Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 381, NWS Norman, OK

May 18, 2017Cotton County, Tillman County, Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at May 18, 2017, 8:37 PM CDT for Cotton County, Tillman County, Oklahoma. It was in force for 53 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 18, 2017, 8:37 PM CDT (01:37 UTC)
Expired: May 18, 2017, 9:30 PM CDT
In force: 53 min
Issued by: NWS Norman, OK
Area: Storm-based polygon
Hail: 1.75 in
Wind: 60.0 mph

Counties Cotton County, OK, Tillman County, OK

The radar

The Altus AFB radar (KFDR), 30 km from the middle of the area, began a volume at 01:41 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 18, 7:47 PM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Fort Worth, TX (KFWD), launched 00:00Z, 1.6 hours before the alert went out and 209 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: 1519 J/kg
Mixed-layer CIN: -36 J/kg
Mixed-layer LCL: 1729 m above ground
0-6 km bulk shear: 50 kt
0-1 km storm-relative helicity: 154 m²/s²
0-3 km storm-relative helicity: 211 m²/s²
Significant tornado parameter: 0.5
Supercell composite: 16.4

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 18, 6:55 PM CDT, 1 hour 42 minutes earlier.

Area forecast discussion, May 18, 6:55 PM CDT, 1 hour 42 minutes before

Area Forecast Discussion
National Weather Service Norman OK
655 PM CDT Thu May 18 2017

.UPDATE...
Mesoscale update is below.

&&

.DISCUSSION...
Severe thunderstorms will continue this evening mainly southeast
of I-44 and north of I-40.

Tornadoes remain possible this evening mainly with the ongoing
storms near and southeast of a Seymour Texas to Wichita Falls to
Walters to Purcell to Shawnee line where the air is most unstable
with MLCAPE 2000-4000 J/kg. Northwest of this line, the tornado
threat is lower due to cooler and more stable air from earlier
storms. Believe the tornado threat will slowly decrease after 8 pm
and be very low after midnight across the entire area.

Think storms will continue to move east over the next several
hours and affect locations mentioned in the top sentence. Large
hail and damaging winds will be possible with any storm. Severe
potential should decrease in most locations after 10 pm this
evening with the loss of daytime heating.

Heavy rainfall is another concern tonight. The complex of storms
from Wichita Falls to Walters will slowly move east over the next
few hours and produce very heavy rainfall as well as possible
localized flooding. There is some potential that new elevated storms,
mainly below severe limits, form later tonight somewhere across
the western two thirds of Oklahoma and western north Texas.
Pinpointing where and when this development occurs remain very
challenging.

Aviation discussion for the 00 UTC TAFs is below.

MBS

&&

.AVIATION...
Have low confidence in the TAFs.

Pinpointing when and where TSRA occurs remains very challenging.
Only kept mention before 03 UTC at some sites, mainly near KSPS,
KLAW, KOKC, KOUN, and KPNC. After 03 UTC, ISO-NUM TSRA may occur
across the area, but did not mention in the TAFs due to much
uncertainty on when and where TSRA occurs.

Generally, VFR conditions are forecast to become MVFR at most
sites 06-12 UTC. IFR conditions are possible as well, but only
mentioned these conditions near KWWR and KGAG where confidence of
occurrence is moderate 11-15 UTC. A slow improvement in conditions
can be expected after 15 UTC.

MBS

&&

.OUN WATCHES/WARNINGS/ADVISORIES...
OK...Flood Watch through Saturday morning for OKZ005>048-050>052.

TX...Flood Watch through Saturday morning for TXZ083>090.

&&

04/04/17

Hazardous weather outlook, May 18, 8:28 PM CDT, 9 minutes before

Hazardous Weather Outlook...UPDATED
National Weather Service Norman OK
828 PM CDT Thu May 18 2017

OKZ004>048-050>052-TXZ083>090-200130-
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-
828 PM CDT Thu May 18 2017

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 an Enhanced Risk for severe thunderstorms this evening
in parts of Oklahoma and western north Texas.

Location...
The Enhanced Risk area is east of a Seymour, Texas to Lawton to
Watonga to Cherokee line. Slight and Marginal Risk areas surround
the Enhanced Risk area across western Oklahoma and far western
north Texas.

Timing...
Mainly before midnight tonight.

Impacts...
Hail up to golf ball size...
Damaging winds 70 to 80 mph...
Tornadoes...

Discussion...
A line of showers and thunderstorms will continue to affect parts
of central and southern Oklahoma and western north Texas through
at least the evening hours. Additional isolated to scattered
storms will continue to affect northern Oklahoma this evening.
Due to sufficient shear, moisture, and instability, these storms
have the potential to produce large hail and damaging winds.

A low tornado potential will continue across parts of western
north Texas and southern Oklahoma before midnight tonight where
the air remains most unstable. Tornado potential is expected to
decrease throughout the night tonight.

After midnight tonight, thunderstorms may continue across parts
of the area, though most storms are expected to remain below
severe limits as instability decreases.

.SPOTTER AND EMERGENCY MANAGEMENT STATEMENT...
Storm spotter groups and emergency management personnel across
western and central Oklahoma and adjacent parts of north Texas
should prepare for severe weather operations through midnight
tonight.

.Heavy Rainfall...
Locally heavy rainfall and flooding may occur with storms
through tonight, especially near and southeast of I-44.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday...

.Thunderstorms...
There is an Enhanced Risk for severe thunderstorms Friday and
Friday night when tornadoes, large hail, and damaging winds are
all possible.

Weak thunderstorms may continue on Saturday mainly southeast
of I-44.

Thunderstorm chances will return to the area late Sunday through
Tuesday across parts of the area. A few strong storms may be
possible late Sunday through Tuesday.

.Heavy Rainfall...
There is a potential for excessive rainfall tonight until
Saturday morning, particularly over portions of central into
southern Oklahoma and adjacent parts of western north Texas. If
you live in an area that is prone to flash flooding, pay attention
to the forecasts and warnings later this week.

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

MBS/BT

In the hours before

Local storm report, May 18, 8:06 PM CDT, 31 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
806 PM CDT THU MAY 18 2017

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

0800 PM     TSTM WND DMG     NORMAN                  35.22N 97.44W
05/18/2017                   CLEVELAND          OK   PUBLIC

            NUMEROUS TREE LIMBS DOWNED IN TOWN.

&&

JP

Local storm report, May 18, 8:17 PM CDT, 20 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
817 PM CDT THU MAY 18 2017

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

0815 PM     HAIL             LAKE KICKAPOO           33.65N 98.81W
05/18/2017  E1.00 INCH       ARCHER             TX   FIRE DEPT/RESCUE

&&

JP

Local storm report, May 18, 8:21 PM CDT, 16 minutes before

PRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE NORMAN OK
821 PM CDT THU MAY 18 2017

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

0754 PM     TSTM WND GST     3 S NORMAN              35.18N 97.44W
05/18/2017  M61 MPH          CLEVELAND          OK   OFFICIAL NWS OBS

            AT NATIONAL WEATHER CENTER ON OU CAMPUS.

&&

JP

Local storm report, May 18, 8:27 PM CDT, 10 minutes before

PRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE NORMAN OK
827 PM CDT THU MAY 18 2017

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

0810 PM     TSTM WND GST     1 N LAKE KICKAPOO       33.66N 98.81W
05/18/2017  M57 MPH          ARCHER             TX   MESONET

&&

JP

Local storm report, May 18, 8:32 PM CDT, 5 minutes before

PRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE NORMAN OK
832 PM CDT THU MAY 18 2017

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

0810 PM     TSTM WND GST     1 N RINGLING            34.20N 97.59W
05/18/2017  M57 MPH          JEFFERSON          OK   MESONET

&&

JP

Local storm report, May 18, 8:35 PM CDT, 2 minutes before

PRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE NORMAN OK
835 PM CDT THU MAY 18 2017

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

0750 PM     TSTM WND DMG     1 NNE GOLDSBY           35.16N 97.47W
05/18/2017                   MCCLAIN            OK   EMERGENCY MNGR

            AIRCRAFT HANGERS DAMAGED AT DAVID PERRY
            AIRPORT.

&&

JP

The office that day

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

Issued	Product	Office	Counties	Lasted
May 18, 7:05 PM CDT	Areal Flood Advisory	OUN	Comanche, Cotton, Jefferson, Stephens, Tillman	3 hr
May 18, 7:13 PM CDT	Tornado Warning	OUN	Alfalfa, Woods	32 min
May 18, 7:15 PM CDT	Severe Thunderstorm Warning	OUN	Alfalfa, Major, Woods	45 min
May 18, 7:16 PM CDT	Severe Thunderstorm Warning	OUN	Cleveland, Oklahoma	29 min
May 18, 7:18 PM CDT	Special Weather Statement	OUN	Garfield	27 min
May 18, 7:24 PM CDT	Severe Thunderstorm Warning	OUN	Cleveland, McClain, Oklahoma	51 min
May 18, 7:27 PM CDT	Severe Thunderstorm Warning	OUN	Lincoln	33 min
May 18, 7:34 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Cotton, Garvin, Grady, Jefferson, Murray and 2 more	41 min
May 18, 7:40 PM CDT	Severe Thunderstorm Warning	OUN	Alfalfa, Grant	65 min
May 18, 7:43 PM CDT	Severe Thunderstorm Warning	OUN	Cleveland, Lincoln, Oklahoma, Pottawatomie	47 min
May 18, 7:49 PM CDT	Severe Thunderstorm Warning	OUN	Cleveland, McClain	26 min
May 18, 7:55 PM CDT	Severe Thunderstorm Warning	OUN	Alfalfa, Garfield, Grant, Major	50 min
May 18, 8:00 PM CDT	Areal Flood Advisory	OUN	Cleveland, McClain, Pottawatomie	3 hr
May 18, 8:12 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Garvin, Grady, Jefferson, Love, Murray and 2 more	48 min
May 18, 8:16 PM CDT	Severe Thunderstorm Warning	OUN	Cleveland, McClain	44 min
May 18, 8:19 PM CDT	Flash Flood Warning	OUN	Cotton, Jefferson, Stephens	3 hr
May 18, 8:24 PM CDT	Severe Thunderstorm Warning	OUN	Pottawatomie	51 min
May 18, 8:33 PM CDT	Severe Thunderstorm Warning	OUN	Lincoln	42 min
May 18, 8:45 PM CDT	Special Weather Statement	OUN	Grant	30 min
May 18, 8:45 PM CDT	Severe Thunderstorm Warning	OUN	Cleveland, Oklahoma, Pottawatomie	30 min
May 18, 8:53 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Coal, Garvin, Hughes, Johnston, Murray and 1 more	52 min
May 18, 8:56 PM CDT	Special Weather Statement	OUN	Alfalfa	49 min
May 18, 8:58 PM CDT	Special Weather Statement	OUN	Lincoln, Pottawatomie, Seminole	47 min
May 18, 9:08 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Jefferson	52 min
May 18, 9:11 PM CDT	Areal Flood Advisory	OUN	Carter, Murray	3 hr
May 18, 9:14 PM CDT	Severe Thunderstorm Warning	OUN	Hughes, Seminole	46 min
May 18, 9:17 PM CDT	Severe Thunderstorm Warning	OUN	Cotton, Jefferson, Stephens	43 min
May 18, 9:33 PM CDT	Severe Thunderstorm Warning	OUN	Atoka, Coal, Hughes, Pontotoc	27 min
May 18, 9:39 PM CDT	Special Weather Statement	OUN	Grant	36 min
May 18, 9:40 PM CDT	Tornado Warning	OUN	Jefferson	20 min
May 18, 9:48 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Coal, Johnston, Marshall, Murray, Pontotoc	42 min
May 18, 9:51 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Jefferson, Love	39 min
May 18, 9:55 PM CDT	Severe Thunderstorm Warning	OUN	Atoka, Coal, Hughes	35 min
May 18, 9:59 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Garvin, Stephens	46 min
May 18, 10:14 PM CDT	Areal Flood Advisory	OUN	Carter, Coal, Hughes, Johnston, Murray, Pontotoc	3 hr
May 18, 10:21 PM CDT	Special Weather Statement	OUN	Grant	24 min
May 18, 10:26 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Johnston, Murray	49 min
May 18, 10:40 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Love	50 min
May 18, 10:50 PM CDT	Severe Thunderstorm Warning	OUN	Atoka, Coal, Johnston, Pontotoc	40 min
May 18, 10:54 PM CDT	Tornado Warning	OUN	Carter, Love	36 min
May 18, 11:06 PM CDT	Tornado Warning	OUN	Coal, Johnston, Pontotoc	11 min
May 18, 11:20 PM CDT	Tornado Warning	OUN	Love, Marshall	25 min
May 18, 11:26 PM CDT	Severe Thunderstorm Warning	OUN	Atoka, Coal, Johnston	49 min
May 18, 11:32 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Johnston, Marshall	43 min
May 18, 11:41 PM CDT	Tornado Warning	OUN	Johnston, Marshall	34 min
May 19, 12:04 AM CDT	Severe Thunderstorm Warning	OUN	Atoka, Coal, Johnston	23 min
May 19, 12:35 AM CDT	Special Weather Statement	OUN	Canadian	25 min
May 19, 1:05 AM CDT	Special Weather Statement	OUN	Canadian	25 min
May 19, 1:13 AM CDT	Severe Thunderstorm Warning	OUN	Canadian, Logan, Oklahoma	47 min
May 19, 1:55 AM CDT	Severe Thunderstorm Warning	OUN	Blaine, Caddo, Canadian, Kingfisher, Lincoln, Logan and 2 more	50 min
May 19, 2:16 AM CDT	River Flood Warning	OUN	Pottawatomie, Seminole	23 hr
May 19, 2:26 AM CDT	Severe Thunderstorm Warning	OUN	Blaine, Canadian, Kingfisher, Lincoln, Logan, Oklahoma and 1 more	49 min
May 19, 2:32 AM CDT	Areal Flood Advisory	OUN	Logan, Oklahoma	118 min
May 19, 3:15 AM CDT	Severe Thunderstorm Warning	OUN	Lincoln, Logan, Payne	45 min
May 19, 3:37 AM CDT	Areal Flood Advisory	OUN	Lincoln, Logan, Payne	113 min
May 19, 6:44 AM CDT	Special Weather Statement	OUN	Tillman	31 min
May 19, 6:57 AM CDT	Special Weather Statement	OUN	Tillman	33 min
May 19, 8:04 AM CDT	Special Weather Statement	OUN	Caddo	41 min
May 19, 8:31 AM CDT	Special Weather Statement	OUN	Canadian, Kingfisher	44 min
May 19, 8:51 AM CDT	Special Weather Statement	OUN	Jefferson	39 min
May 19, 9:22 AM CDT	Special Weather Statement	OUN	Comanche, Cotton, Tillman	38 min
May 19, 9:27 AM CDT	Special Weather Statement	OUN	Garfield, Kingfisher, Major	48 min
May 19, 9:30 AM CDT	Special Weather Statement	OUN	Carter, Garvin, Jefferson, Murray, Pontotoc	45 min
May 19, 9:45 AM CDT	Special Weather Statement	OUN	Cleveland, Oklahoma	30 min
May 19, 10:03 AM CDT	Special Weather Statement	OUN	Alfalfa, Garfield, Grant	42 min
May 19, 10:07 AM CDT	River Flood Warning	OUN	Major, Woods, Woodward	15 hr
May 19, 11:15 AM CDT	Special Weather Statement	OUN	Hughes	45 min
May 19, 11:19 AM CDT	Special Weather Statement	OUN	Cleveland, Oklahoma	26 min
May 19, 12:05 PM CDT	Special Weather Statement	OUN	Cotton	25 min
May 19, 12:44 PM CDT	Special Weather Statement	OUN	Garvin	46 min
May 19, 2:07 PM CDT	Special Weather Statement	OUN	Cotton, Jefferson	38 min
May 19, 2:53 PM CDT	Special Weather Statement	OUN	Cotton	67 min
May 19, 3:00 PM CDT	Severe Thunderstorm Warning	OUN	Jefferson, Love	45 min
May 19, 3:03 PM CDT	Severe Thunderstorm Warning	OUN	Tillman	42 min
May 19, 3:28 PM CDT	Special Weather Statement	OUN	Garvin	32 min
May 19, 3:36 PM CDT	Severe Thunderstorm Warning	OUN	Comanche, Cotton, Jefferson, Tillman	54 min
May 19, 3:39 PM CDT	Special Weather Statement	OUN	Cleveland	36 min
May 19, 3:56 PM CDT	Special Weather Statement	OUN	Carter	34 min
May 19, 4:03 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Garvin, Murray	42 min
May 19, 4:19 PM CDT	Severe Thunderstorm Warning	OUN	Lincoln, Pottawatomie, Seminole	23 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.