Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2013

Severe Thunderstorm Warning 360, NWS Norman, OK

May 21, 2013Cleveland County, McClain County, Pottawatomie County, Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at May 21, 2013, 3:42 AM CDT for Cleveland County, McClain County, Pottawatomie County, Oklahoma. It was in force for 48 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 21, 2013, 3:42 AM CDT (08:42 UTC)
Expired: May 21, 2013, 4:30 AM CDT
In force: 48 min
Issued by: NWS Norman, OK
Area: Storm-based polygon

Counties Cleveland County, OK, McClain County, OK, Pottawatomie County, OK

The radar

The Norman radar (KTLX), 22 km from the middle of the area, began a volume at 08:44 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 21, 12:03 AM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Norman, OK (KOUN), launched 00:00Z, 8.7 hours before the alert went out and 17 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: 1675 J/kg
Mixed-layer CIN: -83 J/kg
Mixed-layer LCL: 1192 m above ground
0-6 km bulk shear: 62 kt
0-1 km storm-relative helicity: 270 m²/s²
0-3 km storm-relative helicity: 238 m²/s²
Significant tornado parameter: 1.2
Supercell composite: 8.8

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 21, 3:22 AM CDT, 20 minutes earlier.

Area forecast discussion, May 21, 3:22 AM CDT, 20 minutes before

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Hazardous weather outlook, May 20, 9:41 PM CDT, 6 hours 1 minute before

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE NORMAN OK
941 PM CDT MON MAY 20 2013

OKZ004>048-050>052-TXZ083>090-211000-
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-
945 PM CDT MON MAY 20 2013

THIS HAZARDOUS WEATHER OUTLOOK COVERS NORTHERN...WESTERN...
CENTRAL...AND SOUTHERN OKLAHOMA...AND WESTERN NORTH TEXAS.

.DAY ONE...TONIGHT...

THUNDERSTORM OUTLOOK...
A MODERATE RISK OF SEVERE STORMS CONTINUES FOR SOUTHERN OKLAHOMA INTO
NORTH TEXAS...WITH A SLIGHT RISK OF SEVERE STORMS FROM NORTHERN
OKLAHOMA THROUGH WESTERN NORTH TEXAS.

LOCATION...
THE MODERATE RISK EXTENDS SOUTH OF A LINE FROM CALVIN TO SULPHUR TO
HENRIETTA TEXAS. THE SLIGHT RISK EXTENDS SOUTH OF A LINE FROM
MORRISON TO SEWARD TO YUKON TO LAWTON TO SEYMOUR TEXAS...COVERING
LOCATIONS SOUTH AND EAST TO THE MODERATE RISK.

TIMING...
SEVERE STORMS REMAIN ON GOING ACROSS FAR SOUTHERN OKLAHOMA AND NORTHERN
TEXAS. ELEVATED ISOLATED STORMS ALSO CONTINUE TO DEVELOP ACROSS CENTRAL
OKLAHOMA. THIS NEW DEVELOPMENT OF STORMS BEHIND THE PRIMARY FRONT IS
EXPECTED TO CONTINUE THROUGH THE EARLY MORNING HOURS.

IMPACTS...
THE TORNADO THREAT REMAINS...HOWEVER...LARGE DESTRUCTIVE HAIL AND DAMAGING
WINDS REMAIN THE PRIMARY CONCERNS. ONGOING STORMS HAVE BEEN CAPABLE OF
80 MPH WINDS AND BASEBALL SIZED HAIL.

RECOMMENDED ACTIONS...
STORM SPOTTER GROUPS AND EMERGENCY MANAGEMENT PERSONNEL ACROSS THE
RISK AREAS SHOULD PLAN TO CONTINUE SEVERE WEATHER OPERATIONS THROUGH
THE EARLY MORNING HOURS.

DISCUSSION...
OVERALL...THE FRONTAL BOUNDARY HAS STALLED FROM NORTHEASTERN THROUGH
CENTRAL OKLAHOMA...INTO WESTERN NORTH TEXAS. ONGOING STORMS REMAIN
ROOTED TO THIS BOUNDARY...AS IT CONTINUES TO PROVIDE LIFT FOR THE
CONTINUED DEVELOPMENT OF STORMS. INSTABILITY REMAINS SUFFICIENT ALONG
AND AHEAD OF THE BOUNDARY...WITH WIND FIELDS CONTINUING TO SUPPORT
ROTATING UPDRAFTS.

EXPECT GENERAL THUNDERSTORMS TO REDEVELOP LATER TONIGHT THROUGH
TUESDAY MORNING AS THE FRONT SLOWLY RETREATS NORTHWESTWARD OVERNIGHT.
WIDESPREAD SEVERE WEATHER IS NOT ANTICIPATED AT THIS TIME...HOWEVER
A FEW STRONG TO SEVERE STORMS CANNOT BE RULED OUT.

PROBABILITY TABLE...
VALID THROUGH 700 AM CDT TUESDAY MAY 21.
PROBABILITY OF THUNDERSTORMS OCCURRING IN THE
              NWS NORMAN COUNTY WARNING AREA...100 PERCENT.
PROBABILITY OF SEVERE STORMS IF STORMS OCCUR...100 PERCENT.

OTHER HAZARDOUS WEATHER...
CONTINUED TRAINING OF STORMS WILL RESULT IN INCREASED FLOODING OF CREEKS...
SMALL STREAMS...AND ROAD WAYS. THIS WILL BE ESPECIALLY TRUE ACROSS THE
RED RIVER VALLEY REGION.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY...

THUNDERSTORM OUTLOOK...
SEVERE STORMS WILL BE POSSIBLE AGAIN ON TUESDAY...MAINLY ACROSS THE
SOUTHEAST HALF OF OKLAHOMA. ISOLATED SEVERE STORMS WILL BE POSSIBLE
EACH DAY FROM WEDNESDAY THROUGH FRIDAY. THUNDERSTORMS ARE NOT
CURRENTLY EXPECTED ON SATURDAY AND SUNDAY.

OTHER HAZARDOUS WEATHER...
NONE.

THE NEXT SCHEDULED HAZARDOUS WEATHER OUTLOOK WILL BE ISSUED AT 5 AM
TUESDAY AND UPDATED AS NEEDED.

KURTZ

In the hours before

Special weather statement, May 21, 2:26 AM CDT, 1 hour 16 minutes before

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Special weather statement, May 21, 2:38 AM CDT, 1 hour 4 minutes before

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Special weather statement, May 21, 3:02 AM CDT, 40 minutes before

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Special weather statement, May 21, 3:08 AM CDT, 34 minutes before

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Special weather statement, May 21, 3:12 AM CDT, 30 minutes before

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Special weather statement, May 21, 3:28 AM CDT, 14 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 20, 7:01 PM CDT	Tornado Warning	OUN	Carter, Love, Marshall	44 min
May 20, 7:19 PM CDT	Tornado Warning	OUN	Johnston, Marshall	26 min
May 20, 7:35 PM CDT	River Flood Warning	OUN	Oklahoma	3 hr
May 20, 7:37 PM CDT	Severe Thunderstorm Warning	OUN	Atoka, Coal, Johnston	68 min
May 20, 7:40 PM CDT	Severe Thunderstorm Warning	OUN	Bryan, Johnston, Marshall	50 min
May 20, 7:44 PM CDT	Tornado Warning	OUN	Atoka, Coal, Johnston	46 min
May 20, 7:55 PM CDT	Severe Thunderstorm Warning	OUN	Love	50 min
May 20, 8:11 PM CDT	Severe Thunderstorm Warning	OUN	Atoka, Bryan	49 min
May 20, 8:28 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Johnston, Love, Marshall	47 min
May 20, 9:06 PM CDT	Severe Thunderstorm Warning	OUN	Atoka, Bryan, Johnston	39 min
May 20, 9:09 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Johnston, Marshall, Murray	51 min
May 20, 9:17 PM CDT	Special Weather Statement	OUN	Oklahoma	28 min
May 20, 9:30 PM CDT	Areal Flood Advisory	OUN	Carter, Johnston	3 hr
May 20, 9:44 PM CDT	Severe Thunderstorm Warning	OUN	Atoka, Bryan	46 min
May 20, 10:00 PM CDT	Severe Thunderstorm Warning	OUN	Comanche, Cotton	45 min
May 20, 10:04 PM CDT	Tornado Warning	OUN	Atoka, Bryan	26 min
May 20, 10:25 PM CDT	Tornado Warning	OUN	Atoka	35 min
May 20, 10:33 PM CDT	Special Weather Statement	OUN	Coal	27 min
May 20, 10:38 PM CDT	Severe Thunderstorm Warning	OUN	Garvin, Murray, Pontotoc	52 min
May 20, 10:46 PM CDT	Severe Thunderstorm Warning	OUN	Comanche, Cotton, Stephens	44 min
May 20, 11:20 PM CDT	Severe Thunderstorm Warning	OUN	Atoka, Coal	25 min
May 20, 11:25 PM CDT	Severe Thunderstorm Warning	OUN	Garvin, Murray, Pontotoc	50 min
May 20, 11:28 PM CDT	Severe Thunderstorm Warning	OUN	Stephens	47 min
May 20, 11:50 PM CDT	Special Weather Statement	OUN	McClain	25 min
May 20, 11:58 PM CDT	Severe Thunderstorm Warning	OUN	Coal, Hughes	47 min
May 21, 12:12 AM CDT	Severe Thunderstorm Warning	OUN	Garvin, Murray	48 min
May 21, 12:13 AM CDT	Severe Thunderstorm Warning	OUN	Pontotoc, Seminole	47 min
May 21, 12:41 AM CDT	Severe Thunderstorm Warning	OUN	Garvin, McClain, Murray, Pontotoc	49 min
May 21, 12:49 AM CDT	Severe Thunderstorm Warning	OUN	Hughes, Pontotoc	41 min
May 21, 1:10 AM CDT	Severe Thunderstorm Warning	OUN	Hughes, Pontotoc, Seminole	50 min
May 21, 1:33 AM CDT	Special Weather Statement	OUN	Hughes	27 min
May 21, 1:41 AM CDT	Severe Thunderstorm Warning	OUN	Coal, Hughes, Pontotoc	49 min
May 21, 2:16 AM CDT	Special Weather Statement	OUN	Pottawatomie	29 min
May 21, 2:26 AM CDT	Special Weather Statement	OUN	Coal	34 min
May 21, 2:38 AM CDT	Special Weather Statement	OUN	Pottawatomie	37 min
May 21, 3:08 AM CDT	Special Weather Statement	OUN	Hughes	37 min
May 21, 3:12 AM CDT	Special Weather Statement	OUN	Seminole	33 min
May 21, 3:28 AM CDT	Special Weather Statement	OUN	McClain	32 min
May 21, 3:56 AM CDT	Special Weather Statement	OUN	Hughes	34 min
May 21, 3:58 AM CDT	Special Weather Statement	OUN	Kiowa	32 min
May 21, 4:29 AM CDT	Special Weather Statement	OUN	Pottawatomie	31 min
May 21, 5:00 AM CDT	Severe Thunderstorm Warning	OUN	Caddo, Comanche	45 min
May 21, 5:25 AM CDT	Severe Thunderstorm Warning	OUN	Caddo, Comanche, Grady	50 min
May 21, 6:00 AM CDT	Severe Thunderstorm Warning	OUN	Cleveland, Garvin, Grady, McClain	30 min
May 21, 6:29 AM CDT	Special Weather Statement	OUN	Cleveland	31 min
May 21, 7:14 AM CDT	Special Weather Statement	OUN	Tillman	46 min
May 21, 7:16 AM CDT	Special Weather Statement	OUN	Stephens	44 min
May 21, 7:39 AM CDT	Areal Flood Advisory	OUN	Coal, Garvin, Hughes, Johnston, Murray, Pontotoc and 1 more	3 hr
May 21, 7:56 AM CDT	Special Weather Statement	OUN	Cotton, Jefferson, Stephens, Tillman	49 min
May 21, 8:18 AM CDT	Special Weather Statement	OUN	McClain	27 min
May 21, 8:24 AM CDT	Special Weather Statement	OUN	Cleveland, Oklahoma	36 min
May 21, 8:34 AM CDT	Special Weather Statement	OUN	Atoka	26 min
May 21, 8:40 AM CDT	Special Weather Statement	OUN	Carter, Murray	35 min
May 21, 8:56 AM CDT	Special Weather Statement	OUN	Cleveland	34 min
May 21, 8:58 AM CDT	Special Weather Statement	OUN	Greer, Harmon	47 min
May 21, 9:06 AM CDT	Areal Flood Advisory	OUN	Atoka, Coal	3 hr
May 21, 9:16 AM CDT	Severe Thunderstorm Warning	OUN	Beckham, Greer, Harmon, Jackson	44 min
May 21, 9:24 AM CDT	Special Weather Statement	OUN	Cleveland, McClain	36 min
May 21, 9:50 AM CDT	Special Weather Statement	OUN	Jackson	40 min
May 21, 9:54 AM CDT	Severe Thunderstorm Warning	OUN	Beckham, Greer, Harmon, Jackson, Kiowa, Washita	51 min
May 21, 10:17 AM CDT	Severe Thunderstorm Warning	OUN	Kiowa, Washita	43 min
May 21, 10:18 AM CDT	Severe Thunderstorm Warning	OUN	Kiowa, Washita	42 min
May 21, 10:24 AM CDT	Special Weather Statement	OUN	Jackson, Tillman	51 min
May 21, 10:49 AM CDT	Special Weather Statement	OUN	Cleveland	26 min
May 21, 10:58 AM CDT	Severe Thunderstorm Warning	OUN	Caddo, Canadian, Kiowa, Washita	47 min
May 21, 11:10 AM CDT	Special Weather Statement	OUN	Cotton, Jefferson	50 min
May 21, 11:28 AM CDT	Severe Thunderstorm Warning	OUN	Cotton, Jefferson, Stephens	62 min
May 21, 11:30 AM CDT	Severe Thunderstorm Warning	OUN	Caddo, Canadian, Grady, Kingfisher	45 min
May 21, 11:53 AM CDT	Special Weather Statement	OUN	Cleveland, Oklahoma	22 min
May 21, 11:59 AM CDT	Severe Thunderstorm Warning	OUN	Canadian, Kingfisher, Logan, Oklahoma	46 min
May 21, 12:10 PM CDT	Special Weather Statement	OUN	Pottawatomie, Seminole	35 min
May 21, 12:15 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Garvin, Jefferson, Murray, Stephens	45 min
May 21, 12:23 PM CDT	Special Weather Statement	OUN	Cleveland, McClain, Pottawatomie	52 min
May 21, 12:25 PM CDT	Special Weather Statement	OUN	Lincoln, Oklahoma	50 min
May 21, 12:45 PM CDT	Special Weather Statement	OUN	Lincoln, Payne	45 min
May 21, 12:49 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Garvin, Johnston, Marshall, Murray, Pontotoc	56 min
May 21, 12:52 PM CDT	Special Weather Statement	OUN	Garvin, Hughes, Pottawatomie, Seminole	53 min
May 21, 12:53 PM CDT	Areal Flood Advisory	OUN	Carter, Johnston, Love, Marshall, Murray, Pontotoc	3 hr
May 21, 1:20 PM CDT	Special Weather Statement	OUN	Coal, Hughes	55 min
May 21, 1:27 PM CDT	Areal Flood Advisory	OUN	Atoka, Bryan, Coal, Hughes, Johnston, Marshall and 1 more	3 hr

Nearby

Severe Thunderstorm Warnings in Oklahoma, 2013 Every severe thunderstorm warning in 2013

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.