Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 182, NWS Norman, OK

April 28, 2020Grady County, Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at Apr 28, 2020, 6:22 PM CDT for Grady County, Oklahoma. It was in force for 53 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Apr 28, 2020, 6:22 PM CDT (23:22 UTC)
Expired: Apr 28, 2020, 7:15 PM CDT
In force: 53 min
Issued by: NWS Norman, OK
Area: Storm-based polygon
Hail: 2.0 in
Wind: 60.0 mph

County Grady County, OK

The radar

The Norman radar (KTLX), 65 km from the middle of the area, began a volume at 23:21 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Apr 28, 3:30 PM CDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Norman, OK (KOUN), launched 12:00Z, 11.4 hours before the alert went out and 49 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: 1292 J/kg
Mixed-layer CIN: -331 J/kg
Mixed-layer LCL: 1080 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 213 m²/s²
0-3 km storm-relative helicity: 244 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -1.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Norman, OK wrote its last area forecast discussion before this severe thunderstorm warning went out at Apr 28, 6:15 PM CDT, 7 minutes earlier.

Area forecast discussion, Apr 28, 6:15 PM CDT, 7 minutes before

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Hazardous weather outlook, Apr 28, 4:36 AM CDT, 13 hours 46 minutes before

Hazardous Weather Outlook
National Weather Service Norman OK
436 AM CDT Tue Apr 28 2020

OKZ004>048-050>052-TXZ083>090-290945-
Harper-Woods-Alfalfa-Grant-Kay-Ellis-Woodward-Major-Garfield-
Noble-Roger Mills-Dewey-Custer-Blaine-Kingfisher-Logan-Payne-
Beckham-Washita-Caddo-Canadian-Oklahoma-Lincoln-Grady-McClain-
Cleveland-Pottawatomie-Seminole-Hughes-Harmon-Greer-Kiowa-Jackson-
Tillman-Comanche-Stephens-Garvin-Murray-Pontotoc-Coal-Cotton-
Jefferson-Carter-Johnston-Atoka-Love-Marshall-Bryan-Hardeman-
Foard-Wilbarger-Wichita-Knox-Baylor-Archer-Clay-
436 AM CDT Tue Apr 28 2020

This hazardous weather outlook is for portions of northern...
western...central...and southern Oklahoma...and western north
Texas.

.DAY ONE...Through tonight...

.Thunderstorms...
There is a moderate risk of severe weather late Tuesday afternoon
and evening across eastern and southeastern Oklahoma, mainly along
and east of a line from Shawnee to Ardmore. An enhanced risk of
severe weather also extends further west to near and just east of
a line from Ponca City, to El Reno, to Wichita Falls. Severe
thunderstorms capable of producing very large hail up to the size
of baseballs and damaging wind gusts in excess of 70 to 80 mph
will be possible. One or two tornadoes will also be possible.

Thunderstorms are expected to develop across northern Oklahoma
between 3 pm and 5 pm this afternoon, and then build southward
along a cold front into central and southern Oklahoma by early
evening. Storms will likely merge into a squall line, with an
increasing damaging wind risk across southern Oklahoma tonight,
and quickly move across the Red River near midnight.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday...

.Thunderstorms...
Low thunderstorm chances return Saturday and Sunday, and then
again Monday night. Strong to severe storms will be possible.

Get graphics and more details at weather.gov/norman...and follow
our weather forecast office on Twitter and Facebook.

In the hours before

Local storm report, Apr 28, 5:44 PM CDT, 38 minutes before

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Local storm report, Apr 28, 6:10 PM CDT, 12 minutes before

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Local storm report, Apr 28, 6:11 PM CDT, 11 minutes before

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Local storm report, Apr 28, 6:13 PM CDT, 9 minutes before

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Local storm report, Apr 28, 6:16 PM CDT, 6 minutes before

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Local storm report, Apr 28, 6:18 PM CDT, 4 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 28, 3:44 PM CDT	Special Weather Statement	OUN	Kay	31 min
Apr 28, 4:02 PM CDT	Severe Thunderstorm Warning	OUN	Noble	43 min
Apr 28, 4:12 PM CDT	Special Weather Statement	OUN	Logan	33 min
Apr 28, 4:18 PM CDT	Severe Thunderstorm Warning	OUN	Garfield, Logan, Noble, Payne	42 min
Apr 28, 4:26 PM CDT	Special Weather Statement	OUN	Kingfisher	34 min
Apr 28, 4:37 PM CDT	Severe Thunderstorm Warning	OUN	Canadian, Kingfisher, Logan, Oklahoma	53 min
Apr 28, 4:44 PM CDT	Severe Thunderstorm Warning	OUN	Noble, Payne	31 min
Apr 28, 4:45 PM CDT	Severe Thunderstorm Warning	OUN	Logan, Payne	30 min
Apr 28, 5:15 PM CDT	Severe Thunderstorm Warning	OUN	Lincoln, Logan, Oklahoma	45 min
Apr 28, 5:15 PM CDT	Severe Thunderstorm Warning	OUN	Noble, Payne	45 min
Apr 28, 5:18 PM CDT	Severe Thunderstorm Warning	OUN	Canadian, Oklahoma	27 min
Apr 28, 5:27 PM CDT	Severe Thunderstorm Warning	OUN	Noble, Payne	33 min
Apr 28, 5:43 PM CDT	Severe Thunderstorm Warning	OUN	Canadian, Cleveland, Oklahoma	25 min
Apr 28, 5:46 PM CDT	Severe Thunderstorm Warning	OUN	Noble, Payne	44 min
Apr 28, 5:49 PM CDT	Severe Thunderstorm Warning	OUN	Canadian, Cleveland, Grady, McClain, Oklahoma	26 min
Apr 28, 5:52 PM CDT	Severe Thunderstorm Warning	OUN	Lincoln, Logan, Oklahoma	25 min
Apr 28, 6:03 PM CDT	Severe Thunderstorm Warning	OUN	Logan, Oklahoma	27 min
Apr 28, 6:06 PM CDT	Severe Thunderstorm Warning	OUN	Canadian, Grady	24 min
Apr 28, 6:12 PM CDT	Severe Thunderstorm Warning	OUN	Canadian, Cleveland, Grady, McClain, Oklahoma	48 min
Apr 28, 6:17 PM CDT	Severe Thunderstorm Warning	OUN	Lincoln, Payne	43 min
Apr 28, 6:31 PM CDT	Special Weather Statement	OUN	Lincoln	14 min
Apr 28, 6:49 PM CDT	Special Weather Statement	OUN	Lincoln	26 min
Apr 28, 6:54 PM CDT	Severe Thunderstorm Warning	OUN	Lincoln, Oklahoma, Pottawatomie	36 min
Apr 28, 6:58 PM CDT	Severe Thunderstorm Warning	OUN	McClain	32 min
Apr 27, 11:05 PM CDT	Special Weather Statement	OUN	Baylor	40 min
Apr 27, 11:13 PM CDT	Severe Thunderstorm Warning	OUN	Archer, Baylor	33 min
Apr 27, 11:32 PM CDT	Special Weather Statement	OUN	Wichita	28 min
Apr 28, 12:14 AM CDT	Special Weather Statement	OUN	Wichita	31 min
Apr 28, 12:27 AM CDT	Special Weather Statement	OUN	Archer	33 min
Apr 28, 12:34 AM CDT	Severe Thunderstorm Warning	OUN	Archer	26 min
Apr 28, 12:56 AM CDT	Severe Thunderstorm Warning	OUN	Archer	49 min
Apr 28, 1:14 AM CDT	Special Weather Statement	OUN	Archer	31 min
Apr 28, 1:17 AM CDT	Severe Thunderstorm Warning	OUN	Archer, Clay	28 min
Apr 28, 1:42 AM CDT	Severe Thunderstorm Warning	OUN	Archer, Clay	33 min
Apr 28, 2:13 AM CDT	Special Weather Statement	OUN	Clay	32 min

Nearby

Severe Thunderstorm Warnings in Oklahoma, 2020 Every severe thunderstorm warning in 2020

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.