Alert archive / Texas / Flash Flood Warnings in 2021

Flash Flood Warning 41, NWS San Angelo, TX

August 18, 2021Callahan County, Coleman County, Texas

NWS San Angelo, TX issued this flash flood warning at Aug 18, 2021, 1:13 PM CDT for Callahan County, Coleman 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 18, 2021, 1:13 PM CDT (18:13 UTC)
Expired: Aug 18, 2021, 4:00 PM CDT
In force: 3 hr
Issued by: NWS San Angelo, TX
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

Counties Callahan County, TX, Coleman County, TX

The radar

The Dyess AFB radar (KDYX), 48 km from the middle of the area, began a volume at 18:17 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

Fort Worth, TX (KFWD), launched 12:00Z, 6.2 hours before the alert went out and 216 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: 500 J/kg
Mixed-layer CIN: -33 J/kg
Mixed-layer LCL: 580 m above ground
0-6 km bulk shear: 10 kt
0-1 km storm-relative helicity: -15 m²/s²
0-3 km storm-relative helicity: -2 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

034 
WGUS54 KSJT 181813
FFWSJT
TXC059-083-182100-
/O.NEW.KSJT.FF.W.0041.210818T1813Z-210818T2100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Angelo TX
113 PM CDT Wed Aug 18 2021

The National Weather Service in San Angelo has issued a

* Flash Flood Warning for...
  Callahan County in west central Texas...
  Northern Coleman County in west central Texas...

* Until 400 PM CDT.

* At 110 PM CDT, Local law enforcement have reported flooding along 
  Interstate 20, secondary roads, and low water crossings across 
  much of Callahan County. Between 1 and 3 inches of rain have 
  fallen on areas that have already experienced flash flooding, and 
  additional rainfall moving in from the southwest will only 
  exacerbate already ongoing flooding issues.

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

  SOURCE...Law enforcement reported.

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

* Some locations that will experience flash flooding include...
  Interstate 20 in Callahan County, Clyde, Baird, Cross Plains, 
  Novice, Putnam, Oplin, Eula, Dudley, Atwell, Burkett, Silver 
  Valley, Lake Coleman, Goldsboro, Us-283 Near The Coleman-Callahan 
  County Line.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3208 9971 3208 9963 3251 9963 3251 9911
      3208 9912 3208 9920 3196 9920 3186 9971

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

SN

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 18, 4:46 AM CDT	Areal Flood Advisory	SJT	Runnels	119 min
Aug 18, 6:54 AM CDT	Areal Flood Advisory	SJT	Callahan, Coleman	2 hr
Aug 18, 8:12 AM CDT	Flash Flood Warning Considerable damage threat	SJT	Brown, Callahan, Coleman	3 hr
Aug 18, 10:13 AM CDT	Flash Flood Warning	SJT	Callahan	3 hr
Aug 18, 11:25 AM CDT	Areal Flood Advisory	SJT	Shackelford	3 hr
Aug 18, 12:42 PM CDT	Flash Flood Warning	SJT	Runnels	3 hr
Aug 18, 1:56 PM CDT	Areal Flood Advisory	SJT	Coke, Runnels	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.