Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 569, NWS Norman, OK

July 20, 2015Ellis County, Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at Jul 20, 2015, 7:22 PM CDT for Ellis County, Oklahoma. It was in force for 38 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: Jul 20, 2015, 7:22 PM CDT (00:22 UTC)
Expired: Jul 20, 2015, 8:00 PM CDT
In force: 38 min
Issued by: NWS Norman, OK
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

County Ellis County, OK

The radar

The Vance AFB radar (KVNX), 157 km from the middle of the area, began a volume at 00:22 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 nearest sounding before it

Amarillo Airport, TX (KAMA), launched 00:00Z, 0.4 hours before the alert went out and 207 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: 1981 J/kg
Mixed-layer CIN: -16 J/kg
Mixed-layer LCL: 1533 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: 29 m²/s²
0-3 km storm-relative helicity: 108 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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 Jul 20, 6:35 PM CDT, 47 minutes earlier.

Area forecast discussion, Jul 20, 6:35 PM CDT, 47 minutes before

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Hazardous weather outlook, Jul 20, 11:53 AM CDT, 7 hours 29 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NORMAN OK
1153 AM CDT MON JUL 20 2015

OKZ004>048-050>052-TXZ083>090-211700-
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-
1153 AM CDT MON JUL 20 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHERN...
WESTERN...CENTRAL...AND SOUTHERN OKLAHOMA...AND WESTERN NORTH
TEXAS.

.DAY ONE...THIS AFTERNOON AND TONIGHT...

.HEAT...
TODAY WILL BE ANOTHER HOT AND HUMID DAY WITH HEAT INDEX VALUES
REACHING 100 TO 108 ACROSS MUCH OF OKLAHOMA AND NORTH TEXAS.

.THUNDERSTORMS...
SHOWERS AND THUNDERSTORMS ARE POSSIBLE ACROSS MAINLY NORTHERN AND
CENTRAL OKLAHOMA THIS AFTERNOON AND TONIGHT. THUNDERSTORMS WILL
DEVELOP THIS AFTERNOON IN PARTS OF NORTHERN OKLAHOMA AND THEN BECOME
MORE WIDESPREAD ACROSS NORTHERN AND CENTRAL OKLAHOMA THIS EVENING
AND OVERNIGHT. SOME OF THESE STORMS MAY BECOME STRONG TO SEVERE
LATE THIS AFTERNOON AND THIS EVENING. THERE IS A MARGINAL RISK OF
SEVERE THUNDERSTORMS MAINLY ALONG AND NORTH OF A LINE FROM HOLLIS
AND HOBART... TO NORMAN AND SHAWNEE. THESE STORMS MAY PRODUCE HAIL
UP TO THE SIZE OF HALF DOLLARS AND WINDS OF 60 TO 70 MPH.

THE POTENTIAL FOR SEVERE STORMS WILL DIMINISH AFTER SUNSET BUT
THUNDERSTORMS WILL REMAIN POSSIBLE INTO TUESDAY MORNING. CLOUD TO
GROUND LIGHTNING AND HEAVY DOWNPOURS WILL BE THE MAIN CONCERNS
OVERNIGHT INTO THE MORNING.

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

.HEAT...
HOT WEATHER WILL CONTINUE THROUGH THE WEEK... WITH THE EXCEPTION
OF A BRIEF PERIOD OF SOMEWHAT COOLER WEATHER IN NORTHERN AND
CENTRAL OKLAHOMA ON TUESDAY AND WEDNESDAY AS A COLD FRONT MOVES
INTO THE AREA. HOWEVER... HOT WEATHER WILL REMAIN SOUTH OF THE
FRONT AND SPREAD BACK ACROSS THE ENTIRE AREA BY THURSDAY.
MAXIMUM AFTERNOON HEAT INDEX VALUES IN THE TRIPLE DIGITS WILL BE
COMMON.

.THUNDERSTORMS...
SCATTERED TO NUMEROUS THUNDERSTORMS ARE EXPECTED AGAIN TUESDAY AND
WEDNESDAY WITH THE HIGHEST CHANCES OF STORMS ACROSS NORTHERN
OKLAHOMA. STRONG TO MARGINALLY SEVERE STORMS WILL BE POSSIBLE
AGAIN ACROSS THE NORTHERN HALF OF OKLAHOMA ON TUESDAY.

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, Jul 20, 6:29 PM CDT, 53 minutes before

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Special weather statement, Jul 20, 6:30 PM CDT, 52 minutes before

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Special weather statement, Jul 20, 6:36 PM CDT, 46 minutes before

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Local storm report, Jul 20, 6:52 PM CDT, 30 minutes before

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Local storm report, Jul 20, 6:54 PM CDT, 28 minutes before

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Special weather statement, Jul 20, 6:54 PM CDT, 28 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
Jul 20, 7:05 PM CDT	Special Weather Statement	OUN	Alfalfa	55 min
Jul 20, 7:09 PM CDT	Special Weather Statement	OUN	Ellis	36 min
Jul 20, 7:18 PM CDT	Severe Thunderstorm Warning	OUN	Alfalfa, Woods	42 min
Jul 20, 7:36 PM CDT	Special Weather Statement	OUN	Grady	39 min
Jul 20, 7:41 PM CDT	Areal Flood Advisory	OUN	Ellis	3 hr
Jul 20, 7:54 PM CDT	Special Weather Statement	OUN	Ellis	66 min
Jul 20, 8:09 PM CDT	Areal Flood Advisory	OUN	Grady	3 hr
Jul 20, 8:18 PM CDT	Areal Flood Advisory	OUN	Ellis	3 hr
Jul 20, 8:20 PM CDT	Special Weather Statement	OUN	Cleveland	40 min
Jul 20, 8:22 PM CDT	Special Weather Statement	OUN	Ellis	53 min
Jul 20, 8:27 PM CDT	Special Weather Statement	OUN	Grady	48 min
Jul 20, 8:34 PM CDT	Special Weather Statement	OUN	Oklahoma	56 min
Jul 20, 8:49 PM CDT	Areal Flood Advisory	OUN	Canadian, Oklahoma	3 hr
Jul 20, 9:10 PM CDT	Special Weather Statement	OUN	Major	50 min
Jul 20, 9:22 PM CDT	Areal Flood Advisory	OUN	Oklahoma	3 hr
Jul 20, 9:30 PM CDT	Areal Flood Advisory	OUN	Major	3 hr
Jul 20, 9:38 PM CDT	Special Weather Statement	OUN	Canadian	52 min
Jul 20, 9:41 PM CDT	Areal Flood Advisory	OUN	Logan	3 hr
Jul 20, 10:27 PM CDT	Areal Flood Advisory	OUN	Kingfisher	3 hr
Jul 20, 11:04 PM CDT	Areal Flood Advisory	OUN	Garfield, Kingfisher	3 hr
Jul 20, 11:58 PM CDT	Special Weather Statement	OUN	Garfield	47 min
Jul 21, 12:17 AM CDT	Areal Flood Advisory	OUN	Kingfisher	3 hr
Jul 21, 1:21 AM CDT	Areal Flood Advisory	OUN	Beckham, Blaine, Custer, Dewey, Ellis, Kingfisher and 4 more	4 hr
Jul 21, 2:04 AM CDT	Areal Flood Advisory	OUN	Kay	3 hr
Jul 21, 2:59 AM CDT	Areal Flood Advisory	OUN	Blaine, Caddo, Canadian, Kingfisher, Lincoln, Logan and 2 more	3 hr
Jul 21, 3:47 AM CDT	Areal Flood Advisory	OUN	Blaine, Caddo, Custer	118 min
Jul 21, 5:21 PM CDT	Special Weather Statement	OUN	Comanche	54 min
Jul 21, 6:44 PM CDT	Special Weather Statement	OUN	Cotton	46 min
Jul 21, 6:48 PM CDT	Special Weather Statement	OUN	Tillman	42 min

Nearby

Severe Thunderstorm Warnings in Oklahoma, 2015 Every severe thunderstorm warning in 2015

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.