Alert archive / Oklahoma / Tornado Warnings in 2001

Tornado Warning 1, NWS Tulsa, OK

April 11, 2001Haskell County, Sequoyah County, Oklahoma

NWS Tulsa, OK issued this tornado warning at Apr 11, 2001, 7:28 AM CDT for Haskell County, Sequoyah County, Oklahoma. It was in force for 47 min. 1 report 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, 7:28 AM CDT (12:28 UTC)
Expired: Apr 11, 2001, 8:15 AM CDT
In force: 47 min
Issued by: NWS Tulsa, OK
Area: Whole counties; the outline is the Mesonet’s reconstruction

Counties Haskell County, OK, Sequoyah County, OK

What was reported inside it

Time	Report	Where	Remark
Apr 11, 7:41 AM CDT	Thunderstorm Wind	Vian, OK	Thunderstorm winds blew the roof off a barn and downed several trees and power lines from west of Vian to near Box.

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 watch it was issued in

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

Issued	Product	Office	Lasted
Apr 11, 6:15 AM CDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Springfield, MO (KSGF), launched 12:00Z, 0.5 hours before the alert went out and 200 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: 614 J/kg
Mixed-layer CIN: -13 J/kg
Mixed-layer LCL: 815 m above ground
0-6 km bulk shear: 67 kt
0-1 km storm-relative helicity: 256 m²/s²
0-3 km storm-relative helicity: 270 m²/s²
Significant tornado parameter: 1.1
Supercell composite: 4.4

Open this sounding in Storm Lab

The text

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

000 
WFUS54 KTSA 111228
TORTUL
OKC061-135-111315-

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

THE NATIONAL WEATHER SERVICE IN TULSA HAS ISSUED A

* TORNADO WARNING FOR
  SEQUOYAH COUNTY IN EAST CENTRAL OKLAHOMA
  NORTHEASTERN HASKELL COUNTY IN SOUTHEAST OKLAHOMA

* UNTIL 815 AM CDT

* AT 728 AM CDT...DOPPLER RADAR INDICATED A DEVELOPING TORNADO 9
  MILES SOUTHWEST OF TAMAHA. THIS DANGEROUS STORM IS MOVING NORTHEAST
  AT 55 MPH.

* SOME LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE...VIAN...
  SALLISAW AND TAMAHA.

IF YOU ARE IN OR NEAR THE PATH OF THIS STORM...TAKE COVER NOW! IF NO
UNDERGROUND SHELTER IS AVAILABLE MOVE TO AN INTERIOR ROOM ON THE
LOWEST FLOOR. MOBILE HOMES AND VEHICLES SHOULD BE ABANDONED FOR MORE
SUBSTANTIAL SHELTER. AVOID WINDOWS!

DO NOT TAKE SHELTER UNDER HIGHWAY OVERPASSES!

LAT...LON 3534 9518 3522 9510 3543 9469 3565 9496

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 11, 5:22 AM CDT	Severe Thunderstorm Warning	TSA	McIntosh, Pittsburg	53 min
Apr 11, 5:22 AM CDT	Severe Thunderstorm Warning	TSA	Okfuskee, Okmulgee	53 min
Apr 11, 5:55 AM CDT	Severe Thunderstorm Warning	TSA	Choctaw, Pushmataha	50 min
Apr 11, 6:14 AM CDT	Severe Thunderstorm Warning	TSA	Haskell, Latimer, Pittsburg	46 min
Apr 11, 6:14 AM CDT	Severe Thunderstorm Warning	TSA	McIntosh	46 min
Apr 11, 6:40 AM CDT	Severe Thunderstorm Warning	TSA	Choctaw, Pushmataha	65 min
Apr 11, 6:53 AM CDT	Severe Thunderstorm Warning	TSA	Haskell, Muskogee, Sequoyah	52 min
Apr 11, 6:53 AM CDT	Severe Thunderstorm Warning	TSA	McIntosh	52 min
Apr 11, 6:53 AM CDT	Severe Thunderstorm Warning	TSA	Latimer	52 min
Apr 11, 7:20 AM CDT	Severe Thunderstorm Warning	TSA	Mayes, Wagoner	40 min
Apr 11, 7:26 AM CDT	Severe Thunderstorm Warning	TSA	LeFlore	64 min
Apr 11, 7:33 AM CDT	Severe Thunderstorm Warning	TSA	Cherokee	27 min
Apr 11, 7:44 AM CDT	Severe Thunderstorm Warning	TSA	Sequoyah	46 min
Apr 11, 7:53 AM CDT	Severe Thunderstorm Warning	TSA	Adair, Cherokee, Delaware	52 min
Apr 11, 7:53 AM CDT	Severe Thunderstorm Warning	TSA	Craig, Mayes, Ottawa	52 min
Apr 11, 8:27 AM CDT	Severe Thunderstorm Warning	TSA	LeFlore	63 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.