Alert archive / Oklahoma / Flash Flood Warnings in 2021

Flash Flood Warning 57, NWS Norman, OK

August 16, 2021Harper County, Oklahoma

NWS Norman, OK issued this flash flood warning at Aug 16, 2021, 9:23 AM CDT for Harper 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 16, 2021, 9:23 AM CDT (14:23 UTC)
Expired
Aug 16, 2021, 12:30 PM CDT
In force
3 hr
Issued by
NWS Norman, OK
Area
Storm-based polygon
Flood severity
None

County Harper County, OK

The radar

The Dodge City radar (KDDC), 123 km from the middle of the area, began a volume at 14:25 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

Dodge City, (KDDC), launched 12:00Z, 2.4 hours before the alert went out and 124 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, Dodge City, at 12:00Z on 2021-08-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 360 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, Dodge City, at 12:00Z on 2021-08-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 131 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
360 J/kg
Mixed-layer CIN
-169 J/kg
Mixed-layer LCL
970 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
131 m²/s²
0-3 km storm-relative helicity
182 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.3

Open this sounding in Storm Lab

The text

As transmitted.

347 
WGUS54 KOUN 161423
FFWOUN
OKC059-161730-
/O.NEW.KOUN.FF.W.0057.210816T1423Z-210816T1730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Norman OK
923 AM CDT Mon Aug 16 2021

The National Weather Service in Norman has issued a

* Flash Flood Warning for...
  Southwestern Harper County in northwestern Oklahoma...

* Until 1230 PM CDT.

* At 923 AM 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...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...
  Laverne.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3674 10000 3674 9990 3659 9989 3659 9994
      3659 10000 3661 10000 3664 10000 3669 10000

FLASH FLOOD...RADAR INDICATED

$$

30

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 16, 6:22 AM CDTSpecial Weather StatementOUNEllis23 min
Aug 16, 6:49 AM CDTSpecial Weather StatementOUNEllis26 min
Aug 16, 8:36 AM CDTSpecial Weather StatementOUNHarper24 min
Aug 16, 8:45 AM CDTAreal Flood AdvisoryOUNHarper3 hr
Aug 16, 4:28 PM CDTSpecial Weather StatementOUNNoble47 min
Aug 16, 4:30 PM CDTSpecial Weather StatementOUNWashita45 min
Aug 16, 6:36 PM CDTSpecial Weather StatementOUNOklahoma24 min
Aug 16, 6:43 PM CDTSpecial Weather StatementOUNPayne32 min
Aug 16, 6:50 PM CDTSevere Thunderstorm WarningOUNCanadian, Cleveland, Oklahoma40 min
Aug 16, 6:55 PM CDTAreal Flood AdvisoryOUNOklahoma3 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.