Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 583, NWS Norman, OK

July 21, 20094 counties in Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at Jul 21, 2009, 5:04 AM CDT for 4 counties in Oklahoma. It was in force for 41 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 21, 2009, 5:04 AM CDT (10:04 UTC)
Expired
Jul 21, 2009, 5:45 AM CDT
In force
41 min
Issued by
NWS Norman, OK
Area
Storm-based polygon

Counties McClain County, OK, Pontotoc County, OK, Pottawatomie County, OK, Seminole County, OK

The radar

The Norman radar (KTLX), 47 km from the middle of the area, began a volume at 10:03 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
Jul 20, 10:27 PM CDTSevere Thunderstorm WatchSPC8 hr

The nearest sounding before it

Lamont, OK (KLMN), launched 00:00Z, 10.1 hours before the alert went out and 184 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 00:00Z on 2009-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 00:00Z on 2009-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 19 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3054 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
19 m²/s²
0-3 km storm-relative helicity
100 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 21, 2:33 AM CDT, 2 hours 31 minutes earlier.

Area forecast discussion, Jul 21, 2:33 AM CDT, 2 hours 31 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
233 AM CDT TUE JUL 21 2009

.DISCUSSION...
COMPLEX OF STORMS THAT CONT TO AFFECT MUCH OF THE AREA EARLY THIS
MORNING WILL PUSH SOUTH OF THE AREA QUICKLY THIS MORNING LEAVING
MOST OF THE AREA DRY FOR TODAY. MODELS ARE HINTING AT ANOTHER
COMPLEX OF STORMS DEVELOPING THIS TIME ACROSS NEW MEXICO AND THEN
TRANSLATING ESE. THINK GFS IS TOO FAR EAST AND MOST OF THIS COMPLEX
SHOULD REMAIN WEST OF THE AREA HOWEVER WILL PUT SOME LOW POPS ACROSS
SOUTHWEST OK AND WESTERN NORTH TEXAS LATE TONIGHT INTO WED.
ALSO...PROBABLY DUE TO SOME OF THIS PRECIP AND CLOUD COVER THE GFS
THINKS WILL BE OVER THE AREA MAV GUIDANCE TEMPS FOR WED LOOK A
LITTLE COOL. SO WILL RAISE THEM A FEW DEGREES AS MORE SUNSHINE
SHOULD BE MAKING IT THROUGH AT LEAST BY AFTN AND IT IS NOW GETTING
TO BE LATE JULY.

BEYOND THIS TIMEFRAME NORTHWEST FLOW CONT... ALTHOUGH NO MAJOR WAVES
ARE EVIDENT UNTIL LARGER WAVE ROTATES THROUGH GREAT LAKES OVER THE
WEEKEND... WHICH BRINGS A FRONT SOUTH INTO THE SOUTHERN PLAINS.
INITIALLY BETTER FORCING REMAINS TO OUR NORTHEAST LIMITING PRECIP
WITH THE FRONT. HOWEVER POST-FRONTAL CHANCES MAY BE HIGHER. AS GFS
WOULD SUGGEST AND LATEST ECMWF NORTHWEST FLOW CONT INTO NEXT WEEK
WHICH SHOULD KEEP RAIN CHANCES IN THE FORECAST PERIODICALLY AND NO
RETURN TO THE OPPRESSIVE HEAT OF A COUPLE OF WEEKS AGO.

&&

.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK  90  65  90  64 /  20   0   0   0
HOBART OK         95  68  90  65 /  20  10  10  10
WICHITA FALLS TX  97  70  91  68 /  30  20  20  20
GAGE OK           88  61  90  63 /  10  10   0   0
PONCA CITY OK     85  63  89  63 /  20   0   0   0
DURANT OK         92  67  90  68 /  40   0   0  20

&&

.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&

24/30
Hazardous weather outlook, Jul 21, 5:00 AM CDT, 4 minutes before
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In the hours before

Special weather statement, Jul 21, 3:38 AM CDT, 1 hour 26 minutes before
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Special weather statement, Jul 21, 3:41 AM CDT, 1 hour 23 minutes before
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Local storm report, Jul 21, 3:42 AM CDT, 1 hour 22 minutes before
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Special weather statement, Jul 21, 4:18 AM CDT, 46 minutes before
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Special weather statement, Jul 21, 4:40 AM CDT, 24 minutes before
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Special weather statement, Jul 21, 4:53 AM CDT, 11 minutes before
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The office that day

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

IssuedProductOfficeCountiesLasted
Jul 20, 8:44 PM CDTSevere Thunderstorm WarningOUNGrant76 min
Jul 20, 9:48 PM CDTSevere Thunderstorm WarningOUNGarfield, Noble72 min
Jul 20, 10:02 PM CDTSevere Thunderstorm WarningOUNAlfalfa, Grant58 min
Jul 20, 10:11 PM CDTSevere Thunderstorm WarningOUNMajor, Woods, Woodward94 min
Jul 20, 10:26 PM CDTSevere Thunderstorm WarningOUNGarfield, Major79 min
Jul 20, 11:11 PM CDTSevere Thunderstorm WarningOUNAlfalfa, Grant64 min
Jul 20, 11:36 PM CDTSevere Thunderstorm WarningOUNBlaine, Kingfisher69 min
Jul 20, 11:41 PM CDTSevere Thunderstorm WarningOUNBlaine, Custer, Dewey, Major, Woodward79 min
Jul 20, 11:50 PM CDTSevere Thunderstorm WarningOUNMajor25 min
Jul 21, 12:38 AM CDTSevere Thunderstorm WarningOUNCuster, Dewey, Roger Mills67 min
Jul 21, 12:38 AM CDTSevere Thunderstorm WarningOUNGrant, Kay67 min
Jul 21, 12:49 AM CDTSevere Thunderstorm WarningOUNBlaine, Caddo, Canadian, Custer, Dewey, Kingfisher and 1 more71 min
Jul 21, 1:23 AM CDTSevere Thunderstorm WarningOUNGarfield, Grant, Kay, Noble67 min
Jul 21, 1:27 AM CDTSevere Thunderstorm WarningOUNCaddo, Custer, Kiowa, Washita78 min
Jul 21, 2:12 AM CDTSevere Thunderstorm WarningOUNCaddo, Comanche, Cotton, Grady, Kiowa, Stephens and 1 more78 min
Jul 21, 2:55 AM CDTSevere Thunderstorm WarningOUNJackson, Tillman80 min
Jul 21, 3:14 AM CDTSevere Thunderstorm WarningOUNClay, Wichita61 min
Jul 21, 3:30 AM CDTSevere Thunderstorm WarningOUNArcher, Baylor, Clay, Wilbarger90 min

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.