Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 567, NWS Norman, OK

July 20, 2015Roger Mills County, Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at Jul 20, 2015, 6:39 PM CDT for Roger Mills County, Oklahoma. It was in force for 51 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, 6:39 PM CDT (23:39 UTC)
Expired: Jul 20, 2015, 7:30 PM CDT
In force: 51 min
Issued by: NWS Norman, OK
Area: Storm-based polygon
Hail: 0.88 in
Wind: 70.0 mph

County Roger Mills County, OK

The radar

The Altus AFB radar (KFDR), 161 km from the middle of the area, began a volume at 23:43 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 12:00Z, 11.7 hours before the alert went out and 189 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: 761 J/kg
Mixed-layer CIN: -196 J/kg
Mixed-layer LCL: 1533 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 78 m²/s²
0-3 km storm-relative helicity: 60 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, 4 minutes earlier.

Area forecast discussion, Jul 20, 6:35 PM CDT, 4 minutes before

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Hazardous weather outlook, Jul 20, 11:53 AM CDT, 6 hours 46 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, 5:31 PM CDT, 1 hour 8 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
531 PM CDT MON JUL 20 2015

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

0525 PM     TSTM WND DMG     WEATHERFORD             35.53N 98.71W
07/20/2015                   CUSTER             OK   PUBLIC

            POWER LINES DOWNED BY STRONG WINDS.

&&

MBS

Special weather statement, Jul 20, 5:42 PM CDT, 57 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE NORMAN OK
542 PM CDT MON JUL 20 2015

OKZ021-202330-
BECKHAM OK-
542 PM CDT MON JUL 20 2015

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN BECKHAM COUNTY UNTIL
630 PM CDT...

AT 540 PM CDT...A STRONG THUNDERSTORM WAS LOCATED NEAR ERICK. THIS
STORM WAS NEARLY STATIONARY.

HAZARDS INCLUDE...
WIND GUSTS TO 50 MPH...
VERY HEAVY RAINFALL RESULTING IN LOCALIZED FLOODING...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MONITOR THE WEATHER SITUATION CLOSELY AND BE ALERT FOR THREATENING
WEATHER CONDITIONS.

&&

LAT...LON 3535 10000 3534 9982 3512 9963 3512 9978
      3511 9978 3510 10000
TIME...MOT...LOC 2240Z 301DEG 1KT 3518 9982

Special weather statement, Jul 20, 6:15 PM CDT, 24 minutes before

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Local storm report, Jul 20, 6:29 PM CDT, 10 minutes before

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Special weather statement, Jul 20, 6:30 PM CDT, 9 minutes before

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Special weather statement, Jul 20, 6:36 PM CDT, 3 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, 3:33 PM CDT	Special Weather Statement	OUN	Canadian	42 min
Jul 20, 3:42 PM CDT	Special Weather Statement	OUN	Beckham	48 min
Jul 20, 3:54 PM CDT	Severe Thunderstorm Warning	OUN	Canadian, Kingfisher	36 min
Jul 20, 3:59 PM CDT	Special Weather Statement	OUN	Beckham	31 min
Jul 20, 4:09 PM CDT	Severe Thunderstorm Warning	OUN	Beckham, Roger Mills	51 min
Jul 20, 4:29 PM CDT	Special Weather Statement	OUN	Canadian	46 min
Jul 20, 4:36 PM CDT	Special Weather Statement	OUN	Beckham	39 min
Jul 20, 4:46 PM CDT	Areal Flood Advisory	OUN	Beckham, Roger Mills	3 hr
Jul 20, 4:55 PM CDT	Severe Thunderstorm Warning	OUN	Beckham, Roger Mills	50 min
Jul 20, 4:57 PM CDT	Special Weather Statement	OUN	Custer	63 min
Jul 20, 5:03 PM CDT	Flash Flood Warning	OUN	Beckham, Roger Mills	3 hr
Jul 20, 5:23 PM CDT	Severe Thunderstorm Warning	OUN	Custer	52 min
Jul 20, 5:33 PM CDT	Areal Flood Advisory	OUN	Custer	3 hr
Jul 20, 5:42 PM CDT	Special Weather Statement	OUN	Beckham	48 min
Jul 20, 5:54 PM CDT	Flash Flood Warning	OUN	Custer	3 hr
Jul 20, 6:15 PM CDT	Special Weather Statement	OUN	Harmon	30 min
Jul 20, 6:30 PM CDT	Special Weather Statement	OUN	Roger Mills	60 min
Jul 20, 6:36 PM CDT	Special Weather Statement	OUN	Caddo	39 min
Jul 20, 6:52 PM CDT	Areal Flood Advisory	OUN	Ellis, Roger Mills	3 hr
Jul 20, 6:54 PM CDT	Special Weather Statement	OUN	Kiowa	66 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.