flood Warning 47, NWS Austin/San Antonio, TX

August 15, 2021Travis County, Texas

NWS Austin/San Antonio, TX issued this flash flood warning at Aug 15, 2021, 2:10 PM CDT for Travis County, Texas. It was in force for 3 hr. 2 reports 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 15, 2021, 2:10 PM CDT (19:10 UTC)
Expired: Aug 15, 2021, 5:15 PM CDT
In force: 3 hr
Issued by: NWS Austin/San Antonio, TX
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Travis County, TX

The radar

The Austin/San Antonio radar (KEWX), 64 km from the middle of the area, began a volume at 19:13 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 15, 3:00 PM CDT	HEAVY RAIN 4	1 Nne Austin, TX	SOCIAL MEDIA VIDEO SHOWS THE UT GREGORY GYM INUNDATED DUE TO THE HEAVY DOWNPOURS THAT AFFECTED THE AUSTIN AREA MAINLY FROM 2 TO 3:30 PM THIS AFTERNOON.
Aug 15, 3:11 PM CDT	FLASH FLOOD	1 Ssw West Lake Hills, TX	THERE ARE SEVERAL STREET CLOSURES ACROSS THE AUSTIN AREA INCLUDING PORTIONS OF HOUEKE LN, POSTEN LN, RIVER HILLS RD AND EANES CREEK AT CAMP CRAFT (REPORT COURTESY OF ATXFLOODS).

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

The nearest sounding before it

Corpus Christi, TX (KCRP), launched 12:00Z, 7.2 hours before the alert went out and 286 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: 2772 J/kg
Mixed-layer CIN: -2 J/kg
Mixed-layer LCL: 641 m above ground
0-6 km bulk shear: 6 kt
0-1 km storm-relative helicity: -61 m²/s²
0-3 km storm-relative helicity: -42 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

770 
WGUS54 KEWX 151910
FFWEWX
TXC453-152215-
/O.NEW.KEWX.FF.W.0047.210815T1910Z-210815T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Austin/San Antonio TX
210 PM CDT Sun Aug 15 2021

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

* Flash Flood Warning for...
  Central Travis County in south central Texas...

* Until 515 PM CDT.

* At 210 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 4 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...
  Austin, Tanglewood Forest, Austin Bergstrom Int Airport, Lakeway, 
  Bee Cave, West Lake Hills, Hudson Bend, The Hills, Rollingwood, 
  Barton Creek, Onion Creek, Mansfield Dam, Point Venture, Sunset 
  Valley, San Leanna, Creedmoor, Lost Creek, Camp Mabry, McKinney 
  Falls State Park and Pilot Knob.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 3033 9769 3026 9763 3012 9760 3010 9773
      3012 9779 3017 9784 3021 9789 3020 9796
      3022 9798 3022 9799 3023 9799 3025 9801
      3038 9800 3041 9795 3040 9788 3039 9781
      3036 9775

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

$$

BRADY

1 follow-up statement

619 
WGUS74 KEWX 152105
FFSEWX

Flash Flood Statement
National Weather Service Austin/San Antonio TX
405 PM CDT Sun Aug 15 2021

TXC453-152215-
/O.CON.KEWX.FF.W.0047.000000T0000Z-210815T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Travis TX-
405 PM CDT Sun Aug 15 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 515 PM CDT THIS 
AFTERNOON FOR CENTRAL TRAVIS COUNTY...

At 405 PM CDT, Doppler radar indicated thunderstorms had produced 
heavy rain across southern Travis County. Between 2 and 5 inches of 
rain have fallen with the higest amounts reported over downtown 
Austin. Flash flooding is ongoing in the city of Austin, and some 
minor building flooding has been reported on the UT Campus.

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...
  Austin, Tanglewood Forest, Austin Bergstrom Int Airport, Lakeway, 
  Bee Cave, West Lake Hills, Hudson Bend, The Hills, Rollingwood, 
  Barton Creek, Onion Creek, Mansfield Dam, Point Venture, Sunset 
  Valley, San Leanna, Creedmoor, Lost Creek, Camp Mabry, McKinney 
  Falls State Park and Pilot Knob.

Rainfall has mostly ended for the afternoon, with only some light 
showers expected to produce rainfall amounts less than 1/10 inch 
through 6 pm. However, urban creeks will likely remain flooded and 
dangerous through at least 5 pm.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 3033 9769 3026 9763 3012 9760 3010 9773
      3012 9779 3017 9784 3021 9789 3020 9796
      3022 9798 3022 9799 3023 9799 3025 9801
      3038 9800 3041 9795 3040 9788 3039 9781
      3036 9775

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 15, 12:38 PM CDT	Special Weather Statement	EWX	Blanco	37 min
Aug 15, 12:50 PM CDT	Special Weather Statement	EWX	Lee	40 min
Aug 15, 1:19 PM CDT	Areal Flood Advisory	EWX	Lee	3 hr
Aug 15, 1:31 PM CDT	Special Weather Statement	EWX	Bastrop, Blanco, Hays, Lee, Travis	44 min
Aug 15, 1:43 PM CDT	Areal Flood Advisory	EWX	Bastrop, Lee, Travis	3 hr
Aug 15, 2:19 PM CDT	Special Weather Statement	EWX	Blanco, Caldwell, Comal, Hays, Kendall, Travis	71 min
Aug 15, 3:32 PM CDT	Special Weather Statement	EWX	Bandera	43 min
Aug 15, 4:45 PM CDT	Areal Flood Advisory	EWX	Bexar	3 hr
Aug 15, 5:59 PM CDT	Areal Flood Advisory	EWX	Bandera	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.