Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 490, NWS Norman, OK

May 28, 2017Garvin County, McClain County, Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at May 28, 2017, 1:15 AM CDT for Garvin County, McClain County, Oklahoma. It was in force for 45 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 28, 2017, 1:15 AM CDT (06:15 UTC)
Expired: May 28, 2017, 2:00 AM CDT
In force: 45 min
Issued by: NWS Norman, OK
Area: Storm-based polygon
Hail: 1.25 in
Wind: 60.0 mph

Counties Garvin County, OK, McClain County, OK

The radar

The Norman radar (KTLX), 54 km from the middle of the area, began a volume at 06:14 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
May 27, 4:01 PM CDT	Tornado Watch	SPC	10 hr

The nearest sounding before it

Norman, OK (KOUN), launched 00:00Z, 6.3 hours before the alert went out and 40 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: 5174 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 1475 m above ground
0-6 km bulk shear: 56 kt
0-1 km storm-relative helicity: 91 m²/s²
0-3 km storm-relative helicity: 119 m²/s²
Significant tornado parameter: 1.2
Supercell composite: 8.1

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 28, 12:35 AM CDT, 40 minutes earlier.

Area forecast discussion, May 28, 12:35 AM CDT, 40 minutes before

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Hazardous weather outlook, May 27, 12:38 PM CDT, 12 hours 37 minutes before

Hazardous Weather Outlook...UPDATED
National Weather Service Norman OK
1238 PM CDT Sat May 27 2017

OKZ004>048-050>052-TXZ083>090-281230-
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-
1238 PM CDT Sat May 27 2017

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

.DAY ONE...This Afternoon and Tonight...

.Thunderstorms...
There is a risk of severe storms across portions of Oklahoma and
north Texas.

Location...
An enhanced risk is along and east of a line from Ponca City to
Yukon to Ardmore Oklahoma. A slight risk resides east of a line
from Wakita to east of Hinton to Lawton to Wichita Falls Texas,
up to the enhanced risk.

Timing...
The most likely time for severe storms will be from 4 PM to 4 AM.

Impacts...
Large, damaging hail, up to the size of softballs, and damaging
winds to 80 mph will be the primary concerns. There is a medium
risk for tornadoes with the early, isolated, activity that may
develop along the dry line in south central Oklahoma.

Discussion...
A dry line will continue to develop across portions of central
and southwest Oklahoma and western north Texas. Enough lift may
exist to overcome a strong cap leading to isolated to scattered
storms developing near the dry line late this afternoon and
evening. If these storms develop, they will likely become severe
with large, damaging, hail, possibly approaching the size of
Softballs, and damaging winds up to 70 mph. There will also be a
low chance for tornadoes with these storms since they will be more
likely to stay discrete.

There is also a chance of storms this evening and overnight near
a cold front that will move across the area. These storms would be
more widespread and are expected to develop into one or more line
segments. Some of these storms could also become severe producing
large hail up to the size of golf balls and damaging wind gusts
to 80 mph. The potential for tornadoes will be lower with the
line of storms.

Thunderstorms will remain possible across parts of the area into
Sunday.

.SPOTTER AND EMERGENCY MANAGEMENT STATEMENT...

Storm spotter groups and emergency management personnel across the
risk areas should prepare for severe weather operations late this
afternoon into tonight.

.Heat...
Heat index values of 103 to 109 will be possible today across
portions of central and south central Oklahoma, and western north
Texas. If you are going to be outdoors, take steps to prevent heat
related illnesses.

.DAYS TWO THROUGH SEVEN...Sunday through Friday...

.Thunderstorms...
A few strong to severe storms will remain possible Sunday morning
in parts of south central and southeast Oklahoma, mainly southeast
of a line from Centrahoma to Ardmore Oklahoma.

Thunderstorm chances will return to parts of the area Monday night
and continue through the rest of next week.

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

Kurtz

In the hours before

Local storm report, May 28, 12:10 AM CDT, 1 hour 5 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
1210 AM CDT SUN MAY 28 2017

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

1100 PM     TSTM WND DMG     COALGATE                34.53N 96.22W
05/27/2017                   COAL               OK   EMERGENCY MNGR

            MULTIPLE TREES AND POWER LONES DOWN ON SOUTH SIDE OF
            COALGATE.

&&

DW

Local storm report, May 28, 12:15 AM CDT, 1 hour before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
1215 AM CDT SUN MAY 28 2017

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

1213 AM     HAIL             2 W ARDMORE             34.17N 97.17W
05/28/2017  E0.75 INCH       CARTER             OK   TRAINED SPOTTER

&&

TLINDLEY

Local storm report, May 28, 12:28 AM CDT, 47 minutes before

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Special weather statement, May 28, 12:47 AM CDT, 28 minutes before

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Local storm report, May 28, 1:06 AM CDT, 9 minutes before

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Special weather statement, May 28, 1:07 AM CDT, 8 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
May 27, 7:14 PM CDT	Special Weather Statement	OUN	Lincoln	46 min
May 27, 7:19 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Johnston, Murray	56 min
May 27, 7:25 PM CDT	Severe Thunderstorm Warning	OUN	Lincoln	41 min
May 27, 7:28 PM CDT	Special Weather Statement	OUN	Stephens	62 min
May 27, 7:35 PM CDT	Severe Thunderstorm Warning	OUN	Garvin, Pontotoc, Pottawatomie, Seminole	40 min
May 27, 7:36 PM CDT	Severe Thunderstorm Warning	OUN	Comanche, Cotton, Stephens	54 min
May 27, 7:41 PM CDT	Severe Thunderstorm Warning	OUN	Johnston, Murray, Pontotoc	49 min
May 27, 7:54 PM CDT	Tornado Warning	OUN	Johnston	36 min
May 27, 8:04 PM CDT	Severe Thunderstorm Warning	OUN	Grady	56 min
May 27, 8:09 PM CDT	Severe Thunderstorm Warning	OUN	Hughes, Pontotoc, Pottawatomie, Seminole	51 min
May 27, 8:12 PM CDT	Severe Thunderstorm Warning	OUN	Atoka, Coal, Johnston	48 min
May 27, 8:22 PM CDT	Severe Thunderstorm Warning	OUN	Garvin, Grady, Stephens	68 min
May 27, 8:29 PM CDT	Severe Thunderstorm Warning	OUN	Coal, Johnston, Pontotoc	24 min
May 27, 8:38 PM CDT	Severe Thunderstorm Warning	OUN	Garvin, McClain	49 min
May 27, 8:43 PM CDT	Severe Thunderstorm Warning	OUN	Pottawatomie, Seminole	48 min
May 27, 8:55 PM CDT	Severe Thunderstorm Warning	OUN	Atoka, Coal	50 min
May 27, 8:55 PM CDT	Tornado Warning	OUN	Carter, Garvin, Murray, Stephens	35 min
May 27, 9:01 PM CDT	Severe Thunderstorm Warning	OUN	Atoka, Coal	44 min
May 27, 9:06 PM CDT	Severe Thunderstorm Warning	OUN	Garvin, McClain, Pontotoc, Pottawatomie, Seminole	24 min
May 27, 9:07 PM CDT	Special Weather Statement	OUN	Okfuskee	38 min
May 27, 9:11 PM CDT	Severe Thunderstorm Warning	OUN	Cleveland, McClain, Pottawatomie	40 min
May 27, 9:20 PM CDT	Severe Thunderstorm Warning	OUN	Garvin, Stephens	40 min
May 27, 9:24 PM CDT	Severe Thunderstorm Warning	OUN	Lincoln, Pottawatomie, Seminole	51 min
May 27, 9:24 PM CDT	Tornado Warning	OUN	Carter, Garvin, Murray	36 min
May 27, 9:28 PM CDT	Severe Thunderstorm Warning	OUN	McClain, Pontotoc, Pottawatomie, Seminole	47 min
May 27, 9:37 PM CDT	Severe Thunderstorm Warning	OUN	Garvin, Murray	68 min
May 27, 9:40 PM CDT	Severe Thunderstorm Warning	OUN	Atoka, Coal	55 min
May 27, 9:46 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Garvin, Murray, Stephens	59 min
May 27, 9:47 PM CDT	Areal Flood Advisory	OUN	Carter, Garvin, Johnston, Murray, Stephens	3 hr
May 27, 9:47 PM CDT	Tornado Warning	OUN	Murray	28 min
May 27, 9:49 PM CDT	Special Weather Statement	OUN	Hughes, Pottawatomie, Seminole	56 min
May 27, 9:53 PM CDT	Severe Thunderstorm Warning	OUN	Ellis, Harper	52 min
May 27, 10:09 PM CDT	Flash Flood Warning	OUN	Carter, Garvin, Johnston, Murray, Pontotoc, Stephens	4 hr
May 27, 10:09 PM CDT	Tornado Warning	OUN	Carter, Murray	36 min
May 27, 10:13 PM CDT	Severe Thunderstorm Warning	OUN	Lincoln, Pottawatomie, Seminole	47 min
May 27, 10:16 PM CDT	Flash Flood Warning	OUN	Atoka, Coal	4 hr
May 27, 10:22 PM CDT	Flash Flood Warning	OUN	Lincoln, Pottawatomie	4 hr
May 27, 10:24 PM CDT	Severe Thunderstorm Warning	OUN	Coal, Johnston, Murray, Pontotoc	66 min
May 27, 10:26 PM CDT	Special Weather Statement	OUN	Stephens	34 min
May 27, 10:26 PM CDT	Severe Thunderstorm Warning	OUN	Dewey, Ellis, Major, Woodward	49 min
May 27, 10:32 PM CDT	Tornado Warning	OUN	Carter, Johnston, Murray	43 min
May 27, 10:39 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Garvin, Jefferson, Johnston, Murray, Stephens	51 min
May 27, 10:50 PM CDT	Severe Thunderstorm Warning	OUN	Atoka, Coal, Hughes, Johnston, Pontotoc	70 min
May 27, 11:04 PM CDT	Tornado Warning	OUN	Jefferson, Stephens	26 min
May 27, 11:14 PM CDT	Severe Thunderstorm Warning	OUN	Blaine, Dewey, Harper, Major, Woods, Woodward	46 min
May 27, 11:17 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Coal, Cotton, Garvin, Jefferson, Johnston and 3 more	73 min
May 27, 11:24 PM CDT	Tornado Warning	OUN	Carter, Jefferson	36 min
May 27, 11:46 PM CDT	Severe Thunderstorm Warning	OUN	Alfalfa, Blaine, Garfield, Kingfisher, Major, Woods	44 min
May 27, 11:48 PM CDT	Tornado Warning	OUN	Carter	27 min
May 27, 11:50 PM CDT	Flash Flood Warning	OUN	Atoka, Coal, Johnston, Pontotoc	4 hr
May 28, 12:09 AM CDT	Severe Thunderstorm Warning	OUN	Carter, Jefferson, Love	81 min
May 28, 12:13 AM CDT	Flash Flood Warning	OUN	Carter, Jefferson, Stephens	5 hr
May 28, 12:18 AM CDT	Tornado Warning	OUN	Jefferson, Love	27 min
May 28, 12:19 AM CDT	Severe Thunderstorm Warning	OUN	Garfield, Kingfisher, Major	26 min
May 28, 12:25 AM CDT	Severe Thunderstorm Warning	OUN	Atoka, Bryan, Carter, Coal, Johnston, Love and 1 more	65 min
May 28, 12:39 AM CDT	Tornado Warning	OUN	Love	36 min
May 28, 12:47 AM CDT	Special Weather Statement	OUN	Garfield, Kingfisher	28 min
May 28, 1:04 AM CDT	Severe Thunderstorm Warning	OUN	Bryan, Love, Marshall	56 min
May 28, 1:07 AM CDT	Special Weather Statement	OUN	McClain	23 min
May 28, 1:10 AM CDT	Areal Flood Advisory	OUN	Carter, Jefferson, Love	4 hr
May 28, 1:27 AM CDT	Special Weather Statement	OUN	Pottawatomie	33 min
May 28, 1:57 AM CDT	Severe Thunderstorm Warning	OUN	Garvin, Murray, Pontotoc	18 min
May 28, 1:58 AM CDT	Severe Thunderstorm Warning	OUN	Cleveland, Garvin, McClain, Pottawatomie	32 min
May 28, 2:09 AM CDT	Special Weather Statement	OUN	Bryan	36 min
May 28, 3:51 AM CDT	Special Weather Statement	OUN	Love	24 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.