Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 335, NWS Norman, OK

May 18, 20174 counties in Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at May 18, 2017, 2:55 PM CDT for 4 counties in Oklahoma. It was in force for 50 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, 2:55 PM CDT (19:55 UTC)
Expired: May 18, 2017, 3:45 PM CDT
In force: 50 min
Issued by: NWS Norman, OK
Area: Storm-based polygon
Hail: 1.5 in
Wind: 60.0 mph

Counties Custer County, OK, Dewey County, OK, Ellis County, OK, Roger Mills County, OK

The radar

The Vance AFB radar (KVNX), 146 km from the middle of the area, began a volume at 19:57 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, 1:18 PM CDT	Tornado Watch PDS	SPC	7 hr

The nearest sounding before it

Norman, OK (KOUN), launched 12:00Z, 7.9 hours before the alert went out and 192 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: 1272 J/kg
Mixed-layer CIN: -210 J/kg
Mixed-layer LCL: 1122 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 231 m²/s²
0-3 km storm-relative helicity: 250 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.9

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.

NWS Norman, OK wrote its last area forecast discussion before this severe thunderstorm warning went out at May 18, 2:23 PM CDT, 32 minutes earlier.

Area forecast discussion, May 18, 2:23 PM CDT, 32 minutes before

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

.DISCUSSION...
Main focus was on the severe weather and heavy rain potential
through Saturday.

Now through 7 pm this evening, isolated to scattered discrete
supercells are expected to continue to move northeast across parts
of western north Texas, western Oklahoma, central Oklahoma, and
northern Oklahoma, mainly near and just southeast of a low level
cloud shield/differential heating boundary that extended from near
Clinton to Enid to Ponca City as of 215 pm. The Lawton, Oklahoma
City, and Stillwater areas could be affected by these dangerous
storms in the next few hours. These storms will continue to produce
giant hail, damaging winds, and tornadoes. Tornado potential will
only increase over the next few hours as low level shear increases.
The greatest potential for tornadoes may be shifting farther south
and east than previously forecast.

Across far northwestern Oklahoma now through 7 pm this evening,
additional discrete supercells may form with giant hail, tornadoes,
and damaging winds. Not sure that this activity will be more robust
compared to activity near the line mentioned due to more cloud cover
to limit destabilization.

Capping may be too strong for storm development south of a Knox
City, Texas to Wichita Falls to Ada line now through 7 pm this
evening.

Severe storms will remain possible this evening as they move
east. Models show the area of storm development in NW OK developing
down towards central OK as they move east tonight. In addition to
large hail, strong winds, and tornadoes possible, heavy rain that
could produce flash flooding in some locations will also be a
concern.

On Friday... Upper low and shortwave rotating around the low will
affect the region with a cold front moving across the area.
Widespread storms are expected to develop Friday afternoon and
continue into Friday night. Severe storms will be possible once
again. The potential for heavy rain and flash flooding will likely
be higher Friday than today across a larger area. 3-5 inches of
rain with locally higher amounts will be possible by Saturday
morning. With the heavy rain and flash flood potential, a Flood
Watch was issued earlier today for all but Harper county in NW OK.
It is in effect from 7 PM this evening through 7 AM Saturday. Models
show the rain shifting east and south of the area Saturday as the
front moves out of the area and the upper low lifts NE.

Shower and thunderstorm chances will return to the area Sunday
night and continue into Tuesday.

&&

.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK  68  77  55  71 /  70  70  90  20
Hobart OK         64  81  53  73 /  40  90  70  10
Wichita Falls TX  69  84  58  76 /  60  70  80  20
Gage OK           57  75  47  69 /  40  50  30   0
Ponca City OK     66  78  54  69 /  70  70  80  10
Durant OK         70  84  66  76 /  60  50  80  60

&&

.OUN WATCHES/WARNINGS/ADVISORIES...
OK...Flood Watch from 7 PM CDT this evening through Saturday morning
     for OKZ005>048-050>052.

TX...Flood Watch from 7 PM CDT this evening through Saturday morning
     for TXZ083>090.

&&

06/25

Hazardous weather outlook, May 18, 11:58 AM CDT, 2 hours 57 minutes before

Hazardous Weather Outlook...UPDATED
National Weather Service Norman OK
1158 AM CDT Thu May 18 2017

OKZ004>048-050>052-TXZ083>090-191100-
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-
1158 AM 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...This afternoon and tonight...

.Thunderstorms...
There is a high risk for severe thunderstorms this afternoon and
evening in parts of Oklahoma.

Location...
The high risk is over much of northwest Oklahoma, east of a
Buffalo to Leedey line and north of a Leedey to Kingfisher to
Blackwell line. Locations in the high risk area include
Woodward...Alva...Watonga...Enid...Medford...and Cherokee.
Moderate to enhanced risk areas surround the high risk area
across the rest of Oklahoma into western north Texas.

Timing...
Mainly 1 PM until 10 PM.

Impacts...
Tornadoes...possibly strong and long-tracked...
Hail up to softball size...
Damaging winds 70 to 80 mph...

Discussion...
A warm and very unstable airmass is in place across most of
Oklahoma, east of a dryline. As heating continues and an upper
level storm slowly approaches, severe storms are expected to
develop by early afternoon. Several models indicate the first
storms will form across southwest Oklahoma and western north
Texas.

Instability and deep layer shear will support supercell
thunderstorms which will have the potential to produce very large
hail, damaging winds, and some tornadoes. Storms may organize into
lines or clusters by late afternoon or this evening as they track
northeast. Storms should begin to weaken by late evening.

.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 this afternoon
and evening.

.Heavy Rainfall...
Locally heavy rainfall and flooding may occur with storms this
afternoon and tonight.

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

.Thunderstorms...
There is an enhanced risk for severe thunderstorms Friday when
tornadoes, large hail, and damaging winds are all possible.
Mainly dry weather is expected Sunday and Monday. Thunderstorm
chances will increase around Tuesday of next week.

.Heavy Rainfall...
There is a potential for excessive rainfall Friday until Saturday
morning, particularly over portions of central into southwest
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, 2:44 PM CDT, 11 minutes before

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

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

0220 PM     HAIL             9 W ELDORADO            34.48N 99.81W
05/18/2017  E2.75 INCH       JACKSON            OK   PUBLIC

&&

Local storm report, May 18, 2:46 PM CDT, 9 minutes before

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

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

0241 PM     HAIL             7 SW CROWELL            33.91N 99.81W
05/18/2017  E1.50 INCH       FOARD              TX   LAW ENFORCEMENT

&&

MBS

Local storm report, May 18, 2:48 PM CDT, 7 minutes before

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

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

0247 PM     HAIL             GRANITE                 34.96N 99.38W
05/18/2017  M1.75 INCH       GREER              OK   EMERGENCY MNGR

&&

MBS

Local storm report, May 18, 2:49 PM CDT, 6 minutes before

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

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

0240 PM     HAIL             SAYRE                   35.30N 99.64W
05/18/2017  E0.75 INCH       BECKHAM            OK   PUBLIC

&&

Local storm report, May 18, 2:50 PM CDT, 5 minutes before

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

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

0250 PM     HAIL             2 W GILLILAND           33.73N 99.73W
05/18/2017  E1.75 INCH       KNOX               TX   PUBLIC

&&

Local storm report, May 18, 2:54 PM CDT, 1 minute before

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

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

0240 PM     HAIL             8 WNW TRUSCOTT          33.80N 99.95W
05/18/2017  E1.75 INCH       KNOX               TX   PUBLIC

&&

JP

The office that day

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

Issued	Product	Office	Counties	Lasted
May 18, 11:06 AM CDT	Flood Watch	OUN	Alfalfa, Atoka, Beckham, Blaine, Bryan, Caddo and 41 more	40 hr
May 18, 1:13 PM CDT	Special Weather Statement	OUN	Jackson	32 min
May 18, 1:19 PM CDT	Severe Thunderstorm Warning	OUN	Greer, Harmon, Jackson, Kiowa	56 min
May 18, 1:58 PM CDT	Tornado Warning	OUN	Greer, Harmon, Jackson, Kiowa	47 min
May 18, 2:01 PM CDT	Severe Thunderstorm Warning	OUN	Harmon, Jackson	44 min
May 18, 2:11 PM CDT	Special Weather Statement	OUN	Ellis, Roger Mills	34 min
May 18, 2:13 PM CDT	Special Weather Statement	OUN	Beckham	32 min
May 18, 2:25 PM CDT	Severe Thunderstorm Warning	OUN	Beckham, Custer, Roger Mills, Washita	50 min
May 18, 2:28 PM CDT	Severe Thunderstorm Warning	OUN	Ellis, Roger Mills	47 min
May 18, 2:38 PM CDT	Tornado Warning	OUN	Greer, Jackson, Kiowa, Washita	52 min
May 18, 2:41 PM CDT	Severe Thunderstorm Warning	OUN	Greer, Harmon, Jackson	32 min
May 18, 3:02 PM CDT	Severe Thunderstorm Warning	OUN	Ellis, Harper, Woodward	58 min
May 18, 3:14 PM CDT	Severe Thunderstorm Warning	OUN	Ellis, Woodward	46 min
May 18, 3:17 PM CDT	Severe Thunderstorm Warning	OUN	Caddo, Custer, Kiowa, Washita	58 min
May 18, 3:21 PM CDT	Areal Flood Advisory	OUN	Greer, Kiowa, Washita	3 hr
May 18, 3:29 PM CDT	Tornado Warning	OUN	Caddo, Washita	46 min
May 18, 3:34 PM CDT	Severe Thunderstorm Warning	OUN	Beckham, Greer, Kiowa, Washita	41 min
May 18, 3:37 PM CDT	Severe Thunderstorm Warning	OUN	Major, Woods, Woodward	38 min
May 18, 3:40 PM CDT	Tornado Warning	OUN	Dewey	35 min
May 18, 3:52 PM CDT	Severe Thunderstorm Warning	OUN	Harper, Woods, Woodward	53 min
May 18, 4:02 PM CDT	Tornado Warning	OUN	Woods, Woodward	18 min
May 18, 4:07 PM CDT	Tornado Warning	OUN	Blaine, Caddo, Custer, Washita	38 min
May 18, 4:10 PM CDT	Special Weather Statement	OUN	Alfalfa	35 min
May 18, 4:11 PM CDT	Tornado Warning	OUN	Washita	34 min
May 18, 4:11 PM CDT	Tornado Warning	OUN	Dewey, Major, Woodward	34 min
May 18, 4:11 PM CDT	Tornado Warning	OUN	Tillman	34 min
May 18, 4:18 PM CDT	Severe Thunderstorm Warning	OUN	Alfalfa, Woods	57 min
May 18, 4:26 PM CDT	Severe Thunderstorm Warning	OUN	Ellis, Woodward	49 min
May 18, 4:34 PM CDT	Tornado Warning Tornado observedConsiderable damage threat	OUN	Major, Woods, Woodward	41 min
May 18, 4:35 PM CDT	Tornado Warning	OUN	Woods	40 min
May 18, 4:38 PM CDT	Severe Thunderstorm Warning	OUN	Ellis, Roger Mills	67 min
May 18, 4:40 PM CDT	Tornado Warning	OUN	Caddo, Custer, Washita	25 min
May 18, 4:41 PM CDT	Flash Flood Warning	OUN	Blaine, Caddo, Custer, Washita	3 hr
May 18, 4:42 PM CDT	Tornado Warning	OUN	Blaine, Canadian, Custer	48 min
May 18, 4:43 PM CDT	Severe Thunderstorm Warning	OUN	Tillman	47 min
May 18, 4:53 PM CDT	Special Weather Statement	OUN	Harper	37 min
May 18, 4:53 PM CDT	Tornado Warning	OUN	Tillman	37 min
May 18, 5:03 PM CDT	Tornado Warning Tornado observed	OUN	Woods, Woodward	32 min
May 18, 5:04 PM CDT	Flash Flood Warning	OUN	Tillman	3 hr
May 18, 5:09 PM CDT	Special Weather Statement	OUN	Cleveland, Oklahoma	36 min
May 18, 5:13 PM CDT	Tornado Warning Tornado observed	OUN	Blaine, Canadian, Kingfisher	32 min
May 18, 5:15 PM CDT	Severe Thunderstorm Warning	OUN	Cleveland, Lincoln, McClain, Oklahoma, Pottawatomie	45 min
May 18, 5:22 PM CDT	Special Weather Statement	OUN	Ellis, Harper	38 min
May 18, 5:25 PM CDT	Severe Thunderstorm Warning	OUN	Comanche, Cotton, Tillman	50 min
May 18, 5:29 PM CDT	Severe Thunderstorm Warning	OUN	Blaine, Canadian, Kingfisher	31 min
May 18, 5:34 PM CDT	Severe Thunderstorm Warning	OUN	Alfalfa, Woods	29 min
May 18, 5:39 PM CDT	Severe Thunderstorm Warning	OUN	Woodward	51 min
May 18, 5:40 PM CDT	Special Weather Statement	OUN	Carter	35 min
May 18, 5:42 PM CDT	Severe Thunderstorm Warning	OUN	Dewey, Ellis, Roger Mills	48 min
May 18, 5:48 PM CDT	Severe Thunderstorm Warning	OUN	Comanche, Cotton	27 min
May 18, 5:50 PM CDT	Severe Thunderstorm Warning	OUN	Blaine, Kingfisher	40 min
May 18, 5:57 PM CDT	Severe Thunderstorm Warning	OUN	Cleveland, Lincoln, Logan, Oklahoma, Pottawatomie, Seminole	48 min
May 18, 5:59 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Garvin, Murray	46 min
May 18, 6:07 PM CDT	Special Weather Statement	OUN	Carter	23 min
May 18, 6:12 PM CDT	Severe Thunderstorm Warning	OUN	Comanche, Cotton, Grady, Jefferson, Stephens, Tillman	48 min
May 18, 6:15 PM CDT	Special Weather Statement	OUN	Kay	30 min
May 18, 6:18 PM CDT	Special Weather Statement	OUN	Woods	27 min
May 18, 6:19 PM CDT	Tornado Warning	OUN	Cotton, Stephens	26 min
May 18, 6:27 PM CDT	Severe Thunderstorm Warning	OUN	Garfield, Kingfisher	48 min
May 18, 6:29 PM CDT	Severe Thunderstorm Warning	OUN	Dewey, Major, Woodward	46 min
May 18, 6:30 PM CDT	Special Weather Statement	OUN	Woodward	30 min
May 18, 6:33 PM CDT	Severe Thunderstorm Warning	OUN	Cleveland, Garvin, McClain	42 min
May 18, 6:34 PM CDT	Special Weather Statement	OUN	Ellis	26 min
May 18, 6:44 PM CDT	Severe Thunderstorm Warning	OUN	Woods, Woodward	46 min
May 18, 6:47 PM CDT	Severe Thunderstorm Warning	OUN	Lincoln, Pottawatomie	43 min
May 18, 6:55 PM CDT	Special Weather Statement	OUN	Kingfisher	35 min
May 18, 6:55 PM CDT	Severe Thunderstorm Warning	OUN	Comanche, Cotton, Grady, Jefferson, Stephens, Tillman	50 min
May 18, 1:25 PM CDT	Special Weather Statement	OUN	Foard	50 min
May 18, 1:46 PM CDT	Special Weather Statement	OUN	Hardeman	29 min
May 18, 2:10 PM CDT	Severe Thunderstorm Warning	OUN	Foard, Hardeman, Knox	50 min
May 18, 2:45 PM CDT	Tornado Warning	OUN	Foard, Hardeman	30 min
May 18, 3:00 PM CDT	Tornado Warning	OUN	Foard, Wilbarger	45 min
May 18, 3:10 PM CDT	Severe Thunderstorm Warning	OUN	Foard, Hardeman, Wilbarger	35 min
May 18, 3:39 PM CDT	Tornado Warning	OUN	Wilbarger	36 min
May 18, 3:43 PM CDT	Severe Thunderstorm Warning	OUN	Foard, Hardeman, Wilbarger	47 min
May 18, 4:17 PM CDT	Areal Flood Advisory	OUN	Foard, Hardeman, Wilbarger	3 hr
May 18, 4:20 PM CDT	Severe Thunderstorm Warning	OUN	Wilbarger	40 min
May 18, 5:34 PM CDT	Special Weather Statement	OUN	Baylor	26 min
May 18, 5:56 PM CDT	Severe Thunderstorm Warning	OUN	Baylor, Wilbarger	34 min
May 18, 6:27 PM CDT	Severe Thunderstorm Warning	OUN	Archer, Baylor	33 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.