Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 653, NWS Norman, OK

August 17, 2009Blaine County, Dewey County, Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at Aug 17, 2009, 6:22 PM CDT for Blaine County, Dewey County, Oklahoma. It was in force for 68 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
Aug 17, 2009, 6:22 PM CDT (23:22 UTC)
Expired
Aug 17, 2009, 7:30 PM CDT
In force
68 min
Issued by
NWS Norman, OK
Area
Storm-based polygon

Counties Blaine County, OK, Dewey County, OK

The radar

The Vance AFB radar (KVNX), 104 km from the middle of the area, began a volume at 23:22 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Aug 17, 3:18 PM CDTSevere Thunderstorm WatchSPC10 hr

The nearest sounding before it

Lamont, OK (KLMN), launched 12:00Z, 11.4 hours before the alert went out and 135 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-pSkew-T log-p diagram, Lamont, OK at 12:00Z on 2009-08-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1355 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lamont, OK at 12:00Z on 2009-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 188 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
1355 J/kg
Mixed-layer CIN
-180 J/kg
Mixed-layer LCL
1077 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
188 m²/s²
0-3 km storm-relative helicity
311 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.8

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 Aug 17, 2:59 PM CDT, 3 hours 23 minutes earlier.

Area forecast discussion, Aug 17, 2:59 PM CDT, 3 hours 23 minutes before
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Hazardous weather outlook, Aug 17, 12:00 PM CDT, 6 hours 22 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NORMAN OK
1200 PM CDT MON AUG 17 2009

OKZ004>048-050>052-TXZ083>090-181000-
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-
1200 PM CDT MON AUG 17 2009

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

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

THUNDERSTORM OUTLOOK...
THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THROUGH TONIGHT
ACROSS PORTIONS OF OKLAHOMA.

LOCATION...
THE SLIGHT RISK AREA IS NORTH OF INTERSTATE 40.

TIMING...
THE MOST LIKELY TIME FOR SEVERE THUNDERSTORMS WILL BE FROM LATE
AFTERNOON THROUGH EARLY TUESDAY MORNING.

RECOMMENDED ACTIONS...
STORM SPOTTER GROUPS AND EMERGENCY MANAGEMENT PERSONNEL ACROSS THE
RISK AREA SHOULD PLAN FOR SEVERE WEATHER OPERATIONS FROM THIS
AFTERNOON UNTIL EARLY TUESDAY MORNING.

DISCUSSION...
MODERATE INSTABILITY... COMBINED WITH SURFACE BOUNDARIES... AN UPPER
LEVEL TROUGH... AND MODERATE VERTICAL WIND SHEAR... WILL BRING A
CHANCE OF SEVERE THUNDERSTORMS TO NORTHERN OKLAHOMA LATER TODAY. INSOLATION
AND AN OUTFLOW BOUNDARY ACROSS CENTRAL OKLAHOMA WILL PROVIDE
SUFFICIENT LIFT FOR THUNDERSTORMS LATER THIS AFTERNOON.
THUNDERSTORMS WILL BE CAPABLE OF PRODUCING VERY HEAVY RAIN AND
LOCALIZED FLOODING. A FEW THUNDERSTORMS MAY ALSO MAKE LARGE HAIL AND
DAMAGING WINDS.

PROBABILITY TABLE...
VALID THROUGH 700 AM CDT TUESDAY AUG 18.
PROBABILITY OF THUNDERSTORMS OCCURRING IN THE
              NWS NORMAN COUNTY WARNING AREA...100 PERCENT.
PROBABILITY OF SEVERE STORMS IF STORMS OCCUR...70 PERCENT.

OTHER HAZARDOUS WEATHER...
A FLOOD WATCH IS EFFECTIVE FOR THE NORTHERN HALF OF OKLAHOMA FROM
LATE THIS AFTERNOON THROUGH MID-DAY TUESDAY.

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

THUNDERSTORM OUTLOOK...
SEVERE THUNDERSTORMS ARE POSSIBLE TUESDAY AND TUESDAY NIGHT.
THUNDERSTORM CHANCES RECEDE BEYOND WEDNESDAY MORNING.

OTHER HAZARDOUS WEATHER...
A FLOOD WATCH IS EFFECTIVE FOR THE NORTHERN HALF OF OKLAHOMA UNTIL
MID-DAY TUESDAY. THUNDERSTORMS TUESDAY MORNING WILL LIKELY GENERATE
VERY HEAVY RAINFALL.

THE NEXT SCHEDULED HAZARDOUS WEATHER OUTLOOK WILL BE ISSUED AT 7 AM
TUESDAY.

In the hours before

Special weather statement, Aug 17, 5:47 PM CDT, 35 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE NORMAN OK
547 PM CDT MON AUG 17 2009

OKZ015-017-172330-
DEWEY OK-BLAINE OK-
547 PM CDT MON AUG 17 2009

...SIGNIFICANT WEATHER ADVISORY...

THIS SIGNIFICANT WEATHER ADVISORY IS FOR BLAINE AND DEWEY COUNTIES.

A STRONG THUNDERSTORM WAS LOCATED 5 MILES SOUTHWEST OF EAGLE CITY AT
546 PM CDT...MOVING EAST AT 15 MPH. SMALL HAIL AND WINDS AROUND 50
MPH ARE LIKELY. ADDITIONAL THUNDERSTORMS WERE FORMING ON AN OUTFLOW
BOUNDARY EXTENDING WEST TOWARD TALOGA. SEVERE WEATHER IS POSSIBLE AS
STORM STRENGTHEN THIS EVENING.

LAT...LON 3577 9821 3585 9890 3599 9905 3616 9862
      3616 9822

BURKE

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 16, 7:14 PM CDTSevere Thunderstorm WarningOUNGarfield61 min
Aug 16, 7:19 PM CDTSevere Thunderstorm WarningOUNAlfalfa, Garfield, Grant41 min
Aug 16, 7:54 PM CDTSevere Thunderstorm WarningOUNGarfield, Grant66 min
Aug 16, 8:14 PM CDTSevere Thunderstorm WarningOUNHarmon46 min
Aug 16, 8:38 PM CDTSevere Thunderstorm WarningOUNKay37 min
Aug 16, 8:57 PM CDTSevere Thunderstorm WarningOUNGarfield63 min
Aug 16, 9:17 PM CDTFlash Flood WarningOUNGarfield3 hr
Aug 16, 9:25 PM CDTSevere Thunderstorm WarningOUNMajor35 min
Aug 16, 9:59 PM CDTSevere Thunderstorm WarningOUNAlfalfa, Garfield, Major61 min
Aug 16, 10:59 PM CDTAreal Flood AdvisoryOUNMajor3 hr
Aug 16, 11:00 PM CDTSevere Thunderstorm WarningOUNGarfield60 min
Aug 16, 11:59 PM CDTSevere Thunderstorm WarningOUNGarfield31 min
Aug 17, 12:07 AM CDTFlash Flood WarningOUNGarfield5 hr
Aug 17, 5:37 AM CDTAreal Flood WarningOUNGarfield6 hr
Aug 17, 11:54 AM CDTFlash Flood WatchOUNAlfalfa, Beckham, Blaine, Caddo, Canadian, Custer and 17 more70 hr

Nearby

Severe Thunderstorm Warnings in Oklahoma, 2009Every severe thunderstorm warning in 2009

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.