Alert archive / Texas / Flash Flood Warnings in 2021

Flash Flood Warning 21, NWS San Angelo, TX

July 11, 2021Tom Green County, Texas

NWS San Angelo, TX issued this flash flood warning at Jul 11, 2021, 7:40 PM 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: Jul 11, 2021, 7:40 PM CDT (00:40 UTC)
Expired: Jul 11, 2021, 10:13 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), 5 km from the middle of the area, began a volume at 00:44 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 00:00Z, 0.7 hours before the alert went out and 169 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: 1782 J/kg
Mixed-layer CIN: -14 J/kg
Mixed-layer LCL: 1445 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: 22 m²/s²
0-3 km storm-relative helicity: 81 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

270 
WGUS54 KSJT 120040
FFWSJT
TXC451-120345-
/O.NEW.KSJT.FF.W.0021.210712T0040Z-210712T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Angelo TX
740 PM CDT Sun Jul 11 2021

The National Weather Service in San Angelo has issued a

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

* Until 1045 PM CDT.

* At 739 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area, including the western and 
  southern San Angelo city limits. Rain gauges report that near 1 
  and a half inches of rain has fallen in the past 40 minutes, and 
  heavy rain is expected to continue for at least the next half hour 
  or hour. 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 Angelo, Lake Nasworthy, Twin Buttes Reservoir and O.c. Fisher 
  Reservoir.

This includes the following Low Water Crossings...
Howard and Webster, College Hills and Millbrook, Jackson From 
Knickerbocker to South Bryant, Southwest Blvd and Loop 306, Parkwood 
and Lindenwood, Huntington and Sunset, Huntington and Sunset, Sul 
Ross At Red Arroyo Crossing, North River and west 1st and Avenue D 
and Madison.

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 3132 10062 3136 10063 3151 10051 3148 10044
      3130 10046

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

$$

SJH

2 follow-up statements

272 
WGUS74 KSJT 120108
FFSSJT

Flash Flood Statement
National Weather Service San Angelo TX
808 PM CDT Sun Jul 11 2021

TXC451-120345-
/O.CON.KSJT.FF.W.0021.000000T0000Z-210712T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Tom Green TX-
808 PM CDT Sun Jul 11 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1045 PM CDT THIS 
EVENING FOR CENTRAL TOM GREEN COUNTY...

At 808 PM CDT, Doppler radar indicated that the heavy rain across 
the warned area is diminishing. However, runoff from earlier heavy 
rain is likely still ongoing and there may be some flooded low water 
crossings and urban areas, so the Flash Flood Warning remains in 
effect.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar.

IMPACT...Flash flooding of small creeks and streams, urban areas,
         highways, streets and underpasses as well as other poor
         drainage and low-lying areas.

Some locations that will experience flash flooding include...
  San Angelo, Lake Nasworthy, Twin Buttes Reservoir and O.c. Fisher 
  Reservoir.

This includes the following Low Water Crossings...
Howard and Webster, College Hills and Millbrook, Jackson From 
Knickerbocker to South Bryant, Southwest Blvd and Loop 306, Parkwood 
and Lindenwood, Huntington and Sunset, Huntington and Sunset, Sul 
Ross At Red Arroyo Crossing, North River and west 1st and Avenue D 
and Madison.

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 3132 10062 3136 10063 3151 10051 3148 10044
      3130 10046

FLASH FLOOD...RADAR INDICATED

$$

SJH

439 
WGUS74 KSJT 120313
FFSSJT

Flash Flood Statement
National Weather Service San Angelo TX
1013 PM CDT Sun Jul 11 2021

TXC451-120323-
/O.CAN.KSJT.FF.W.0021.000000T0000Z-210712T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Tom Green TX-
1013 PM CDT Sun Jul 11 2021

...FLASH FLOOD WARNING IS CANCELLED FOR CENTRAL TOM GREEN COUNTY...

Flood waters have receded and the heavy rain has ended. Flooding is 
no longer expected to pose a threat. Please continue to heed 
remaining road closures.

LAT...LON 3132 10062 3136 10063 3151 10051 3148 10044
      3130 10046

$$

SJH

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 11, 7:16 PM CDT	Areal Flood Advisory	SJT	Irion, Tom Green	3 hr
Jul 11, 7:28 PM CDT	Areal Flood Advisory	SJT	Tom Green	3 hr
Jul 11, 7:57 PM CDT	Areal Flood Advisory	SJT	Brown, Coleman, Concho, McCulloch, Runnels, San Saba	2 hr
Jul 11, 8:19 PM CDT	Special Weather Statement	SJT	Runnels	41 min
Jul 11, 8:59 PM CDT	Areal Flood Advisory	SJT	Brown, Coke, Coleman, Runnels	104 min
Jul 11, 9:18 PM CDT	Special Weather Statement	SJT	Brown	42 min
Jul 12, 10:06 AM CDT	Areal Flood Advisory	SJT	San Saba	3 hr
Jul 12, 11:31 AM CDT	Flash Flood Warning Considerable damage threat	SJT	San Saba	3 hr
Jul 12, 12:36 PM CDT	Areal Flood Advisory	SJT	McCulloch, Mason	114 min
Jul 12, 12:40 PM CDT	Special Weather Statement	SJT	Mason	50 min
Jul 12, 1:30 PM CDT	Areal Flood Advisory	SJT	Concho, McCulloch, Menard	2 hr
Jul 12, 2:23 PM CDT	Areal Flood Warning	SJT	San Saba	3 hr
Jul 12, 3:08 PM CDT	Areal Flood Advisory	SJT	Tom Green	3 hr
Jul 12, 3:19 PM CDT	Flash Flood Warning Considerable damage threat	SJT	Tom Green	3 hr
Jul 12, 3:42 PM CDT	Special Weather Statement	SJT	Nolan	48 min
Jul 12, 3:46 PM CDT	Areal Flood Advisory	SJT	Coke, Nolan	3 hr
Jul 12, 3:59 PM CDT	Special Weather Statement	SJT	Sterling	46 min

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.