Alert archive / Texas / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 601, NWS Norman, OK

November 30, 2018Clay County, Texas

NWS Norman, OK issued this severe thunderstorm warning at Nov 30, 2018, 7:08 PM CST for Clay County, Texas. It was in force for 22 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: Nov 30, 2018, 7:08 PM CST (01:08 UTC)
Expired: Nov 30, 2018, 7:30 PM CST
In force: 22 min
Issued by: NWS Norman, OK
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

County Clay County, TX

The radar

The Altus AFB radar (KFDR), 95 km from the middle of the area, began a volume at 01:12 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
Nov 30, 5:23 PM CST	Tornado Watch	SPC	8 hr

The nearest sounding before it

Fort Worth, TX (KFWD), launched 00:00Z, 1.1 hours before the alert went out and 136 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: 1237 J/kg
Mixed-layer CIN: -13 J/kg
Mixed-layer LCL: 760 m above ground
0-6 km bulk shear: 58 kt
0-1 km storm-relative helicity: 316 m²/s²
0-3 km storm-relative helicity: 360 m²/s²
Significant tornado parameter: 2.3
Supercell composite: 10.9

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.

Hazardous weather outlook, Nov 30, 6:13 PM CST, 55 minutes before

Hazardous Weather Outlook...UPDATED
National Weather Service Norman OK
613 PM CST Fri Nov 30 2018

OKZ004>048-050>052-TXZ083>090-020015-
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-
613 PM CST Fri Nov 30 2018

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 Slight Risk of severe thunderstorms this evening
across portions of Oklahoma and north Texas.

Location...
The Slight Risk area extends east of a line from Freedom to
Clinton to Cache and Randlett Oklahoma to Henrietta Texas. A
Marginal Risk covers the area between the Slight Risk area and a
line from Laverne to Erick Oklahoma to Electra, Texas.

Timing...
The main risk will be through midnight.

Impacts...
Hail up to the size of baseballs, wind gusts 60 to 80 mph, and
tornadoes will be possible.

Discussion...
Scattered thunderstorms will continue to move across much of the
eastern two-thirds of Oklahoma and portions of western north Texas
this evening. Instability will be marginal for severe storms, but
wind fields will be very supportive. This will result in low-
topped supercell storms during the evening hours. The storms will
move quickly to the east or northeast.

.SPOTTER AND EMERGENCY MANAGEMENT STATEMENT...

Storm spotter groups and emergency management personnel across
these risk areas should prepare for severe weather operations
through the evening hours.

.Fog...
Areas of dense fog will continue this evening across northwestern
Oklahoma.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday...

.Fire weather...
Warm, dry, breezy conditions will result in an elevated risk of
wildfires Saturday afternoon across western Oklahoma and adjacent
parts of Texas.

.Winter weather...
Light snow will be possible late Sunday night into early Monday
morning...and again Thursday night, mainly across central and
northern Oklahoma.

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, Nov 30, 6:26 PM CST, 42 minutes before

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Special weather statement, Nov 30, 6:34 PM CST, 34 minutes before

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Special weather statement, Nov 30, 6:36 PM CST, 32 minutes before

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Special weather statement, Nov 30, 6:45 PM CST, 23 minutes before

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Special weather statement, Nov 30, 6:55 PM CST, 13 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE Norman OK
655 PM CST FRI NOV 30 2018

OKZ037-TXZ086-010130-
Tillman OK-Wichita TX-
655 PM CST FRI NOV 30 2018

...SIGNIFICANT WEATHER ADVISORY FOR southeastern Tillman and
northwestern Wichita Counties Until 730 PM CST....

AT 652 PM CST, strong thunderstorms were along a line extending from
9 miles south of Hollister to 4 miles southeast of Electra, moving
northeast at 40 MPH.

HAZARDS INCLUDE...
Hail up to the size of nickels...
Wind gusts to 50 MPH...

LAT...LON 3386 9890 3424 9894 3451 9868 3451 9866
      3434 9866 3433 9861 3416 9861 3413 9855
      3412 9856 3411 9854
TIME...MOT...LOC 0052Z 223DEG 35KT 3420 9890 3397 9888

..speg.

Special weather statement, Nov 30, 7:01 PM CST, 7 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE Norman OK
701 PM CST FRI NOV 30 2018

TXZ090-010130-
Clay TX-
701 PM CST FRI NOV 30 2018

...SIGNIFICANT WEATHER ADVISORY FOR southeastern Clay County Until
730 PM CST....

AT 658 PM CST, strong thunderstorms were along a line extending from
near Henrietta to 3 miles east of Bluegrove, moving east at 45 MPH.

HAZARDS INCLUDE...
Hail up to the size of nickels...
Wind gusts to 50 MPH...

LAT...LON 3390 9822 3399 9795 3396 9796 3395 9797
      3394 9797 3394 9795 3393 9795 3391 9796
      3391 9798 3359 9798 3357 9821
TIME...MOT...LOC 0058Z 255DEG 39KT 3385 9818 3366 9817

..speg.

The office that day

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

Issued	Product	Office	Counties	Lasted
Nov 30, 6:00 PM CST	Special Weather Statement	OUN	Stephens	30 min
Nov 30, 6:22 PM CST	Special Weather Statement	OUN	Jefferson	23 min
Nov 30, 6:26 PM CST	Special Weather Statement	OUN	Grady	34 min
Nov 30, 6:34 PM CST	Special Weather Statement	OUN	Tillman	26 min
Nov 30, 6:45 PM CST	Special Weather Statement	OUN	McClain	30 min
Nov 30, 6:48 PM CST	Severe Thunderstorm Warning	OUN	Canadian, Cleveland, Grady, McClain, Oklahoma	42 min
Nov 30, 7:04 PM CST	Severe Thunderstorm Warning	OUN	Comanche, Cotton, Tillman	41 min
Nov 30, 7:19 PM CST	Special Weather Statement	OUN	Jefferson	26 min
Nov 30, 7:20 PM CST	Special Weather Statement	OUN	Cleveland, McClain	25 min
Nov 30, 7:22 PM CST	Special Weather Statement	OUN	Garvin	23 min
Nov 30, 7:23 PM CST	Special Weather Statement	OUN	Oklahoma	37 min
Nov 30, 7:38 PM CST	Severe Thunderstorm Warning	OUN	Caddo, Comanche	32 min
Nov 30, 7:45 PM CST	Special Weather Statement	OUN	Garvin	30 min
Nov 30, 7:45 PM CST	Severe Thunderstorm Warning	OUN	Comanche, Cotton, Grady, Stephens	45 min
Nov 30, 7:49 PM CST	Special Weather Statement	OUN	Pottawatomie	26 min
Nov 30, 8:08 PM CST	Special Weather Statement	OUN	Payne	37 min
Nov 30, 8:13 PM CST	Special Weather Statement	OUN	Lincoln, Pottawatomie	32 min
Nov 30, 8:16 PM CST	Special Weather Statement	OUN	Carter, Murray	29 min
Nov 30, 8:26 PM CST	Special Weather Statement	OUN	Marshall	34 min
Nov 30, 8:33 PM CST	Severe Thunderstorm Warning	OUN	Lincoln	13 min
Nov 30, 8:35 PM CST	Severe Thunderstorm Warning	OUN	Carter, Johnston, Murray, Pontotoc	25 min
Nov 30, 8:41 PM CST	Special Weather Statement	OUN	Cleveland, McClain, Oklahoma	34 min
Nov 30, 9:03 PM CST	Special Weather Statement	OUN	Coal	27 min
Nov 30, 9:14 PM CST	Severe Thunderstorm Warning	OUN	Atoka, Bryan, Coal, Johnston	46 min
Nov 30, 9:15 PM CST	Special Weather Statement	OUN	Lincoln, Logan, Payne	30 min
Nov 30, 9:17 PM CST	Special Weather Statement	OUN	Seminole	28 min
Nov 30, 6:36 PM CST	Special Weather Statement	OUN	Clay	24 min
Nov 30, 6:55 PM CST	Special Weather Statement	OUN	Wichita	35 min
Nov 30, 7:01 PM CST	Special Weather Statement	OUN	Clay	29 min

Nearby

Severe Thunderstorm Warnings in Texas, 2018 Every severe thunderstorm warning in 2018

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.