Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 211, NWS Norman, OK

May 4, 20207 counties in Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at May 4, 2020, 6:08 PM CDT for 7 counties in Oklahoma. It was in force for 52 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
May 4, 2020, 6:08 PM CDT (23:08 UTC)
Expired
May 4, 2020, 7:00 PM CDT
In force
52 min
Issued by
NWS Norman, OK
Area
Storm-based polygon
Hail
2.0 in
Wind
60.0 mph

Counties Cleveland County, OK, Garvin County, OK, McClain County, OK, Murray County, OK, Pontotoc County, OK, Pottawatomie County, OK, Seminole County, OK

The radar

The Norman radar (KTLX), 49 km from the middle of the area, began a volume at 23:07 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.

IssuedProductOfficeLasted
May 4, 2:32 PM CDTTornado WatchSPC9 hr
May 4, 4:38 PM CDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Norman, OK (KOUN), launched 12:00Z, 11.1 hours before the alert went out and 45 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-pSkew-T log-p diagram, Norman, OK at 12:00Z on 2020-05-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1672 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Norman, OK at 12:00Z on 2020-05-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 431 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
1672 J/kg
Mixed-layer CIN
-406 J/kg
Mixed-layer LCL
989 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
431 m²/s²
0-3 km storm-relative helicity
411 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.1

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 May 4, 3:12 PM CDT, 2 hours 56 minutes earlier.

Area forecast discussion, May 4, 3:12 PM CDT, 2 hours 56 minutes before
Area Forecast Discussion
National Weather Service Norman OK
312 PM CDT Mon May 4 2020

...New SHORT TERM, LONG TERM...

.SHORT TERM...
(This evening through Tuesday)
Issued at 223 PM CDT Mon May 4 2020

As of 19Z, the prefrontal trough extended from Osage - Canadian -
Beckham counties with northwesterly winds behind the axis. The
cold front was located near the OK/KS border with temperatures in
the 60s behind the front. The front is expected to quickly
progress south across Oklahoma and western north Texas this
evening and overnight. The 19Z sounding shows a strong cap over
the OKC area, and is unlikely to break unless sufficient
ascent/cooling arrives. A tornado watch has been issued for
Seminole, Hughes, Pontotoc, and Coal counties until 10PM. Latest
trends indicate convective initiation will likely be
east/southeast of the OKC metro by 7PM. The primary hazards for
our CWA will be large hail and damaging winds, although, a tornado
cannot be ruled out.

Northerly winds and strong cold air advection will keep
temperatures much cooler tomorrow - maximum temperatures will be
in the 70s and near 80 degrees (SW Oklahoma and western north TX).

Thompson

&&

.LONG TERM...
(Tuesday night through next Sunday)
Issued at 223 PM CDT Mon May 4 2020

Surface high builds over the plains and provides for mild
conditions on Tuesday and Wednesday. A surface cyclone develops on
Thursday in advance of a midlevel shortwave, though models
continue to show a considerable difference on the placement of
the low through 00Z Friday. Daytime high temperatures for Thursday
have been lowered as the trend is for the surface low to pass
south of the TX/OK border, placing most of our area on the cool
side. Chances for showers/thunderstorms return on Thursday and
again Sunday afternoon/evening.

Below average temperatures are still expected Friday through early
next week.

Thompson

&&

.AVIATION...
(18Z TAFS)
Issued at 1235 PM CDT Mon May 4 2020

A period of post-frontal MVFR cigs will be possible at KPNC this
afternoon, otherwise VFR conditions expected to prevail. TSRA
will develop near a fast moving cold front late this afternoon and
we currently expect this convection to be east and south of
terminals. Gusty southwest winds will become north and northeast
as front moves by, with gusts 20 to 30 KT common.

&&

.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK  56  74  52  80 /  10   0   0   0
Hobart OK         56  77  50  82 /   0   0   0   0
Wichita Falls TX  61  79  52  83 /  10   0   0   0
Gage OK           50  75  50  82 /   0   0   0   0
Ponca City OK     52  74  50  78 /   0   0   0   0
Durant OK         61  76  51  80 /  60  10   0   0

&&

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

SHORT TERM...01
LONG TERM....01
AVIATION...11
Hazardous weather outlook, May 4, 12:01 PM CDT, 6 hours 7 minutes before
Hazardous Weather Outlook
National Weather Service Norman OK
1201 PM CDT Mon May 4 2020

OKZ004>048-050>052-TXZ083>090-051015-
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-
1201 PM CDT Mon May 4 2020

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

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

There is a Slight Risk for severe thunderstorms today generally
east of a line from Ponca City to Oklahoma City and Duncan. Within
the slight risk area is an Enhanced Risk which covers parts of
northeast into southeast Oklahoma, including the cities of
Seminole, Holdenville, Coalgate, and Atoka.

The most likely time for severe storms today will be between 4 pm
and 11 pm. Thunderstorms are expected to develop along a cold
front during the late afternoon hours across central and
northeast Oklahoma, then spread south through the evening as the
cold front advances southward.

The primary hazards are very large hail up to the size of
baseballs and damaging winds, but there is also some potential for
a tornado as well. The tornado risk will be highest in the
Enhanced Risk area through early evening.

.Fire Weather...
Elevated to Near Critical fire weather conditions are expected
across southwest Oklahoma and western north Texas. Triple digit
heat will combine with a moderate wind and very low humidity to
elevate conditions.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday...

.Thunderstorms...
Storm chances return Wednesday night through Thursday night.
Strong to severe thunderstorms will be possible late Thursday into
early Friday.

.Fire Weather...
Elevated fire weather conditions are expected to develop
across western Oklahoma and western north Texas Tuesday
afternoon.

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, May 4, 5:38 PM CDT, 30 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
538 PM CDT MON MAY 4 2020

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

0515 PM     HAIL             5 NE NOBLE              35.19N 97.34W
05/04/2020  E2.50 INCH       CLEVELAND          OK   BROADCAST MEDIA

            TWITTER PIC.

&&

PW
Local storm report, May 4, 5:41 PM CDT, 27 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
541 PM CDT MON MAY 4 2020

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

0535 PM     HAIL             4 ENE SLAUGHTERVILLE    35.12N 97.27W
05/04/2020  M2.75 INCH       CLEVELAND          OK   PUBLIC

&&

PW
Local storm report, May 4, 5:43 PM CDT, 25 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
543 PM CDT MON MAY 4 2020

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

0538 PM     HAIL             ETOWAH                  35.13N 97.17W
05/04/2020  M2.50 INCH       CLEVELAND          OK   BROADCAST MEDIA

&&
Local storm report, May 4, 5:48 PM CDT, 20 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
548 PM CDT MON MAY 4 2020

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

0514 PM     HAIL             5 SW LAKE THUNDERBIRD   35.19N 97.30W
05/04/2020  E3.00 INCH       CLEVELAND          OK   BROADCAST MEDIA

            MEASUREMENT IN TWITTER PIC. TIME ESTIMATED.

&&

PW
Local storm report, May 4, 5:55 PM CDT, 13 minutes before
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Local storm report, May 4, 6:03 PM CDT, 5 minutes before
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    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
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The office that day

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

IssuedProductOfficeCountiesLasted
May 4, 4:31 PM CDTSpecial Weather StatementOUNCleveland29 min
May 4, 4:38 PM CDTSevere Thunderstorm WarningOUNCleveland, Pottawatomie37 min
May 4, 4:44 PM CDTSevere Thunderstorm WarningOUNCleveland31 min
May 4, 4:50 PM CDTSevere Thunderstorm WarningOUNLincoln40 min
May 4, 5:07 PM CDTSevere Thunderstorm WarningOUNCleveland, Pottawatomie53 min
May 4, 5:26 PM CDTSevere Thunderstorm WarningOUNCleveland, McClain, Pottawatomie49 min
May 4, 5:36 PM CDTSevere Thunderstorm WarningOUNPottawatomie, Seminole39 min
May 4, 5:54 PM CDTTornado WarningOUNCleveland, Garvin, McClain, Pottawatomie36 min
May 4, 6:21 PM CDTSevere Thunderstorm WarningOUNGarvin, McClain39 min
May 4, 6:51 PM CDTSevere Thunderstorm WarningOUNCoal, Hughes, Pontotoc, Seminole24 min
May 4, 6:57 PM CDTSevere Thunderstorm WarningOUNCarter, Garvin, McClain, Murray, Pontotoc48 min

Nearby

Severe Thunderstorm Warnings in Oklahoma, 2020Every 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.