Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 395, NWS Norman, OK

May 18, 2015Bryan County, Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at May 18, 2015, 4:54 PM CDT for Bryan County, Oklahoma. It was in force for 36 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, 2015, 4:54 PM CDT (21:54 UTC)
Expired: May 18, 2015, 5:30 PM CDT
In force: 36 min
Issued by: NWS Norman, OK
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

County Bryan County, OK

The radar

The Norman radar (KTLX), 179 km from the middle of the area, began a volume at 21:54 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

Shreveport, LA (KBAD), launched 12:00Z, 9.9 hours before the alert went out and 286 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: 840 J/kg
Mixed-layer CIN: -50 J/kg
Mixed-layer LCL: 899 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 86 m²/s²
0-3 km storm-relative helicity: 105 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 1.6

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, 3:45 PM CDT, 1 hour 9 minutes earlier.

Area forecast discussion, May 18, 3:45 PM CDT, 1 hour 9 minutes before

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Hazardous weather outlook, May 18, 12:12 PM CDT, 4 hours 42 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NORMAN OK
1212 PM CDT MON MAY 18 2015

OKZ004>048-050>052-TXZ083>090-191000-
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-
1212 PM CDT MON MAY 18 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...

.RIVER FLOODING...
SOME RIVERS AND STREAMS WILL REMAIN IN FLOOD...ESPECIALLY ACROSS
SOUTHERN OKLAHOMA AND NORTHERN TEXAS. DO NOT DRIVE INTO AREAS
WHERE WATER COVERS THE ROAD.

.THUNDERSTORMS...
A FEW THUNDERSTORMS MAY DEVELOP THIS AFTERNOON IN SOUTHERN
OKLAHOMA AS A COLD FRONT APPROACHES. A BETTER CHANCE FOR
THUNDERSTORMS WILL BE LATER THIS EVENING AND OVERNIGHT ACROSS
SOUTHWEST OKLAHOMA AND WESTERN NORTH TEXAS. STRONG TO SEVERE
THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER WEST TEXAS LATE THIS
AFTERNOON AND EVENING. THESE STORMS SHOULD REACH SOUTHWEST
OKLAHOMA AND WESTERN NORTH TEXAS OVERNIGHT. A FEW OF THESE STORMS
MAY PRODUCE HAIL UP TO THE SIZE OF QUARTERS AND WIND GUSTS OVER 50
MPH.

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

.THUNDERSTORMS...
ON TUESDAY...EARLY MORNING THUNDERSTORMS ARE EXPECTED ACROSS WEST
TEXAS AND FAR WESTERN OKLAHOMA. CLOUDS ASSOCIATED WITH THE STORMS
SHOULD LIMIT THE AMOUNT OF INSTABILITY FARTHER EAST. HOWEVER...IF
STORMS DECREASE IN COVERAGE DURING THE MORNING AND EARLY
AFTERNOON...SOME STRONG TO SEVERE STORMS MAY DEVELOP DURING THE
AFTERNOON...ESPECIALLY IN SOUTHWEST OKLAHOMA AND WESTERN NORTH
TEXAS.

ANOTHER COLD FRONT WILL PUSH ACROSS OKLAHOMA AND NORTH TEXAS ON
WEDNESDAY. A FEW STRONG STORMS WILL BE POSSIBLE AHEAD OF THE FRONT
IN SOUTHERN OKLAHOMA AND NORTH TEXAS.

THUNDERSTORMS WILL BECOME MORE LIKELY BY LATE FRIDAY INTO
SUNDAY. SEVERE STORMS ARE POSSIBLE EACH DAY.

.FLOODING...
SOME RIVERS WILL REMAIN IN OR NEAR FLOOD INTO NEXT WEEKEND. DO
NOT DRIVE INTO AREAS WHERE WATER COVERS THE ROAD. ADDITIONAL RAINS
THROUGH THE WEEK WILL EXACERBATE THE FLOODING PROBLEMS.

GET GRAPHICS AND MORE DETAILS AT WEATHER.GOV/NORMAN...AND FOLLOW
OUR WEATHER FORECAST OFFICE ON TWITTER AND FACEBOOK.

In the hours before

Special weather statement, May 18, 2:34 PM CDT, 2 hours 20 minutes before

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Special weather statement, May 18, 3:00 PM CDT, 1 hour 54 minutes before

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Special weather statement, May 18, 3:30 PM CDT, 1 hour 24 minutes before

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Special weather statement, May 18, 3:33 PM CDT, 1 hour 21 minutes before

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Special weather statement, May 18, 4:13 PM CDT, 41 minutes before

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Special weather statement, May 18, 4:43 PM CDT, 11 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 18, 4:40 AM CDT	Dense Fog Advisory	OUN	Atoka, Blaine, Bryan, Caddo, Canadian, Carter and 24 more	5 hr
May 18, 12:46 PM CDT	Special Weather Statement	OUN	Murray	29 min
May 18, 1:19 PM CDT	Special Weather Statement	OUN	Johnston	26 min
May 18, 1:26 PM CDT	Special Weather Statement	OUN	Carter	34 min
May 18, 1:29 PM CDT	Special Weather Statement	OUN	Hughes	31 min
May 18, 1:57 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Johnston, Marshall	48 min
May 18, 2:05 PM CDT	Special Weather Statement	OUN	Pontotoc	25 min
May 18, 2:34 PM CDT	Special Weather Statement	OUN	Pontotoc	26 min
May 18, 3:00 PM CDT	Special Weather Statement	OUN	Pontotoc	30 min
May 18, 3:30 PM CDT	Special Weather Statement	OUN	Johnston, Pontotoc	30 min
May 18, 3:33 PM CDT	Special Weather Statement	OUN	Kiowa	27 min
May 18, 3:57 PM CDT	Flood Watch	OUN	Alfalfa, Atoka, Beckham, Blaine, Bryan, Caddo and 41 more	39 hr
May 18, 4:13 PM CDT	Special Weather Statement	OUN	Kiowa	32 min
May 18, 4:43 PM CDT	Special Weather Statement	OUN	Bryan	32 min
May 18, 5:27 PM CDT	Special Weather Statement	OUN	Greer	33 min
May 18, 5:46 PM CDT	Special Weather Statement	OUN	Tillman	29 min
May 18, 6:02 PM CDT	Special Weather Statement	OUN	Kiowa	28 min
May 18, 6:15 PM CDT	Special Weather Statement	OUN	Kiowa	30 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.