Alert archive / Oklahoma / Flash Flood Warnings in 2021

Flash Flood Warning 50, NWS Norman, OK

July 19, 2021Johnston County, Pontotoc County, Oklahoma

NWS Norman, OK issued this flash flood warning at Jul 19, 2021, 8:12 AM CDT for Johnston County, Pontotoc County, Oklahoma. It was in force for 3 hr. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Jul 19, 2021, 8:12 AM CDT (13:12 UTC)
Expired: Jul 19, 2021, 11:15 AM CDT
In force: 3 hr
Issued by: NWS Norman, OK
Area: Storm-based polygon
Flood severity: None

Counties Johnston County, OK, Pontotoc County, OK

The radar

The Norman radar (KTLX), 105 km from the middle of the area, began a volume at 13:13 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.

What was reported inside it

Time	Report	Where	Remark
Jul 19, 10:00 AM CDT	FLASH FLOOD	1 N Pontotoc, OK	ONE FOOT OF FLOWING WATER OVER ROADWAY.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Norman, OK (KOUN), launched 12:00Z, 1.2 hours before the alert went out and 101 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: 930 J/kg
Mixed-layer CIN: -19 J/kg
Mixed-layer LCL: 716 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: -23 m²/s²
0-3 km storm-relative helicity: -11 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

293 
WGUS54 KOUN 191312
FFWOUN
OKC069-123-191615-
/O.NEW.KOUN.FF.W.0050.210719T1312Z-210719T1615Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Norman OK
812 AM CDT Mon Jul 19 2021

The National Weather Service in Norman has issued a

* Flash Flood Warning for...
  South Central Pontotoc County in east central Oklahoma...
  Northern Johnston County in southeastern Oklahoma...

* Until 1115 AM CDT.

* At 812 AM CDT, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain across the warned area. Between 
  2 and 3 inches of rain have fallen. The expected rainfall rate is 
  1.5 to 2.5 inches in 1 hour. Additional rainfall amounts of 1 to 
  1.5 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...
  Fittstown and Pontotoc.

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 3451 9666 3457 9675 3460 9674 3461 9670
      3461 9664 3454 9653 3446 9660 3447 9662

FLASH FLOOD...RADAR AND GAUGE INDICATED
EXPECTED RAINFALL...1.5-2.5 INCHES IN 1 HOUR

$$

03

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 18, 7:02 PM CDT	Severe Thunderstorm Warning	OUN	Tillman	43 min
Jul 18, 7:06 PM CDT	Special Weather Statement	OUN	Cleveland	24 min
Jul 18, 7:19 PM CDT	Areal Flood Advisory	OUN	Cleveland	4 hr
Jul 18, 7:23 PM CDT	Areal Flood Advisory	OUN	Atoka, Coal, Hughes	4 hr
Jul 18, 7:27 PM CDT	Special Weather Statement	OUN	Grady	33 min
Jul 18, 7:36 PM CDT	Special Weather Statement	OUN	Beckham	24 min
Jul 18, 7:58 PM CDT	Special Weather Statement	OUN	Pontotoc	32 min
Jul 18, 8:21 PM CDT	Special Weather Statement	OUN	Greer	24 min
Jul 18, 8:56 PM CDT	Special Weather Statement	OUN	Jackson, Kiowa	49 min
Jul 18, 8:58 PM CDT	Special Weather Statement	OUN	Carter, Garvin, Murray	32 min
Jul 18, 9:20 PM CDT	Severe Thunderstorm Warning	OUN	Johnston, Marshall	28 min
Jul 18, 9:59 PM CDT	Special Weather Statement	OUN	Tillman	61 min
Jul 18, 10:03 PM CDT	Areal Flood Advisory	OUN	Carter, Garvin, Johnston, McClain, Murray, Pottawatomie	4 hr
Jul 18, 10:10 PM CDT	Areal Flood Advisory	OUN	Harmon, Jackson	5 hr
Jul 18, 10:49 PM CDT	Special Weather Statement	OUN	Pottawatomie	26 min
Jul 19, 12:18 AM CDT	Areal Flood Advisory	OUN	Caddo, Comanche, Grady	3 hr
Jul 19, 1:03 AM CDT	Areal Flood Advisory	OUN	Comanche	3 hr
Jul 19, 4:01 AM CDT	Areal Flood Advisory	OUN	Carter, Jefferson, Love, Marshall, Murray, Stephens	5 hr
Jul 19, 7:46 AM CDT	Areal Flood Advisory	OUN	Johnston, Pontotoc	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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.