Alert archive / Oklahoma / Tornado Warnings in 2001

Tornado Warning 3, NWS Norman, OK

April 11, 2001Garvin County, McClain County, Oklahoma

NWS Norman, OK issued this tornado warning at Apr 11, 2001, 1:44 AM CDT for Garvin County, McClain County, Oklahoma. It was in force for 31 min. 2 reports came from 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, with what was reported inside it.

The facts

Issued: Apr 11, 2001, 1:44 AM CDT (06:44 UTC)
Expired: Apr 11, 2001, 2:15 AM CDT
In force: 31 min
Issued by: NWS Norman, OK
Area: Whole counties; the outline is the Mesonet’s reconstruction

Counties Garvin County, OK, McClain County, OK

The radar

The Norman radar (KTLX), 55 km from the middle of the area, began a volume at 06:47 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.

What was reported inside it

Time	Report	Where	Remark
Apr 11, 1:47 AM CDT	Thunderstorm Wind	Stratford, OK	Minor damage was sustained to house siding.
Apr 11, 1:50 AM CDT	Thunderstorm Wind	Byars, OK	Large tree limbs were downed.

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Norman, OK (KOUN), launched 00:00Z, 6.7 hours before the alert went out and 46 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: 1767 J/kg
Mixed-layer CIN: -45 J/kg
Mixed-layer LCL: 678 m above ground
0-6 km bulk shear: 63 kt
0-1 km storm-relative helicity: 114 m²/s²
0-3 km storm-relative helicity: 192 m²/s²
Significant tornado parameter: 1.0
Supercell composite: 3.8

Open this sounding in Storm Lab

The text

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

000 
WFUS54 KOUN 110644
TOROKC
OKC049-087-110715-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE NORMAN OK
144 AM CDT WED APR 11 2001

THE NATIONAL WEATHER SERVICE IN NORMAN HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHEAST MCCLAIN COUNTY IN CENTRAL OKLAHOMA
  GARVIN COUNTY IN SOUTHERN OKLAHOMA

* UNTIL 215 AM CDT

* AT 144 AM CDT...DOPPLER RADAR DETECTED A SEVERE THUNDERSTORM
  CAPABLE OF PRODUCING A TORNADO 3 MILES EAST OF PAOLI...MOVING
  NORTHEAST AT 55 MPH.

* LOCATIONS IN THE WARNING INCLUDE BYARS...PAOLI...PAULS VALLEY...
  ROSEDALE...STRATFORD AND WAYNE

TORNADOES ARE ESPECIALLY DANGEROUS AT NIGHT BECAUSE THEY ARE HARD TO
SEE. TAKE COVER NOW. IF A BASEMENT IS NOT AVAILABLE...MOVE TO AN
INTERIOR ROOM OR HALLWAY ON THE LOWEST FLOOR. LEAVE MOBILE HOMES AND
VEHICLES FOR REINFORCED SHELTER. STAY AWAY FROM WINDOWS.

LAT...LON 3486 9738 3471 9727 3475 9695 3490 9693
          3496 9728

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 11, 1:22 AM CDT	Severe Thunderstorm Warning	OUN	Dewey, Woodward	38 min
Apr 11, 1:56 AM CDT	Tornado Warning	OUN	Pottawatomie	34 min
Apr 11, 2:17 AM CDT	Tornado Warning	OUN	Pottawatomie	28 min
Apr 11, 2:56 AM CDT	Tornado Warning	OUN	Pottawatomie, Seminole	34 min
Apr 11, 3:58 AM CDT	Tornado Warning	OUN	Love	32 min
Apr 11, 4:41 AM CDT	Severe Thunderstorm Warning	OUN	Coal, Pontotoc	34 min
Apr 11, 5:05 AM CDT	Severe Thunderstorm Warning	OUN	Atoka, Coal, Johnston	25 min
Apr 11, 5:12 AM CDT	Severe Thunderstorm Warning	OUN	Hughes	33 min
Apr 11, 5:30 AM CDT	Severe Thunderstorm Warning	OUN	Atoka, Bryan	45 min

Nearby

Tornado Warnings in Oklahoma, 2001 Every tornado warning in 2001 Tornadoes 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.