Alert archive / Oklahoma / Flash Flood Warnings in 2021

Flash Flood Warning 56, NWS Norman, OK

August 13, 2021Custer County, Washita County, Oklahoma

NWS Norman, OK issued this flash flood warning at Aug 13, 2021, 8:02 PM CDT for Custer County, Washita County, Oklahoma. 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 13, 2021, 8:02 PM CDT (01:02 UTC)
Expired
Aug 13, 2021, 10:37 PM CDT
In force
3 hr
Issued by
NWS Norman, OK
Area
Storm-based polygon
Flood severity
None

Counties Custer County, OK, Washita County, OK

The radar

The Altus AFB radar (KFDR), 126 km from the middle of the area, began a volume at 01:06 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

Amarillo Airport, TX (KAMA), launched 00:00Z, 1.0 hours before the alert went out and 240 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, Amarillo Airport, TX at 00:00Z on 2021-08-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 16 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, Amarillo Airport, TX at 00:00Z on 2021-08-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -5 square meters per square second.193958Sfc1 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
16 J/kg
Mixed-layer CIN
-91 J/kg
Mixed-layer LCL
1845 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
-5 m²/s²
0-3 km storm-relative helicity
8 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

737 
WGUS54 KOUN 140102
FFWOUN
OKC039-149-140415-
/O.NEW.KOUN.FF.W.0056.210814T0102Z-210814T0415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Norman OK
802 PM CDT Fri Aug 13 2021

The National Weather Service in Norman has issued a

* Flash Flood Warning for...
  South Central Custer County in western Oklahoma...
  North Central Washita County in western Oklahoma...

* Until 1115 PM CDT.

* At 802 PM CDT, doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain across the warned area. Between 
  1 and 2 inches of rain have fallen. The expected rainfall rate is 
  2.5 to 3.5 inches in 1 hour. Additional rainfall amounts of 1 to 2 
  inches are possible in the warned area. Flash flooding is ongoing 
  or expected to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar and automated gauges.

  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...
  Clinton, Arapaho, Bessie, Foss and Stafford.

This includes the following highways...
	Interstate 40 between mile markers 53 and 69.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Please report observed flooding to local emergency services or law 
enforcement and request they pass this information to the National 
Weather Service when you can do so safely.

&&

LAT...LON 3557 9914 3565 9904 3563 9890 3532 9896
      3532 9914 3542 9912 3544 9918

FLASH FLOOD...RADAR AND GAUGE INDICATED
EXPECTED RAINFALL...2.5-3.5 INCHES IN 1 HOUR

$$

03
1 follow-up statement
507 
WGUS74 KOUN 140337
FFSOUN

Flash Flood Statement
National Weather Service Norman OK
1037 PM CDT Fri Aug 13 2021

OKC039-149-140347-
/O.CAN.KOUN.FF.W.0056.000000T0000Z-210814T0415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Custer OK-Washita OK-
1037 PM CDT Fri Aug 13 2021

...FLASH FLOOD WARNING IS CANCELLED FOR SOUTH CENTRAL CUSTER AND 
NORTH CENTRAL WASHITA COUNTIES...

Flood waters have receded. The heavy rain has ended, although light 
rainfall will continue. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

LAT...LON 3557 9914 3565 9904 3563 9890 3532 9896
      3532 9914 3542 9912 3544 9918

$$

03

The office that day

Everything else NWS Norman, OK issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 13, 7:08 PM CDTSpecial Weather StatementOUNCuster37 min
Aug 13, 7:24 PM CDTSpecial Weather StatementOUNWashita36 min
Aug 13, 7:27 PM CDTSevere Thunderstorm WarningOUNCuster, Washita48 min
Aug 13, 7:31 PM CDTAreal Flood AdvisoryOUNBeckham, Custer, Washita3 hr
Aug 13, 7:34 PM CDTSpecial Weather StatementOUNCaddo26 min
Aug 13, 7:51 PM CDTSevere Thunderstorm WarningOUNBlaine, Caddo, Custer, Kiowa, Washita39 min
Aug 13, 8:18 PM CDTAreal Flood AdvisoryOUNCaddo, Custer, Kiowa, Washita3 hr
Aug 13, 8:24 PM CDTSpecial Weather StatementOUNCanadian51 min
Aug 13, 8:34 PM CDTSpecial Weather StatementOUNCoal41 min
Aug 13, 8:43 PM CDTSpecial Weather StatementOUNCaddo, Washita47 min
Aug 14, 9:20 AM CDTAreal Flood AdvisoryOUNBryan, Love, Marshall3 hr

Nearby

Flash Flood Warnings in Oklahoma, 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.