Alert archive / Texas / Flash Flood Warnings in 2021

Flash Flood Warning 32, NWS San Angelo, TX

August 17, 2021Tom Green County, Texas

NWS San Angelo, TX issued this flash flood warning at Aug 17, 2021, 8:55 AM CDT for Tom Green 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
Aug 17, 2021, 8:55 AM CDT (13:55 UTC)
Expired
Aug 17, 2021, 12:00 PM CDT
In force
3 hr
Issued by
NWS San Angelo, TX
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

County Tom Green County, TX

The radar

The San Angelo radar (KSJT), 24 km from the middle of the area, began a volume at 13:55 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

Midland Regional, TX (KMAF), launched 12:00Z, 1.9 hours before the alert went out and 196 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, Midland Regional, TX at 12:00Z on 2021-08-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 134 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, Midland Regional, TX at 12:00Z on 2021-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 59 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
134 J/kg
Mixed-layer CIN
-49 J/kg
Mixed-layer LCL
779 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
59 m²/s²
0-3 km storm-relative helicity
91 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

500 
WGUS54 KSJT 171355
FFWSJT
TXC451-171700-
/O.NEW.KSJT.FF.W.0032.210817T1355Z-210817T1700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Angelo TX
855 AM CDT Tue Aug 17 2021

The National Weather Service in San Angelo has issued a

* Flash Flood Warning for...
  Southeastern Tom Green County in west central Texas...

* Until noon CDT.

* At 851 AM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1.5 and 2.5 inches of 
  rain have fallen. Flash flooding is ongoing or expected to begin 
  shortly. Additional heavy rainfall will cause flash flooding of 
  creeks and low water crossings.

  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 Angelo and Vancourt.

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 3109 10042 3136 10051 3135 10030 3137 10011
      3109 10012

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

$$

21

The office that day

Everything else NWS San Angelo, TX issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 17, 5:34 AM CDTAreal Flood AdvisorySJTIrion, Sterling, Tom Green2 hr
Aug 17, 6:08 AM CDTFlash Flood WarningSJTIrion, Tom Green112 min
Aug 17, 6:55 AM CDTFlash Flood Warning Considerable damage threatSJTTom Green110 min
Aug 17, 7:10 AM CDTFlash Flood Warning Considerable damage threatSJTIrion3 hr
Aug 17, 7:33 AM CDTFlash Flood Warning Considerable damage threatSJTIrion, Tom Green3 hr
Aug 17, 7:47 AM CDTFlash Flood Warning Considerable damage threatSJTIrion, Tom Green3 hr
Aug 17, 8:39 AM CDTFlash Flood Warning Considerable damage threatSJTTom Green111 min
Aug 17, 9:04 AM CDTAreal Flood AdvisorySJTSchleicher3 hr
Aug 17, 9:36 AM CDTFlash Flood Warning Considerable damage threatSJTSchleicher3 hr
Aug 17, 9:54 AM CDTRiver Flood WarningSJTIrion, Tom Green22 hr
Aug 17, 10:31 AM CDTAreal Flood WarningSJTIrion, Tom Green3 hr
Aug 17, 10:36 AM CDTAreal Flood AdvisorySJTConcho, Menard3 hr
Aug 17, 11:10 AM CDTAreal Flood AdvisorySJTMcCulloch3 hr
Aug 17, 12:19 PM CDTFlash Flood Warning Considerable damage threatSJTSchleicher3 hr
Aug 17, 12:34 PM CDTFlash Flood WatchSJTCoke, Concho, Crockett, Irion, Menard, Runnels and 4 more16 hr
Aug 17, 12:49 PM CDTFlash Flood Warning Considerable damage threatSJTSchleicher, Sutton3 hr
Aug 17, 1:50 PM CDTSpecial Weather StatementSJTKimble40 min
Aug 17, 2:26 PM CDTFlash Flood Warning Considerable damage threatSJTKimble, Sutton2 hr
Aug 17, 3:10 PM CDTAreal Flood WarningSJTIrion, Tom Green6 hr
Aug 17, 4:24 PM CDTFlash Flood WarningSJTKimble111 min
Aug 17, 6:33 PM CDTRiver Flood WarningSJTTom Green10 hr

Nearby

Flash Flood Warnings in Texas, 2021Every 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.