Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 38, NWS Norman, OK

April 11, 2002Grant County, Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at Apr 11, 2002, 9:07 PM CDT for Grant County, Oklahoma. It was in force for 53 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Apr 11, 2002, 9:07 PM CDT (02:07 UTC)
Expired: Apr 11, 2002, 10:00 PM CDT
In force: 53 min
Issued by: NWS Norman, OK
Area: Counties, with a storm outline in the text

County Grant County, OK

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Norman, OK (KOUN), launched 00:00Z, 2.1 hours before the alert went out and 183 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: 321 J/kg
Mixed-layer CIN: -127 J/kg
Mixed-layer LCL: 1517 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 71 m²/s²
0-3 km storm-relative helicity: 188 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WUUS54 KOUN 120207
SVROKC
OKC053-120300-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE NORMAN OK
906 PM CDT THU APR 11 2002

THE NATIONAL WEATHER SERVICE IN NORMAN HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  GRANT COUNTY IN NORTHERN OKLAHOMA

* UNTIL 1000 PM CDT

* AT 906 PM CDT...DOPPLER RADAR DETECTED A SEVERE THUNDERSTORM 10
  MILES NORTH OF WAKITA...MOVING SOUTHEAST AT 20 MPH.

* LOCATIONS IN THE WARNING INCLUDE DEER CREEK...JEFFERSON...LAMONT...
  MEDFORD...NASH...POND CREEK...RENFROW AND WAKITA

HAIL UP TO 1.5 INCHES IN DIAMETER IS LIKELY WITH THIS SEVERE 
THUNDERSTORM. WINDS OVER 70 MILES AN HOUR ARE POSSIBLE WITH THIS 
STORM.

THESE THUNDERSTORMS ARE CAPABLE OF PRODUCING PARTICULARLY DAMAGING
WINDS. MOBILE HOMES AND HIGH PROFILE VEHICLES ARE ESPECIALLY
SUSCEPTIBLE TO HIGH WINDS AND MAY BE OVERTURNED. MOVE TO A STURDY
BUILDING AND STAY AWAY FROM WINDOWS.

LAT...LON 3700 9750 3699 9809 3660 9807 3663 9749

WR

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 Apr 11, 8:30 PM CDT, 37 minutes earlier.

Area forecast discussion, Apr 11, 8:30 PM CDT, 37 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
830 PM CDT THU APR 11 2002

ACTIVITY HAS STRUGGLED TO DEVELOP ACROSS THE AREA THIS EVENING AS
WARM MID LEVEL TEMPS HAS KEPT THINGS IN CHECK SO FAR ACROSS MOST OF
THE AREA. STILL THINK WE MAY SEE SOME ADDITIONAL DEVELOPMENT ACROSS
AREA OVERNIGHT AS MAIN SFC BOUNDARY REMAINS ACROSS FAR NORTHWEST
OKLAHOMA AND THE POTENTIAL FOR STRONGER LOW LEVEL JET TO DEVELOP
THAN IS FORECAST BY MODELS. MOST MODELS SHOWED MORE ACTIVITY AND
THEREFORE HAD THE SFC BOUNDARY PUSHING FARTHER SOUTHEAST THIS
EVENING. SEVERE POTENTIAL LOOKS TO BE DIMINISHED ACROSS MUCH OF AREA
HOWEVER AS WE LOSE AFTN HEATING AND MAIN UPPER WAVE WORKS ON TO THE
NE OF AREA. WILL LIKELY REMOVE SEVERE WORDING EVERYWHERE EXCEPT
ACROSS PORTIONS OF NORTH AND WILL LOWER POPS SLIGHTLY AS WELL.
WITH SLOWER PROGRESSION OF SFC BOUNDARY WITH MAKE SOME ADJUSTMENTS
TO WINDS. TEMPS LOOK TO BE ON TRACK. UPDATES OUT SHORTLY.

30

.OUN...
OK...NONE.
TX...NONE.

In the hours before

Local storm report, Apr 11, 6:25 PM CDT, 2 hours 42 minutes before

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
625 PM CDT THU APR 11 2002

TIME (CDT) .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0615 PM    PECKHAM                   OK   .88 INCH HAIL
04/11/02   KAY                            REPORTED BY SPOTTER

Local storm report, Apr 11, 6:50 PM CDT, 2 hours 17 minutes before

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
650 PM CDT THU APR 11 2002

TIME (CDT) .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0640 PM    4.5 E OF BLACKWELL        OK   .75 INCH HAIL
04/11/02   KAY                            REPORTED BY SPOTTER

Local storm report, Apr 11, 7:03 PM CDT, 2 hours 4 minutes before

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
703 PM CDT THU APR 11 2002

TIME (CDT) .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0653 PM    0.5 S KILDARE             OK   1.00 INCH HAIL
                                          ON HWY 77
04/11/02   KAY                            REPORTED BY PUBLIC

Local storm report, Apr 11, 7:07 PM CDT, 2 hours before

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
707 PM CDT THU APR 11 2002

TIME (CDT) .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0700 PM    KILDARE                   OK   .75 INCH HAIL
04/11/02   KAY                            REPORTED BY SPOTTER

0703 PM    KILDARE                   OK   1.00 INCH HAIL
04/11/02   KAY                            REPORTED BY SPOTTER

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 11, 7:15 PM CDT	Severe Thunderstorm Warning	OUN	Kay	45 min
Apr 11, 10:28 PM CDT	Severe Thunderstorm Warning	OUN	Grant	47 min
Apr 11, 10:39 PM CDT	Flash Flood Warning	OUN	Grant	3 hr
Apr 11, 10:44 PM CDT	Tornado Warning	OUN	Garfield, Grant	31 min
Apr 11, 11:00 PM CDT	Tornado Warning	OUN	Garfield, Noble	30 min
Apr 11, 11:02 PM CDT	Severe Thunderstorm Warning	OUN	Kay	43 min
Apr 11, 11:32 PM CDT	Tornado Warning	OUN	Garfield, Noble	28 min
Apr 12, 5:32 AM CDT	Severe Thunderstorm Warning	OUN	Dewey, Woodward	43 min
Apr 12, 5:37 AM CDT	Severe Thunderstorm Warning	OUN	Ellis	38 min
Apr 12, 6:18 AM CDT	Severe Thunderstorm Warning	OUN	Dewey, Ellis	27 min
Apr 12, 7:59 AM CDT	Severe Thunderstorm Warning	OUN	Custer	31 min
Apr 12, 8:21 AM CDT	Severe Thunderstorm Warning	OUN	Beckham	24 min
Apr 12, 8:34 AM CDT	Severe Thunderstorm Warning	OUN	Greer, Kiowa	41 min
Apr 12, 9:14 AM CDT	Severe Thunderstorm Warning	OUN	Kiowa	46 min
Apr 12, 9:22 AM CDT	Severe Thunderstorm Warning	OUN	Caddo	38 min
Apr 12, 9:43 AM CDT	Severe Thunderstorm Warning	OUN	Comanche	62 min
Apr 12, 9:58 AM CDT	Severe Thunderstorm Warning	OUN	Caddo, Grady	47 min
Apr 12, 10:41 AM CDT	Severe Thunderstorm Warning	OUN	Comanche, Cotton, Grady, Stephens	49 min
Apr 12, 11:26 AM CDT	Severe Thunderstorm Warning	OUN	Carter, Jefferson, Stephens	49 min
Apr 12, 12:11 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Jefferson, Love	34 min
Apr 12, 12:44 PM CDT	Severe Thunderstorm Warning	OUN	Love	61 min
Apr 12, 1:32 PM CDT	Severe Thunderstorm Warning	OUN	Stephens	28 min
Apr 12, 1:46 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Jefferson	44 min
Apr 12, 4:25 PM CDT	Severe Thunderstorm Warning	OUN	Stephens	50 min
Apr 12, 5:29 PM CDT	Severe Thunderstorm Warning	OUN	Carter	46 min

Nearby

Severe Thunderstorm Warnings in Oklahoma, 2002 Every severe thunderstorm warning in 2002

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.