Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 621, NWS Norman, OK

October 9, 2001Cleveland County, McClain County, Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at Oct 9, 2001, 8:10 PM CDT for Cleveland County, McClain County, Oklahoma. It was in force for 50 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties.

The facts

Issued: Oct 9, 2001, 8:10 PM CDT (01:10 UTC)
Expired: Oct 9, 2001, 9:00 PM CDT
In force: 50 min
Issued by: NWS Norman, OK
Area: Whole counties; the outline is the Mesonet’s reconstruction

Counties Cleveland County, OK, McClain County, OK

The radar

The Norman radar (KTLX), 26 km from the middle of the area, began a volume at 01:09 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.

Issued	Product	Office	Lasted
Oct 9, 5:30 PM CDT	Tornado Watch	SPC	4 hr

The nearest sounding before it

Norman, OK (KOUN), launched 00:00Z, 1.2 hours before the alert went out and 15 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: 1756 J/kg
Mixed-layer CIN: -24 J/kg
Mixed-layer LCL: 567 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: 413 m²/s²
0-3 km storm-relative helicity: 448 m²/s²
Significant tornado parameter: 4.3
Supercell composite: 15.8

Open this sounding in Storm Lab

The text

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

242 
WUUS54 KOUN 100108
SVROKC
OKC027-087-100200-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE NORMAN OK
810 PM CDT TUE OCT 9 2001

THE NATIONAL WEATHER SERVICE IN NORMAN HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CLEVELAND COUNTY IN CENTRAL OKLAHOMA
  MCCLAIN COUNTY IN CENTRAL OKLAHOMA

* UNTIL 900 PM CDT

* AT 810 PM CDT...DOPPLER RADAR DETECTED A SEVERE THUNDERSTORM 8   
MILES WEST OF NEWCASTLE...MOVING NORTHEAST AT 30 MPH.

* LOCATIONS IN THE WARNING INCLUDE MOORE...NEWCASTLE... SOUTHWEST 
OKLAHOMA CITY AND NORMAN

HAIL UP TO THE SIZE OF QUARTERS AND 60 MPH WINDS ARE LIKELY WITH 
THIS SEVERE THUNDERSTORM.

THIS THUNDERSTORM HAS SHOWN VERY STRONG ROTATION IN NORTHERN GRADY 
COUNTY AND IS BEING MONITORED FOR A POSSIBLE UPGRADE TO A TORNADO 
WARNING FOR CLEVELAND AND MCCLAIN COUNTIES. 

SEVERE THUNDERSTORMS CAN PRODUCE TORNADOES WITH NO ADVANCE WARNING. 
MOVE IMMEDIATELY TO A STORM SHELTER... BASEMENT OR STURDY BUILDING IF
A TORNADO IS SIGHTED.

LAT...LON 3533 9767 3514 9765 3513 9734 3537 9732
          3538 9767
CJS

The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 9, 7:13 PM CDT	Tornado Warning	OUN	Caddo	32 min
Oct 9, 7:34 PM CDT	Tornado Warning	OUN	Grady	41 min
Oct 9, 7:45 PM CDT	Severe Thunderstorm Warning	OUN	Caddo	30 min
Oct 9, 7:54 PM CDT	Severe Thunderstorm Warning	OUN	Canadian	51 min
Oct 9, 8:17 PM CDT	Tornado Warning	OUN	Grady, McClain	28 min
Oct 9, 8:46 PM CDT	Tornado Warning	OUN	Cleveland, McClain	29 min
Oct 9, 8:47 PM CDT	Tornado Warning	OUN	Grady	43 min
Oct 9, 8:52 PM CDT	Severe Thunderstorm Warning	OUN	Canadian	38 min
Oct 9, 9:13 PM CDT	Tornado Warning	OUN	Cleveland, McClain	32 min
Oct 9, 9:41 PM CDT	Severe Thunderstorm Warning	OUN	Cleveland, Oklahoma	49 min
Oct 9, 10:32 PM CDT	Severe Thunderstorm Warning	OUN	Lincoln, Oklahoma	43 min
Oct 10, 12:45 PM CDT	Severe Thunderstorm Warning	OUN	Garvin, Pontotoc	45 min

Nearby

Severe Thunderstorm Warnings in Oklahoma, 2001 Every severe thunderstorm warning in 2001

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.