Alert archive / Oklahoma / Flash Flood Warnings in 2021

Flash Flood Warning 42, NWS Norman, OK

July 1, 2021Logan County, Oklahoma

NWS Norman, OK issued this flash flood warning at Jul 1, 2021, 3:34 PM CDT for Logan 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: Jul 1, 2021, 3:34 PM CDT (20:34 UTC)
Expired: Jul 1, 2021, 7:00 PM CDT
In force: 3 hr
Issued by: NWS Norman, OK
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Logan County, OK

The radar

The Norman radar (KTLX), 58 km from the middle of the area, began a volume at 20:38 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, 8.6 hours before the alert went out and 304 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: 789 J/kg
Mixed-layer CIN: -26 J/kg
Mixed-layer LCL: 895 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 61 m²/s²
0-3 km storm-relative helicity: 99 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 1.2

Open this sounding in Storm Lab

The text

As transmitted.

958 
WGUS54 KOUN 012034
FFWOUN
OKC083-020000-
/O.NEW.KOUN.FF.W.0042.210701T2034Z-210702T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Norman OK
334 PM CDT Thu Jul 1 2021

The National Weather Service in Norman has issued a

* Flash Flood Warning for...
  Southern Logan County in central Oklahoma...

* Until 700 PM CDT.

* At 334 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 3 inches of rain 
  have fallen. Flash flooding is ongoing or expected to begin 
  shortly.

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

  SOURCE...Doppler radar.

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

* Some locations that will experience flash flooding include...
  Guthrie, Cashion, Cedar Valley, Cimarron City, Meridian, Seward 
  and Navina.

This includes the following highways...
	Interstate 35 between mile markers 151 and 159.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3577 9767 3590 9767 3590 9725 3578 9725

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL...0.75-1 INCH IN 1 HOUR 

$$

JP

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 1, 8:47 AM CDT	River Flood Advisory	OUN	Blaine, Caddo, Canadian, Custer	37 hr
Jul 1, 12:07 PM CDT	Areal Flood Advisory	OUN	Canadian, Cleveland, Lincoln, Oklahoma, Pottawatomie	3 hr
Jul 1, 12:38 PM CDT	Areal Flood Advisory	OUN	Woods	3 hr
Jul 1, 1:02 PM CDT	Areal Flood Advisory	OUN	Garfield, Grant	3 hr
Jul 1, 1:23 PM CDT	Special Weather Statement	OUN	Pottawatomie	37 min
Jul 1, 1:27 PM CDT	Areal Flood Advisory	OUN	Pottawatomie, Seminole	3 hr
Jul 1, 1:31 PM CDT	Areal Flood Advisory	OUN	Blaine, Canadian, Kingfisher	3 hr
Jul 1, 1:36 PM CDT	Areal Flood Advisory	OUN	Cleveland, McClain, Pottawatomie	3 hr
Jul 1, 1:37 PM CDT	Special Weather Statement	OUN	Canadian	38 min
Jul 1, 2:18 PM CDT	Flash Flood Warning	OUN	Canadian, Kingfisher, Logan, Oklahoma	6 hr
Jul 1, 2:23 PM CDT	Areal Flood Advisory	OUN	Logan	5 hr
Jul 1, 2:51 PM CDT	Special Weather Statement	OUN	Logan	24 min
Jul 1, 3:42 PM CDT	Special Weather Statement	OUN	Oklahoma	33 min
Jul 1, 3:52 PM CDT	Flash Flood Warning Considerable damage threat	OUN	Canadian, Cleveland, Grady, McClain, Oklahoma	3 hr
Jul 1, 4:23 PM CDT	Flash Flood Warning Considerable damage threat	OUN	Caddo, Cleveland, Comanche, Garvin, Grady, McClain	3 hr
Jul 1, 4:50 PM CDT	Areal Flood Advisory	OUN	Lincoln, Pottawatomie	3 hr
Jul 1, 5:39 PM CDT	Areal Flood Advisory	OUN	Stephens	3 hr
Jul 1, 5:43 PM CDT	Areal Flood Advisory	OUN	Garvin, Stephens	3 hr
Jul 1, 5:46 PM CDT	River Flood Advisory	OUN	Lincoln, Oklahoma, Pottawatomie	9 hr

Nearby

Flash Flood Warnings in Oklahoma, 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.