Alert archive / Oklahoma / Flash Flood Warnings in 2021

Flash Flood Warning 16, NWS Norman, OK

May 16, 2021Jefferson County, Oklahoma

NWS Norman, OK issued this flash flood warning at May 16, 2021, 6:42 PM CDT for Jefferson 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: May 16, 2021, 6:42 PM CDT (23:42 UTC)
Expired: May 16, 2021, 9:45 PM CDT
In force: 3 hr
Issued by: NWS Norman, OK
Area: Storm-based polygon
Flood severity: None

County Jefferson County, OK

The radar

The Altus AFB radar (KFDR), 111 km from the middle of the area, began a volume at 23:46 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 12:00Z, 11.7 hours before the alert went out and 378 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1470 m above ground
0-6 km bulk shear: 11 kt
0-1 km storm-relative helicity: -57 m²/s²
0-3 km storm-relative helicity: -16 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

318 
WGUS54 KOUN 162342
FFWOUN
OKC067-170245-
/O.NEW.KOUN.FF.W.0016.210516T2342Z-210517T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Norman OK
642 PM CDT Sun May 16 2021

The National Weather Service in Norman has issued a

* Flash Flood Warning for...
  South Central Jefferson County in southern Oklahoma...

* Until 945 PM CDT.

* At 642 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 3 and 5 inches of rain 
  have fallen. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Doppler radar.

  IMPACT...Flooding of small creeks and streams, urban areas,
           highways, streets and underpasses as well as other
           drainage and low lying areas.

* Some locations that will experience flash flooding include...
  mainly rural areas of South Central Jefferson County

Additional rainfall amounts of 1 to 3 inches are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Excessive runoff from heavy rainfall will cause flooding of small 
creeks and streams, country roads, farmland, and other low lying 
spots.

&&

LAT...LON 3399 9795 3403 9783 3402 9778 3396 9775
      3394 9776 3393 9776 3392 9795 3393 9795
      3397 9795

FLASH FLOOD...RADAR INDICATED

$$

MAD

The office that day

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

Issued	Product	Office	Counties	Lasted
May 16, 3:36 AM CDT	Flood Watch	OUN	Atoka, Bryan, Caddo, Canadian, Carter, Cleveland and 25 more	3 days
May 16, 12:38 PM CDT	Areal Flood Advisory	OUN	Cleveland, Grady, McClain, Oklahoma	3 hr
May 16, 12:48 PM CDT	Areal Flood Advisory	OUN	Comanche, Grady, Stephens	4 hr
May 16, 12:52 PM CDT	Areal Flood Advisory	OUN	Atoka, Bryan, Carter, Coal, Johnston, Marshall and 2 more	3 hr
May 16, 1:13 PM CDT	Areal Flood Warning	OUN	Cleveland, Oklahoma	4 hr
May 16, 3:19 PM CDT	Areal Flood Advisory	OUN	Lincoln, Logan, Oklahoma	4 hr
May 16, 3:27 PM CDT	Areal Flood Advisory	OUN	Cleveland, Garvin, Grady, McClain, Pontotoc, Pottawatomie and 2 more	5 hr
May 16, 3:39 PM CDT	Special Weather Statement	OUN	Cotton	36 min
May 16, 3:40 PM CDT	Special Weather Statement	OUN	Stephens	35 min
May 16, 3:49 PM CDT	Special Weather Statement	OUN	Tillman	26 min
May 16, 3:59 PM CDT	Special Weather Statement	OUN	Seminole	31 min
May 16, 4:06 PM CDT	Special Weather Statement	OUN	Stephens	24 min
May 16, 4:13 PM CDT	Special Weather Statement	OUN	Carter	32 min
May 16, 4:15 PM CDT	Special Weather Statement	OUN	Jefferson	15 min
May 16, 4:17 PM CDT	Special Weather Statement	OUN	Pontotoc	28 min
May 16, 4:30 PM CDT	Tornado Warning	OUN	Carter, Jefferson, Stephens	30 min
May 16, 4:38 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Garvin, Jefferson, Love, Murray, Pontotoc and 1 more	52 min
May 16, 4:45 PM CDT	Special Weather Statement	OUN	Seminole	30 min
May 16, 5:19 PM CDT	Flash Flood Warning	OUN	Jefferson, Stephens	3 hr
May 16, 5:22 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Jefferson, Love	38 min
May 16, 5:25 PM CDT	Areal Flood Advisory	OUN	Carter, Murray, Stephens	3 hr
May 16, 5:57 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Jefferson, Love, Marshall	78 min
May 16, 6:16 PM CDT	Areal Flood Advisory	OUN	Jefferson	3 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.