Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 116, NWS Norman, OK

April 23, 2021Clay County, Texas; 5 counties in Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at Apr 23, 2021, 9:12 PM CDT for Clay County, Texas; 5 counties in Oklahoma. It was in force for 48 min. 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: Apr 23, 2021, 9:12 PM CDT (02:12 UTC)
Expired: Apr 23, 2021, 10:00 PM CDT
In force: 48 min
Issued by: NWS Norman, OK
Area: Storm-based polygon
Hail: 1.5 in
Wind: 60.0 mph

Counties Carter County, OK, Jefferson County, OK, Love County, OK, Murray County, OK, Stephens County, OK, Clay County, TX

The radar

The Altus AFB radar (KFDR), 143 km from the middle of the area, began a volume at 02:16 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
Apr 23, 9:18 PM CDT	HAIL 1	1 Ssw Ryan, OK

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

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched one storm report to this severe thunderstorm warning; the first came 6 minutes after it went out.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

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 23, 8:02 PM CDT	Severe Thunderstorm Watch	SPC	4 hr

The nearest sounding before it

Fort Worth, TX (KFWD), launched 00:00Z, 2.2 hours before the alert went out and 126 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: 364 J/kg
Mixed-layer CIN: -58 J/kg
Mixed-layer LCL: 812 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: 252 m²/s²
0-3 km storm-relative helicity: 291 m²/s²
Significant tornado parameter: 0.6
Supercell composite: 7.5

Open this sounding in Storm Lab

The text

As transmitted.

018 
WUUS54 KOUN 240212
SVROUN
OKC019-067-085-099-137-TXC077-240300-
/O.NEW.KOUN.SV.W.0116.210424T0212Z-210424T0300Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Norman OK
912 PM CDT Fri Apr 23 2021

The National Weather Service in Norman has issued a

* Severe Thunderstorm Warning for...
  Jefferson County in southern Oklahoma...
  Northwestern Love County in southern Oklahoma...
  Southeastern Stephens County in southern Oklahoma...
  Western Carter County in southern Oklahoma...
  West central Murray County in southern Oklahoma...
  East central Clay County in northern Texas...

* Until 1000 PM CDT.

* At 912 PM CDT, severe thunderstorms were located along a line
  extending from near Loco to 5 miles southwest of Ringling to 4
  miles west of Terral, moving east at 50 mph.

  HAZARD...Ping pong ball size hail and 60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...People and animals outdoors will be injured. Expect hail 
           damage to roofs, siding, windows, and vehicles. Expect 
           wind damage to roofs, siding, and trees.

* Locations impacted include...
  Lone Grove, Healdton, Wilson, Ringling, Ryan, Terral, Loco, Ratliff
  City, Leon, Graham, Pooleville, Rubottom, Burneyville, Grady, Milo,
  Oscar, Cornish, Fox, Courtney and Petersburg.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3391 9747 3392 9750 3390 9759 3395 9759
      3399 9767 3385 9787 3391 9810 3441 9772
      3448 9729 3387 9725 3386 9728 3389 9731
      3385 9733 3388 9733 3382 9737 3382 9743
TIME...MOT...LOC 0212Z 267DEG 42KT 3434 9763 3414 9768 3388 9801 

HAIL...1.50IN
WIND...60MPH
 
$$

TL

1 follow-up statement

717 
WWUS54 KOUN 240223
SVSOUN

Severe Weather Statement
National Weather Service Norman OK
923 PM CDT Fri Apr 23 2021

OKC019-067-085-099-137-TXC077-240300-
/O.CON.KOUN.SV.W.0116.000000T0000Z-210424T0300Z/
Jefferson OK-Love OK-Stephens OK-Carter OK-Murray OK-Clay TX-
923 PM CDT Fri Apr 23 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1000 PM CDT
FOR JEFFERSON...NORTHWESTERN LOVE...SOUTHEASTERN STEPHENS...WESTERN
CARTER...WEST CENTRAL MURRAY AND EAST CENTRAL CLAY COUNTIES...

At 918 PM CDT, quarter size hail was reported one mile southwest of 
Ryan.

At 922 PM CDT, severe thunderstorms were located along a line
extending from 5 miles south of Ratliff City to near Ringling to near
Terral, moving east at 40 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Trained weather spotters.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Lone Grove, Healdton, Wilson, Ringling, Ryan, Terral, Loco, Ratliff
City, Leon, Graham, Pooleville, Rubottom, Burneyville, Grady, Milo,
Oscar, Cornish, Fox, Courtney and Petersburg.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3391 9747 3392 9750 3390 9759 3395 9759
      3399 9767 3385 9787 3391 9810 3441 9772
      3448 9729 3387 9725 3386 9728 3389 9731
      3385 9733 3388 9733 3382 9737 3382 9743
TIME...MOT...LOC 0222Z 273DEG 34KT 3438 9753 3418 9758 3392 9791 

HAIL...1.00IN
WIND...60MPH
 
$$

TL

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 23, 6:27 PM CDT, 2 hours 45 minutes earlier.

Area forecast discussion, Apr 23, 6:27 PM CDT, 2 hours 45 minutes before

Area Forecast Discussion
National Weather Service Norman OK
627 PM CDT Fri Apr 23 2021

...New AVIATION, UPPER AIR...

.UPDATE...
Issued at 1032 AM CDT Fri Apr 23 2021

The upper trough is currently tracking across CO/NM and the
surface low continues to develop over the TX panhandle. Low-
level moisture will continue to advect into our area through
this evening. Latest mesoanalysis data shows steep lapse rates in
place and increasing MUCAPE indicates destabilization is
underway over western/southern Oklahoma and north TX. Increased
POPs for 18Z Friday through 06Z Saturday, as CAMS suggest
widespread convection across portions of western north Texas and
southern Oklahoma around mid- day. Some of these storms may be
strong to severe.

The surface low is prog'd to track southeast along the Red River
and strong to severe thunderstorms are likely to develop over
southwest Oklahoma by early evening. CAMS suggest storms will grow
upscale along the front with perhaps a bowing segment as it moves
through south-central Oklahoma later this evening. Very large
hail, damaging winds, and an isolated tornado are possible.

Thompson

&&

.SHORT TERM...
(This evening through Saturday)
Issued at 159 PM CDT Fri Apr 23 2021

The upper trough is currently tracking across CO/NM and the
surface low continues to develop over the TX panhandle. Low-
level moisture will continue to advect into our area through
this evening. Latest mesoanalysis data shows steep lapse rates in
place and increasing MUCAPE indicates destabilization is
underway over western/southern Oklahoma and north TX. Increased
POPs for 18Z Friday through 06Z Saturday, as CAMS suggest
widespread convection across portions of western north Texas and
southern Oklahoma around mid- day. Some of these storms may be
strong to severe.

The surface low is prog'd to track southeast along the Red River
and strong to severe thunderstorms are likely to develop over
southwest Oklahoma by early evening. CAMS suggest storms will grow
upscale along the front with perhaps a bowing segment as it moves
through south-central Oklahoma later this evening. Very large
hail, damaging winds, and an isolated tornado are possible.

Thompson

&&

.LONG TERM...
(Saturday night through next Thursday)
Issued at 159 PM CDT Fri Apr 23 2021

Gusty winds Saturday morning behind the front will decrease through
the day as the surface ridge quickly builds over the area. The
airmass behind the front will not offer much change in temperatures,
as highs reach near 70 to the mid 70s across southwest OK by
Saturday afternoon. As the surface high slides eastward and upper
ridging builds overhead temperatures will warm further Sunday. Lee
cyclogenesis east of the Rockies will tighten the pressure gradient
over the area during the day, which will lead to a period of gusty
south winds, especially across western OK. This will increase fire
weather concerns on Sunday across extreme western portions of the
area to the west of a dryline, with similar conditions possible
Monday and Tuesday (depending on dryline positioning this may end up
confined to the TX/OK panhandles).

A deep trough approaches by Tuesday, with models continuing to
disagree on timing and amplitude of the trough. Moisture return no
longer looks to be a question as models advertise now agree on a
deeper, slower trough with more meridional flow. There are still so
me timing differences, however, with the GFS faster and further east
with the dryline on Tuesday (central OK) and the ECM slower and
further west (western OK or the TX panhandle). Given such a deep
trough the slower solution seems more likely (and appears to be the
trend in the models the last few days). The slowing of the trough
may linger the severe risk into Wednesday for at least eastern
portions of the area and may also increase the risk for flooding
concerns. Bottom line, the ingredients still appear favorable for
severe weather in our area Tuesday (and perhaps Wednesday as well),
but details still remain unclear on exactly where and when the
greatest threat will occur.

The front should clear the area by Wednesday night, but the upper
trough will linger overhead through the end of the week. This should
keep temperatures cooler than average to end the week with dry
conditions.

Ware

&&

.AVIATION...
(00Z TAFS)
Issued at 618 PM CDT Fri Apr 23 2021

Mostly IFR/MVFR conditions are expected this evening through the
overnight hours. Showers and thunderstorms are expected to impact
all TAF sites this evening and into the overnight. The primary
threats with these thunderstorms are large hail and wind gusts up
to 80 mph. A cold front is expected to move through the area this
evening, with winds shifting back to the the ENE tomorrow at the
end of the period.

&&

.UPPER AIR...
Issued at 618 PM CDT Fri Apr 23 2021

An Upper Air flight is planned for 00Z on 04/24..

&&

.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK  52  69  48  79 /  90  10   0   0
Hobart OK         49  72  47  85 /  90   0   0   0
Wichita Falls TX  53  73  49  86 /  70   0   0   0
Gage OK           43  71  48  88 /  40   0   0   0
Ponca City OK     51  69  46  78 / 100  10   0   0
Durant OK         55  73  49  80 /  90  10   0   0

&&

.OUN WATCHES/WARNINGS/ADVISORIES...
OK...None.
TX...None.
&&

SHORT TERM...01
LONG TERM....08
AVIATION...13

Hazardous weather outlook, Apr 23, 2:30 PM CDT, 6 hours 42 minutes before

Hazardous Weather Outlook
National Weather Service Norman OK
230 PM CDT Fri Apr 23 2021

OKZ004>048-050>052-TXZ083>090-241930-
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-
230 PM CDT Fri Apr 23 2021

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

.DAY ONE...Today and Tonight...

.Thunderstorms...
Severe thunderstorms are expected this afternoon and evening
across Oklahoma and northern Texas. Severe thunderstorms this
afternoon and evening across western north Texas and southwestern
OK may contain hail up to the size of baseballs, damaging wind
gusts around 70 mph, and an isolated tornado are possible.

During the evening hours, thunderstorms are expected to become
more numerous across central and south central Oklahoma. These
storms will mainly pose a risk of large hail and damaging winds.
As storms move east of Interstate 35 this evening, the hail threat
is expected to decrease some, but damaging winds will still be a
concern.

Heavy rainfall and localized flooding are also a concern,
especially across central and southern OK as several rounds of
storms are expected this evening.

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

.Thunderstorms...
Severe thunderstorms will be possible next Tuesday across most of
the region.

.Fire Weather...
Elevated to Near Critical fire weather conditions are possible
across western Oklahoma and western north Texas Sunday through
Tuesday.

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 23, 8:55 PM CDT, 17 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
855 PM CDT FRI APR 23 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0851 PM     HAIL             2 NE LAKESIDE CITY      33.85N 98.51W
04/23/2021  E1.00 INCH       WICHITA            TX   PUBLIC

            REPORT FROM MPING: QUARTER (1.00 IN.).

&&

Local storm report, Apr 23, 8:56 PM CDT, 16 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
856 PM CDT FRI APR 23 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0851 PM     HAIL             3 SW WICHITA FALLS      33.88N 98.53W
04/23/2021  E1.25 INCH       WICHITA            TX   TRAINED SPOTTER

&&

Local storm report, Apr 23, 8:58 PM CDT, 14 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
858 PM CDT FRI APR 23 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0856 PM     TSTM WND GST     1 NW MEERS              34.79N 98.59W
04/23/2021  M60 MPH          COMANCHE           OK   EMERGENCY MNGR

&&

Special weather statement, Apr 23, 8:59 PM CDT, 13 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE Norman OK
859 PM CDT Fri Apr 23 2021

OKZ028-040-041-046-240230-
Carter OK-Garvin OK-McClain OK-Murray OK-
859 PM CDT Fri Apr 23 2021

...SIGNIFICANT WEATHER ADVISORY FOR northwestern Carter...Garvin...
southwestern McClain and northwestern Murray Counties Until 930 PM
CDT...

AT 856 PM CDT, a strong thunderstorm was located 4 miles west of
Maysville, moving east at 40 MPH.

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

LAT...LON 3444 9756 3495 9757 3493 9720 3452 9700
TIME...MOT...LOC 0156Z 255DEG 34KT 3483 9749

JP

Local storm report, Apr 23, 9:02 PM CDT, 10 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
902 PM CDT FRI APR 23 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0859 PM     HAIL             5 SSW LAKESIDE CITY     33.76N 98.58W
04/23/2021  E3.00 INCH       ARCHER             TX   TRAINED SPOTTER

&&

Local storm report, Apr 23, 9:12 PM CDT, 0 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
912 PM CDT FRI APR 23 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0856 PM     HAIL             LAKESIDE CITY           33.83N 98.55W
04/23/2021  M3.00 INCH       ARCHER             TX   EMERGENCY MNGR

&&

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 23, 7:01 PM CDT	Severe Thunderstorm Warning	OUN	Wichita, Wilbarger	44 min
Apr 23, 7:06 PM CDT	Severe Thunderstorm Warning	OUN	Hardeman	39 min
Apr 23, 7:32 PM CDT	Severe Thunderstorm Warning	OUN	Archer, Baylor, Wichita, Wilbarger	43 min
Apr 23, 7:44 PM CDT	Severe Thunderstorm Warning	OUN	Archer, Wichita	46 min
Apr 23, 7:52 PM CDT	Severe Thunderstorm Warning	OUN	Clay, Wichita	37 min
Apr 23, 8:14 PM CDT	Severe Thunderstorm Warning	OUN	Archer, Wichita	46 min
Apr 23, 8:18 PM CDT	Severe Thunderstorm Warning	OUN	Clay, Wichita	42 min
Apr 23, 8:33 PM CDT	Severe Thunderstorm Warning	OUN	Archer, Clay, Wichita	42 min
Apr 23, 8:44 PM CDT	Severe Thunderstorm Warning	OUN	Clay	31 min
Apr 23, 8:46 PM CDT	Areal Flood Advisory	OUN	Wichita	3 hr
Apr 23, 9:02 PM CDT	Severe Thunderstorm Warning	OUN	Archer, Clay	43 min
Apr 23, 9:27 PM CDT	Severe Thunderstorm Warning	OUN	Archer, Clay	48 min
Apr 23, 9:44 PM CDT	Severe Thunderstorm Warning	OUN	Clay	46 min
Apr 23, 7:15 PM CDT	Special Weather Statement	OUN	Garfield	30 min
Apr 23, 7:24 PM CDT	Special Weather Statement	OUN	Comanche	36 min
Apr 23, 8:00 PM CDT	Special Weather Statement	OUN	Grady	30 min
Apr 23, 8:04 PM CDT	Special Weather Statement	OUN	Stephens	26 min
Apr 23, 8:24 PM CDT	Severe Thunderstorm Warning	OUN	Garvin, Grady, McClain, Stephens	51 min
Apr 23, 8:36 PM CDT	Severe Thunderstorm Warning	OUN	Jefferson, Stephens	39 min
Apr 23, 8:53 PM CDT	Special Weather Statement	OUN	Cleveland, McClain	37 min
Apr 23, 8:59 PM CDT	Special Weather Statement	OUN	Garvin	31 min
Apr 23, 9:29 PM CDT	Special Weather Statement	OUN	Cleveland, Garvin, Pottawatomie	31 min
Apr 23, 10:00 PM CDT	Special Weather Statement	OUN	Carter, Murray, Pontotoc, Pottawatomie, Seminole	30 min
Apr 23, 10:29 PM CDT	Special Weather Statement	OUN	Coal, Hughes, Johnston, Love, Marshall, Pontotoc and 1 more	31 min
Apr 23, 11:00 PM CDT	Special Weather Statement	OUN	Atoka, Bryan, Coal, Hughes, Marshall, Seminole	30 min
Apr 23, 11:08 PM CDT	Areal Flood Advisory	OUN	Atoka, Bryan	3 hr

Nearby

Severe Thunderstorm Warnings in Oklahoma, 2021 Severe Thunderstorm Warnings in Texas, 2021 Every severe thunderstorm 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.