Alert archive / Oklahoma / Tornado Warnings in 1999

Tornado Warning 21, NWS Tulsa, OK

April 21, 1999Osage County, Oklahoma

NWS Tulsa, OK issued this tornado warning at Apr 21, 1999, 10:54 PM CDT for Osage County, Oklahoma. It was in force for 36 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Apr 21, 1999, 10:54 PM CDT (03:54 UTC)
Expired
Apr 21, 1999, 11:30 PM CDT
In force
36 min
Issued by
NWS Tulsa, OK
Area
Whole counties

County Osage County, OK

The watch it was issued in

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

IssuedProductOfficeLasted
Apr 21, 6:00 PM CDTTornado WatchSPC6 hr

The nearest sounding before it

Norman, OK (KOUN), launched 00:00Z, 3.9 hours before the alert went out and 181 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, Norman, OK at 00:00Z on 1999-04-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1907 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Norman, OK at 00:00Z on 1999-04-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 233 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
1907 J/kg
Mixed-layer CIN
-135 J/kg
Mixed-layer LCL
1058 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
233 m²/s²
0-3 km storm-relative helicity
210 m²/s²
Significant tornado parameter
0.9
Supercell composite
5.5

Open this sounding in Storm Lab

The text

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

999 
WFUS54 KTSA 220357 RRA
TORTUL
OKC113-220430-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE TULSA OK
1054 PM CDT WED APR 21 1999

THE NATIONAL WEATHER SERVICE IN TULSA HAS ISSUED A

* TORNADO WARNING FOR
  OSAGE COUNTY IN NORTHEAST OKLAHOMA

* UNTIL 1130 PM CDT

* AT 1054 PM CDT...RADAR INDICATED A SEVERE THUNDERSTORM WITH STRONG 
ROTATION 18 MILES WEST OF HOMINY. MOVING EAST-NORTHEAST AT 25 
MPH...THIS DANGEROUS STORM COULD PRODUCE A TORNADO AT ANY TIME. 

* SOME LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE...  WYNONA AND
  HOMINY

NIGHTTIME TORNADOES ARE ESPECIALLY DANGEROUS - TAKE COVER NOW IF YOU
WAIT UNTIL YOU SEE OR HEAR IT COMING...IT MAY BE TOO LATE TO GET TO A
SAFE PLACE

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

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 21, 10:11 PM CDTSevere Thunderstorm WarningTSAPawnee64 min
Apr 21, 10:44 PM CDTTornado WarningTSAPawnee31 min
Apr 21, 11:29 PM CDTSevere Thunderstorm WarningTSAPawnee46 min
Apr 21, 11:46 PM CDTSevere Thunderstorm WarningTSACreek44 min
Apr 22, 12:07 AM CDTSevere Thunderstorm WarningTSAOsage, Tulsa53 min
Apr 22, 12:30 AM CDTSevere Thunderstorm WarningTSANowata, Rogers, Washington45 min
Apr 22, 1:03 AM CDTSevere Thunderstorm WarningTSACraig, Mayes42 min
Apr 22, 1:22 AM CDTSevere Thunderstorm WarningTSADelaware, Ottawa38 min
Apr 22, 3:07 PM CDTSevere Thunderstorm WarningTSAOsage, Washington38 min
Apr 22, 3:39 PM CDTSevere Thunderstorm WarningTSANowata, Washington36 min
Apr 22, 3:55 PM CDTTornado WarningTSANowata, Washington35 min
Apr 22, 4:25 PM CDTTornado WarningTSACraig35 min
Apr 22, 4:52 PM CDTSevere Thunderstorm WarningTSANowata38 min
Apr 22, 5:01 PM CDTTornado WarningTSACraig29 min
Apr 22, 5:14 PM CDTTornado WarningTSADelaware, Ottawa46 min
Apr 22, 5:27 PM CDTTornado WarningTSACraig33 min
Apr 22, 5:28 PM CDTSevere Thunderstorm WarningTSARogers, Tulsa47 min
Apr 22, 5:37 PM CDTSevere Thunderstorm WarningTSARogers53 min
Apr 22, 5:55 PM CDTSevere Thunderstorm WarningTSAMayes, Rogers, Wagoner50 min
Apr 22, 6:00 PM CDTSevere Thunderstorm WarningTSACraig, Delaware45 min
Apr 22, 6:33 PM CDTTornado WarningTSAMayes, Rogers, Wagoner42 min

Nearby

Tornado Warnings in Oklahoma, 1999Every tornado warning in 1999Tornadoes in 1999

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.