Alert archive / Oklahoma / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 94, NWS Tulsa, OK

April 20, 1997Muskogee County, Oklahoma

NWS Tulsa, OK issued this severe thunderstorm warning at Apr 20, 1997, 9:11 PM CDT for Muskogee County, Oklahoma. It was in force for 34 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 20, 1997, 9:11 PM CDT (02:11 UTC)
Expired
Apr 20, 1997, 9:45 PM CDT
In force
34 min
Issued by
NWS Tulsa, OK
Area
Whole counties

County Muskogee County, OK

The radar

The Tulsa radar (KINX), 64 km from the middle of the area, began a volume at 02:15 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.

IssuedProductOfficeLasted
Apr 20, 3:45 PM CDTTornado WatchSPC6 hr

The nearest sounding before it

Norman, OK (KOUN), launched 00:00Z, 2.2 hours before the alert went out and 188 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 1997-04-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 490 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 1997-04-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 5 square meters per square second.193958Sfc1 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
490 J/kg
Mixed-layer CIN
-106 J/kg
Mixed-layer LCL
2384 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
5 m²/s²
0-3 km storm-relative helicity
14 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KTUL 210212 RRA
SVRTUL
OKC101-210245-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TULSA OK
911 PM CDT SUN APR 20 1997
 
THE NATIONAL WEATHER SERVICE IN TULSA HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  945 PM CDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN EAST CENTRAL OKLAHOMA
 
   ...SOUTHERN MUSKOGEE COUNTY
 
AT 910 PM WEATHER RADAR INDICATED A SEVERE THUNDERSTORM LOCATED
5 MILES NORTHWEST OF WEBBERS FALLS. MOVEMENT WAS TO THE EAST AT
30 MILES AN HOUR.
 
WEBBERS FALLS AND GORE ARE IN THE PATH OF THIS STORM.
 
HAIL TO THE SIZE OF DIMES AND WIND GUSTS TO 60 MPH CAN BE EXPECTED
IN THE WARNED AREA.
 
KEEP TUNED TO THIS STATION FOR THE LATEST WEATHER BULLETINS.

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Tulsa, OK wrote its last area forecast discussion before this severe thunderstorm warning went out at Apr 20, 8:56 PM CDT, 15 minutes earlier.

Area forecast discussion, Apr 20, 8:56 PM CDT, 15 minutes before
EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
855 PM CDT SUN APR 20 1997

LINE OF STRG/SVR TSRA CONT MVG ACRS ERN PTNS OF FA. THE LINE HAS
MVD OUT AHEAD OF THE WND SHIFT WHICH APRS TO BE JUST S AND E OF
I-44. LOOKS LIKE MESOETA AND 21Z RUC HV FAIRLY GOOD HANDLE ON SFC
FEATURES BUT NOT PRECIP. THUS XPCT TROF TO CONT MVG ACRS ZNS. HV
ALREADY ISSUED ONE UPDATE TO ZFP EARLIER. WL PROB HOLD OFF ON NEXT
UPDATE FOR ANOTHER HR OR TWO UNTIL TSRA GET A LTL FURTHER E. AT
THAT TIME WL ALSO PROB MAKE SOME MINOR ADJS TO MINS AND WNDS AS
WELL.

07

.TUL...
OK...NONE.
AR...NONE.

In the hours before

Local storm report, Apr 20, 7:06 PM CDT, 2 hours 5 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TULSA OK
706 PM CDT SUN APR 20 1997

TIME(CDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0705 PM    2 E TULLAHASSEE           OK   1 INCH HAIL
04/20/97   WAGONER
Special weather statement, Apr 20, 7:28 PM CDT, 1 hour 43 minutes before
OKZ054>076-ARZ001-002-010-011-019-029-211200-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS THUNDERSTORM OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE TULSA OK
730 PM CDT SUN APR 20 1997

NUMEROUS SEVERE THUNDERSTORMS ARE EXPECTED THIS EVENING IN SOUTHEAST
OKLAHOMA AND NORTHWEST ARKANSAS. THE RISK OF SEVERE STORMS IS
SOUTHEAST OF A LINE FROM JAY TO OKEMAH. SEVERE WEATHER WATCHES ARE IN
EFFECT FOR THIS AREA UNTIL LATE EVENING.

A LINE OF STRONG TO SEVERE THUNDERSTORMS HAS ALREADY DEVELOPED ACROSS
EASTERN OKLAHOMA EARLY THIS EVENING. NUMEROUS SEVERE THUNDERSTORM
WARNINGS WERE IN EFFECT AS OF 730 PM ALONG THIS LINE. THE STORMS HAVE
DEVELOPED JUST AHEAD OF A COLD FRONT WHICH WAS MOVING INTO THE AREA.
THE STORMS ARE EXPECTED TO REMAIN SEVERE THIS EVENING AS THEY MOVE
ACROSS SOUTHEAST OKLAHOMA AND NORTHWEST ARKANSAS.

THE GREATEST SEVERE WEATHER THREAT FROM THESE STORMS WILL BE LARGE
HAIL AND DAMAGING WINDS. WIND PROFILES ARE A BIT MORE FAVORABLE FOR
TORNADIC STORMS IN CARROLL AND MADISON COUNTIES OF NORTHWEST
ARKANSAS. CURRENT RADAR INDICATIONS SUGGEST A WEAKNESS IN THE
THUNDERSTORM LINE THAT IS APPROACHING EXTREME NORTHWEST ARKANSAS BUT
SHOULD THE STORMS IN THIS PORTION OF THE LINE INTENSIFY...THE
POTENTIAL WOULD EXIST FOR AN ISOLATED TORNADO IN CARROLL OR MADISON
COUNTIES THIS EVENING.

THE STORMS SHOULD BE EAST OF THE AREA BY MIDNIGHT AND THE SEVERE
WEATHER THREAT WILL END BY THAT TIME.

EMERGENCY MANAGEMENT AGENCIES AND SKYWARN G@ROUPS IN THE RISK AREA
SHOULD ALREADY BE ACTIVATED.
Special weather statement, Apr 20, 7:30 PM CDT, 1 hour 41 minutes before
OKZ054>076-ARZ001-002-010-011-019-029-211200-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS THUNDERSTORM OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE TULSA OK
730 PM CDT SUN APR 20 1997

NUMEROUS SEVERE THUNDERSTORMS ARE EXPECTED THIS EVENING IN SOUTHEAST
OKLAHOMA AND NORTHWEST ARKANSAS. THE RISK OF SEVERE STORMS IS
SOUTHEAST OF A LINE FROM JAY TO OKEMAH. SEVERE WEATHER WATCHES ARE IN
EFFECT FOR THIS AREA UNTIL LATE EVENING.

A LINE OF STRONG TO SEVERE THUNDERSTORMS HAS ALREADY DEVELOPED ACROSS
EASTERN OKLAHOMA EARLY THIS EVENING. NUMEROUS SEVERE THUNDERSTORM
WARNINGS WERE IN EFFECT AS OF 730 PM ALONG THIS LINE. THE STORMS HAVE
DEVELOPED JUST AHEAD OF A COLD FRONT WHICH WAS MOVING INTO THE AREA.
THE STORMS ARE EXPECTED TO REMAIN SEVERE THIS EVENING AS THEY MOVE
ACROSS SOUTHEAST OKLAHOMA AND NORTHWEST ARKANSAS.

THE GREATEST SEVERE WEATHER THREAT FROM THESE STORMS WILL BE LARGE
HAIL AND DAMAGING WINDS. WIND PROFILES ARE A BIT MORE FAVORABLE FOR
TORNADIC STORMS IN CARROLL AND MADISON COUNTIES OF NORTHWEST
ARKANSAS. CURRENT RADAR INDICATIONS SUGGEST A WEAKNESS IN THE
THUNDERSTORM LINE THAT IS APPROACHING EXTREME NORTHWEST ARKANSAS BUT
SHOULD THE STORMS IN THIS PORTION OF THE LINE INTENSIFY...THE
POTENTIAL WOULD EXIST FOR AN ISOLATED TORNADO IN CARROLL OR MADISON
COUNTIES THIS EVENING.

THE STORMS SHOULD BE EAST OF THE AREA BY MIDNIGHT AND THE SEVERE
WEATHER THREAT WILL END BY THAT TIME.

EMERGENCY MANAGEMENT AGENCIES AND SKYWARN GROUPS IN THE RISK AREA
SHOULD ALREADY BE ACTIVATED.
Special weather statement, Apr 20, 8:38 PM CDT, 33 minutes before
OKZ068-070-210215-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TULSA OK
838 PM CDT SUN APR 20 1997

...A SEVERE THUNDERSTORMS WARNING REMAINS IN EFFECT FOR SOUTHERN
CHEROKEE COUNTY UNTIL 900 PM...

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEAST MUSKOGEE COUNTY
HAS BEEN CANCELLED...

AT 835 PM A SEVERE THUNDERSTORM WAS LOCATED NEAR COOKSON IN SOUTHERN
CHEROKEE COUNTY.  MOVMENT WAS TO THE EAST AT 30 MILES AN HOUR AND
WILL AFFECT THE COOKSON AREA AND THE SOUTHERN PART OF THE TENKILLER
LAKE AREA.

DIME TO NICKEL SIZE HAIL AND WIND GUSTS TO 60 MILES AN HOUR REMAIN
POSSIBLE WITH THIS STORM.
Special weather statement, Apr 20, 8:39 PM CDT, 32 minutes before
OKZ068-070-210215-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TULSA OK
838 PM CDT SUN APR 20 1997

...A SEVERE THUNDERSTORMS WARNING REMAINS IN EFFECT FOR SOUTHERN
CHEROKEE COUNTY UNTIL 900 PM...

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEAST MUSKOGEE COUNTY
HAS BEEN CANCELLED...

AT 835 PM A SEVERE THUNDERSTORM WAS LOCATED NEAR COOKSON IN SOUTHERN
CHEROKEE COUNTY.  MOVMENT WAS TO THE EAST AT 30 MILES AN HOUR AND
WILL AFFECT THE fCOOKSON AREA AND THE SOUTHERN PART OF THE TENKILLER
LAKE AREA.

DIME TO NICKEL SIZE HAIL AND WIND GUSTS TO 60 MILES AN HOUR REMAIN
POSSIBLE WITH THIS STORM.
Local storm report, Apr 20, 9:07 PM CDT, 4 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TULSA OK
907 PM CDT SUN APR 20 1997

TIME(CDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0840 PM    COOKSON                   OK   .88 INCH HAIL
04/20/97   CHEROKEE

0858 PM    2 E BEAVER                AR   1.75 INCH HAIL
04/20/97   CARROLL

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 20, 7:01 PM CDTSevere Thunderstorm WarningTSACherokee59 min
Apr 20, 7:09 PM CDTSevere Thunderstorm WarningTSAMcIntosh51 min
Apr 20, 7:26 PM CDTSevere Thunderstorm WarningTSAMuskogee49 min
Apr 20, 8:00 PM CDTSevere Thunderstorm WarningTSAMcIntosh30 min
Apr 20, 8:13 PM CDTSevere Thunderstorm WarningTSACherokee, Muskogee47 min
Apr 20, 8:54 PM CDTSevere Thunderstorm WarningTSASequoyah51 min
Apr 20, 9:39 PM CDTSevere Thunderstorm WarningTSASequoyah36 min
Apr 20, 10:13 PM CDTSevere Thunderstorm WarningTSALeFlore, Sequoyah47 min

Nearby

Severe Thunderstorm Warnings in Oklahoma, 1997Every severe thunderstorm warning in 1997

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.