Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 118, NWS Norman, OK

April 17, 2017Grady County, McClain County, Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at Apr 17, 2017, 4:21 AM CDT for Grady County, McClain County, Oklahoma. It was in force for 39 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 17, 2017, 4:21 AM CDT (09:21 UTC)
Expired: Apr 17, 2017, 5:00 AM CDT
In force: 39 min
Issued by: NWS Norman, OK
Area: Storm-based polygon
Hail: 1.25 in
Wind: 50.0 mph

Counties Grady County, OK, McClain County, OK

The radar

The Norman radar (KTLX), 50 km from the middle of the area, began a volume at 09:23 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

Norman, OK (KOUN), launched 00:00Z, 9.4 hours before the alert went out and 33 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: 1796 J/kg
Mixed-layer CIN: -33 J/kg
Mixed-layer LCL: 690 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 30 m²/s²
0-3 km storm-relative helicity: 110 m²/s²
Significant tornado parameter: 0.5
Supercell composite: 3.1

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 17, 3:59 AM CDT, 22 minutes earlier.

Area forecast discussion, Apr 17, 3:59 AM CDT, 22 minutes before

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Hazardous weather outlook, Apr 17, 1:35 AM CDT, 2 hours 46 minutes before

Hazardous Weather Outlook...updated
National Weather Service Norman OK
135 AM CDT Mon Apr 17 2017

OKZ004>048-050>052-TXZ083>090-171700-
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-
135 AM CDT Mon Apr 17 2017

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

.DAY ONE...rest of Tonight...

.Thunderstorms...
Isolated strong to severe thunderstorms are possible across
the region. Heavy rain will be the main impact as will small
hail. Organized severe storm risk is low.

.Heavy Rainfall...
Slow-moving thunderstorms may result in locally heavy rainfall.

.DAYS TWO THROUGH SEVEN...Monday through Saturday...

.Thunderstorms...
Thunderstorms will linger across the region through Monday,
especially over northern Texas and the southern half of
Oklahoma. Thunderstorm chances will return on Wednesday
night into Friday. Severe thunderstorms will be possible
on Friday.

.Heavy Rainfall...
Several rounds of showers and thunderstorms through the week
may result in significant rainfall totals for portions of the
region. At this time, the heaviest bouts of rainfall will
occur at the end of the week and across the northern half of
Oklahoma. This, combined with recent rainfall, and the chance
of strong thunderstorms, may result in increasing flooding
concerns late in the week.

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

In the hours before

Special weather statement, Apr 17, 3:38 AM CDT, 43 minutes before

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Special weather statement, Apr 17, 3:41 AM CDT, 40 minutes before

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Local storm report, Apr 17, 3:45 AM CDT, 36 minutes before

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Special weather statement, Apr 17, 3:58 AM CDT, 23 minutes before

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Special weather statement, Apr 17, 4:05 AM CDT, 16 minutes before

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Special weather statement, Apr 17, 4:17 AM 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 16, 7:11 PM CDT	Special Weather Statement	OUN	Washita	34 min
Apr 16, 7:11 PM CDT	Severe Thunderstorm Warning	OUN	Kay	49 min
Apr 16, 7:12 PM CDT	Tornado Warning	OUN	Major	33 min
Apr 16, 7:17 PM CDT	Severe Thunderstorm Warning	OUN	Custer, Washita	24 min
Apr 16, 7:23 PM CDT	Severe Thunderstorm Warning	OUN	Blaine, Dewey	52 min
Apr 16, 7:41 PM CDT	Tornado Warning	OUN	Major	34 min
Apr 16, 7:47 PM CDT	Tornado Warning	OUN	Blaine, Dewey	28 min
Apr 16, 7:57 PM CDT	Severe Thunderstorm Warning	OUN	Kay	48 min
Apr 16, 8:11 PM CDT	Severe Thunderstorm Warning	OUN	Blaine, Dewey, Major	49 min
Apr 16, 8:23 PM CDT	Special Weather Statement	OUN	Custer	37 min
Apr 16, 8:49 PM CDT	Severe Thunderstorm Warning	OUN	Blaine, Dewey, Major	41 min
Apr 16, 9:04 PM CDT	Areal Flood Advisory	OUN	Dewey, Major	3 hr
Apr 16, 9:19 PM CDT	Special Weather Statement	OUN	Garfield	26 min
Apr 16, 9:26 PM CDT	Areal Flood Advisory	OUN	Kay	3 hr
Apr 16, 9:27 PM CDT	Severe Thunderstorm Warning	OUN	Dewey, Major, Woodward	48 min
Apr 16, 9:38 PM CDT	Severe Thunderstorm Warning	OUN	Garfield, Grant	52 min
Apr 16, 10:11 PM CDT	Severe Thunderstorm Warning	OUN	Dewey, Ellis, Roger Mills, Woodward	49 min
Apr 16, 10:49 PM CDT	Severe Thunderstorm Warning	OUN	Ellis, Roger Mills	41 min
Apr 16, 11:18 PM CDT	Areal Flood Advisory	OUN	Dewey, Ellis, Roger Mills	4 hr
Apr 16, 11:30 PM CDT	Severe Thunderstorm Warning	OUN	Ellis, Roger Mills	45 min
Apr 16, 11:48 PM CDT	Special Weather Statement	OUN	Payne	27 min
Apr 17, 12:23 AM CDT	Special Weather Statement	OUN	Ellis	37 min
Apr 17, 2:37 AM CDT	Special Weather Statement	OUN	Roger Mills	23 min
Apr 17, 3:03 AM CDT	Special Weather Statement	OUN	Roger Mills	27 min
Apr 17, 3:41 AM CDT	Special Weather Statement	OUN	Roger Mills	19 min
Apr 17, 4:05 AM CDT	Special Weather Statement	OUN	Grady	25 min
Apr 17, 4:17 AM CDT	Special Weather Statement	OUN	McClain	28 min
Apr 17, 4:30 AM CDT	Special Weather Statement	OUN	Bryan	30 min
Apr 17, 4:57 AM CDT	Special Weather Statement	OUN	Cleveland	33 min
Apr 17, 5:02 AM CDT	Special Weather Statement	OUN	Atoka	43 min
Apr 17, 5:13 AM CDT	Special Weather Statement	OUN	McClain	47 min
Apr 17, 5:17 AM CDT	Special Weather Statement	OUN	Jefferson	28 min
Apr 17, 5:44 AM CDT	Special Weather Statement	OUN	Garvin	31 min
Apr 17, 6:58 AM CDT	Special Weather Statement	OUN	Murray	32 min
Apr 17, 7:59 AM CDT	Special Weather Statement	OUN	Marshall	46 min
Apr 17, 8:23 AM CDT	Flash Flood Warning	OUN	Carter, Love, Marshall	5 hr
Apr 17, 8:57 AM CDT	Special Weather Statement	OUN	Love	48 min
Apr 17, 10:05 AM CDT	Special Weather Statement	OUN	Carter	25 min
Apr 17, 10:17 AM CDT	Special Weather Statement	OUN	Stephens	43 min
Apr 17, 10:37 AM CDT	Areal Flood Advisory	OUN	Comanche, Grady, Stephens	3 hr
Apr 17, 11:34 AM CDT	Special Weather Statement	OUN	Comanche	41 min
Apr 17, 12:06 PM CDT	Special Weather Statement	OUN	Stephens	39 min
Apr 17, 12:44 PM CDT	Special Weather Statement	OUN	Cotton, Jefferson, Stephens	46 min
Apr 17, 2:49 AM CDT	Special Weather Statement	OUN	Wilbarger	26 min
Apr 17, 3:35 AM CDT	Special Weather Statement	OUN	Wichita	25 min
Apr 17, 3:38 AM CDT	Special Weather Statement	OUN	Baylor	22 min
Apr 17, 3:58 AM CDT	Special Weather Statement	OUN	Wichita	32 min

Nearby

Severe Thunderstorm Warnings in Oklahoma, 2017 Every severe thunderstorm warning in 2017

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.