Alert archive / Oklahoma / Tornado Warnings in 2001

Tornado Warning 11, NWS Tulsa, OK

May 20, 2001Washington County, Oklahoma

NWS Tulsa, OK issued this tornado warning at May 20, 2001, 6:41 PM CDT for Washington County, Oklahoma. It was in force for 49 min. 3 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
May 20, 2001, 6:41 PM CDT (23:41 UTC)
Expired
May 20, 2001, 7:30 PM CDT
In force
49 min
Issued by
NWS Tulsa, OK
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Washington County, OK

The radar

The Tulsa radar (KINX), 75 km from the middle of the area, began a volume at 23:41 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

TimeReportWhereRemark
May 20, 6:57 PM CDTThunderstorm Wind 52 EWynona, OK
May 20, 7:11 PM CDTHail 0.75Watova, OK
May 20, 7:15 PM CDTHail 1.75Pawhuska, OK

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.

IssuedProductOfficeLasted
May 20, 5:00 PM CDTSevere Thunderstorm WatchSPC4 hr

The nearest sounding before it

Lamont, OK (KLMN), launched 12:00Z, 11.7 hours before the alert went out and 119 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 12:00Z on 2001-05-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 186 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lamont, OK at 12:00Z on 2001-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 71 square meters per square second.19395878Sfc1 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
186 J/kg
Mixed-layer CIN
-106 J/kg
Mixed-layer LCL
769 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
71 m²/s²
0-3 km storm-relative helicity
125 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 
WFUS54 KTSA 202343
TORTUL

OKC147-210030-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE TULSA OK
641 PM CDT SUN MAY 20 2001

THE NATIONAL WEATHER SERVICE IN TULSA HAS ISSUED A

* TORNADO WARNING FOR...
  WASHINGTON COUNTY IN NORTHEAST OKLAHOMA

* UNTIL 730 PM CDT

* AT 640 PM CDT...DOPPLER RADAR INDICATED A TORNADIC THUNDERSTORM 6
  MILES SOUTHEAST OF PAWHUSKA...MOVING EAST AT 30 MPH. STORM SPOTTERS
  REPORTED A TORNADO ON THE GROUND WITH THIS STORM EARLIER WHEN IT 
  PASSED SOUTH OF PAWHUSKA. THE TORNADO HAD LIFTED MOMENTARILY BUT 
  COULD TOUCH DOWN AGAIN AT ANY TIME. THIS IS A LIFE THREATENING 
  SITUATION...TAKE COVER NOW!

* SOME LOCATIONS NEAR THE PATH OF THIS TORNADO INCLUDE...DEWEY... 
  RAMONA...  OCHELATA...BARTLESVILLE...OKESA.

IF YOU ARE IN OR NEAR THE PATH OF THIS TORNADO...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!

IN ADDITION TO THE TORNADO...LARGE HAIL AND DAMAGING STRAIGHT LINE
WINDS CAN BE EXPECTED WITH THIS STORM. GO TO A SAFE PLACE NOW!

LAT...LON 3670 9638 3652 9634 3655 9581 3685 9581

The office that day

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

IssuedProductOfficeCountiesLasted
May 20, 4:17 PM CDTSevere Thunderstorm WarningTSAOsage58 min
May 20, 4:24 PM CDTSevere Thunderstorm WarningTSAOkfuskee, Okmulgee51 min
May 20, 4:30 PM CDTSevere Thunderstorm WarningTSAMcIntosh60 min
May 20, 4:31 PM CDTTornado WarningTSAMcIntosh29 min
May 20, 4:56 PM CDTTornado WarningTSAMcIntosh49 min
May 20, 5:14 PM CDTSevere Thunderstorm WarningTSAOsage61 min
May 20, 5:23 PM CDTSevere Thunderstorm WarningTSACreek52 min
May 20, 5:32 PM CDTTornado WarningTSAOsage43 min
May 20, 5:45 PM CDTTornado WarningTSAMcIntosh60 min
May 20, 5:46 PM CDTSevere Thunderstorm WarningTSATulsa44 min
May 20, 5:51 PM CDTSevere Thunderstorm WarningTSARogers, Wagoner39 min
May 20, 6:02 PM CDTTornado WarningTSAPittsburg58 min
May 20, 6:11 PM CDTTornado WarningTSAHaskell, Muskogee64 min
May 20, 6:12 PM CDTSevere Thunderstorm WarningTSAOsage48 min
May 20, 6:13 PM CDTSevere Thunderstorm WarningTSAPawnee62 min
May 20, 6:16 PM CDTTornado WarningTSAOsage44 min
May 20, 6:33 PM CDTSevere Thunderstorm WarningTSACraig, Mayes, Rogers57 min
May 20, 6:43 PM CDTSevere Thunderstorm WarningTSACreek, Tulsa62 min
May 20, 6:56 PM CDTTornado WarningTSAMayes49 min
May 20, 6:59 PM CDTSevere Thunderstorm WarningTSAOsage46 min

Nearby

Tornado Warnings in Oklahoma, 2001Every tornado warning in 2001Tornadoes 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.