Alert archive / Oklahoma / Tornado Warnings in 1991

Tornado Warning 49, NWS Norman, OK

May 4, 1991Garvin County, Stephens County, Oklahoma

NWS Norman, OK issued this tornado warning at May 4, 1991, 4:25 PM CDT for Garvin County, Stephens County, Oklahoma. It was in force for 50 min. 3 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
May 4, 1991, 4:25 PM CDT (21:25 UTC)
Expired
May 4, 1991, 5:15 PM CDT
In force
50 min
Issued by
NWS Norman, OK
Area
Whole counties

Counties Garvin County, OK, Stephens County, OK

What was reported inside it

TimeReportWhereRemark
May 4, 4:30 PM CDTHail 1.75Stephens, OK
May 4, 4:58 PM CDTTornado F0Garvin, OK
May 4, 5:20 PM CDTHail 0.88Garvin, 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. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.

The nearest sounding before it

Norman, OK (KOUN), launched 12:00Z, 9.4 hours before the alert went out and 71 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 12:00Z on 1991-05-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 880 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 12:00Z on 1991-05-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 172 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
880 J/kg
Mixed-layer CIN
-166 J/kg
Mixed-layer LCL
601 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
172 m²/s²
0-3 km storm-relative helicity
92 m²/s²
Significant tornado parameter
0.2
Supercell composite
2.3

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KOKC 042127
TOROKC
OKC049-137-042215-
 
BULLETIN - EBS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE OKLAHOMA CITY OK
425 PM CDT SAT MAY 4 1991
 
THE NATIONAL WEATHER SERVICE IN OKLAHOMA CITY HAS ISSUED A
TORNADO WARNING EFFECTIVE UNTIL  515 PM CDT
FOR THE FOLLOWING OKLAHOMA LOCATIONS...
 
IN SOUTHEAST OKLAHOMA
 
   ...WESTERN GARVIN COUNTY
 
IN SOUTHWEST OKLAHOMA
 
   ...EASTERN STEPHENS COUNTY
 
AT 425 PM RADAR INDICATED A POSSIBLE TORNADO NEAR VELMA MOVING TO THE
NORTHEAST AT 20 MPH. A LARGE SEVERE THUNDERSTORM OVER EASTERN STEPHENS
COUNTY WILL MOVE INTO GARVIN COUNTY WITH HAIL UP TO BASEBALL SIZE
POSSIBLE.
 
THIS IS A DANGEROUS STORM SITUATION.  ACT QUICKLY.  IF YOU ARE
IN THE PAT+H OF THIS TORNADO MOVE TO A SHELTER BELOW GROUND IF
AVAILABLE.  OTHERWISE...GO TO A SMALL INTERIOR ROOM ON THE LOWEST
FLOOR POSSIBLE.  AVOID WINDOWS.  ABANDON CARS AND MOBILE HOMES
FOR A REINFORCED BUILDING OR GET INTO A DITCH OR CULVERT.

What forecasters said that day

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

In the hours before

Special weather statement, May 4, 12:06 PM CDT, 4 hours 19 minutes before
TXZ020-019-041800-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WICHITA FALLS TX
1200 PM CDT SAT MAY 4 1991

...SEVERE THUNDERSTORM WATCH IN EFFECT UNTIL 300 PM CDT THIS AFTERNOON
FOR THE FOLLOWING NORTH CENTRAL TEXAS COUNTIES YOUNG AND JACK...

AT NOON RADAR SHOWED THUNDERSTORMS DEVLOPING RAPIDLY FROM NORTHEAST AND
EAST OF ABILENE EXTENDING SOUTH TO SAN ANGELO. MOVEMENT OF THUNDERSTORMS
TO THE NORTHEAST AT 35 MPH.

THUNDERSTORMS...SOME SEVERE...WILL CONTINUE TO BUILD NORTH ALONG THE DRY
LINE SHORTLY. RESIDENTS OF YOUNG COUNTY CAN EXPECT THUNDERSTORMS TO
BEGIN MOVING INTO THE AREA SHORTLY AFTER 100 PM THIS AFTERNOON.  .

RESIDENTS ACROSS THIS PORTION OF NORTH CENTRAL TEXAS...ESPECIA0LLY YOUNG
COUNTY...SHOULD KEEP ABREAST OF THE LATEST WEATHER CONDITIONS AND BE
PREPARED TO TAKE ACTION SHOULD SEVERE WEATHER BE SIGHTED OR WARNING
ISSUED.
Special weather statement, May 4, 12:14 PM CDT, 4 hours 11 minutes before
TXZ020-019-041800-

SPECIAL WEATHER STATEMENT...CORRECTION
NATIONAL WEATHER SERVICE WICHITA FALLS TX
1210 PM CDT SAT MAY 4 1991

...SEVERE THUNDERSTORM WATCH IN EFFECT UNTIL 300 PM CDT THIS AFTERNOON
FOR THE FOLLOWING NORTH CENTRAL TEXAS COUNTIES YOUNG AND JACK...

AT NOON RADAR SHOWED THUNDERSTORMS DEVLOPING RAPIDLY FROM WEST OF YOUNG
COUNTY EXTENDING SOUTH TO EAST OF ABILENE TO SAN ANGELO. MOVEMENT OF
THUNDERSTORMS TO THE NORTHEAST 35 MPH.

THUNDERSTORMS...SOME SEVERE...WILL CONTINUE TO BUILD NORTH ALONG THE DRY
LINE SHORTLY. RESIDENTS OF YOUNG COUNTY CAN EXPECT THUNDERSTORMS TO
BEGIN MOVING INTO THE AREA IN THE NEXT 10 MINUTES.

RESIDENTS ACROSS THIS PORTION OF NORTH CENTRAL TEXAS...ESPECIALLY YOUNG
COUNTY...SHOULD KEEP ABREAST OF THE LATEST WEATHER CONDITIONS AND BE
PREPARED TO TAKE ACTION SHOULD SEVERE WEATHER BE SIGHTED OR WARNING
ISSUED.
Special weather statement, May 4, 1:03 PM CDT, 3 hours 22 minutes before
OKZ004>021-051200-

OKLAHOMA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE OKLAHOMA CITY OK
1245 PM CDT SAT MAY 4 1991

THIS THUNDERSTORM OUTLOOK IS VALID ONLY FOR OKLAHOMA ZONES 4 THROUGH
21. A THUNDERSTORM OUTLOOK FOR THE OKLAHOMA AND TEXAS PANHANDLES IS
AVAILABLE UNDER LBBSPSAMA...AND A THUNDERSTORM OUTLOOK FOR EASTERN
OKLAHOMA IS AVAILABLE UNDER OKCSPSTUL.

THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON OVER
MUCH OF NORTHERN AND WESTERN OKLAHOMA AND TONIGHT OVER THE CENTRAL AND
EASTERN SECTIONS OF THE STATE. THE MODERATE RISK AREA IS GENERALLY
EAST OF A LINE FROM ALTUS TO CORDELL TO ALVA.  THERE IS A SLIGHT RISK OF
SEVERE THUNDERSTORMS OVER THE REMAINDER OF WESTERN OKLAHOMA EAST OF THE
PANHANDLE LATE THROUGH TONIGHT.

A SURFACE LOW PRESSURE SYSTEM WAS CENTERED OVER NORTHWESTERN OKLAHOMA
LATE THIS MORNING.  A STATIONARY FRONT EXTENDED FROM CENTRAL MISSOURI
INTO EASTERN KANSAS THROUGH NORTHWESTERN OKLAHOMA TO THE LOW PRESSURE
SYSTEM... THEN NORTHWESTWARD INTO COLORADO.  A DRYLINE EXTENDS SOUTH
FROM THE LOW PRESSURE SYSTEM ALONG THE OKLAHOMA-TEXAS BORDER INTO
CENTRAL TEXAS.

A NUMBER OF FACTORS ARE COMING TOGETHER TO SUPPORT A SIGNIFICANT
SEVERE WEATHER EVENT IN OKLAHOMA TODAY. MOIST GULF AIR WITH DEWPOINTS IN
THE 60S COVERS MUCH OF THE STATE. THE ATMOSPHERE OVER OKLAHOMA WILL
CONTINUE TO DESTABILIZE AS COOL MID LEVEL AIR IS ADVECTED OVER THE LOW
LEVEL MOISTURE. THE LOW PRESSURE SYSTEM WILL MOVE EASTWARD ALONG THE
FRONTAL BOUNDARY AS A VIGOROUS UPPER LEVEL TROUGH OVER THE
SOUTHWESTERN STATES APPROACHES OKLAHOMA AND THE DRYLINE WILL
ENTER THE WESTERN PORTIONS OF THE STATE.  SURFACE HEATING WILL
FURTHER DESTABILIZE THE ATMOSPHERE.  BOTH THE DRYLINE AND FRONTAL
BOUNDARY WILL ACT AS FOCUSING MECHANISMS FOR THUNDERSTORM
DEVELOPMENT AND SOME OF THESE THUNDERSTORMS ARE LIKELY TO BECOME
SEVERE.  ADDITIONAL ISOLATED SEVERE THUNDERSTORMS COULD DEVELOP IN
ADVANCE OF THE DRYLINE LATER THIS AFTERNOON.

WINDS WILL INCREASE ALOFT WITH THE APPROACH OF THE UPPER LEVEL
TROUGH..CREATING A FAVORABLE WIND PROFILE FOR TORNADO DEVELOPMENT...
ESPECIALLY ACROSS THE NORTHWESTERN AND NORTHCENTRAL SECTIONS OF THE
STATE.

AS THE UPPER LEVEL TROUGH MOVES NORTHEASTWARD INTO THE CENTRAL US
TONIGHT A COLD FRONT WILL ADVANCE ACROSS WESTERN OKLAHOMA.  A LINE OF
INTENSE THUNDERSTORMS WILL DEVELOP ALONG THE FRONT THIS EVENING AND
PROGRESS EASTWARD ACROSS THE STATE BEFORE SUNRISE ON SUNDAY.

SPOTTER ORGqANIZATIONS ACROSS CENTRAL AND WESTERN OKLAHOMA SHOULD REMAIN
ALERT FOR POSSIBLE ACTIVATION THIS AFTERNOON.
Local storm report, May 4, 4:21 PM CDT, 4 minutes before
LOCAL STORM REPORT
NATIONAL WEATHER SERVICE WICHITA FALLS TX
415 PM CDT SAT MAY 04 1991

TIME         COUNTY       EVENT

115 PM       JACK         PEA TO MARBLE SIZE HAIL SW OF GRAHAM

326 PM       YOUNG        MARBLE SIZE HAIL REPORTED 4MI W OF LOVING
                          IN YOUNG COUNTY

342 PM CDT   YOUNG        MARBLE TO DIME SIZE HAIL BETWEEN JEAN AND
                          FARMER.

The office that day

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

IssuedProductOfficeCountiesLasted
May 4, 3:32 PM CDTSevere Thunderstorm WarningOUNStephens43 min
May 4, 4:04 PM CDTTornado WarningOUNStephens26 min
May 4, 4:45 PM CDTSevere Thunderstorm WarningOUNJefferson45 min
May 4, 4:49 PM CDTSevere Thunderstorm WarningOUNGarfield41 min
May 4, 5:10 PM CDTSevere Thunderstorm WarningOUNGrant50 min
May 4, 5:19 PM CDTSevere Thunderstorm WarningOUNKay41 min
May 4, 5:48 PM CDTSevere Thunderstorm WarningOUNKingfisher, Logan42 min
May 4, 6:08 PM CDTSevere Thunderstorm WarningOUNCleveland, Oklahoma52 min
May 4, 6:34 PM CDTSevere Thunderstorm WarningOUNLincoln, Oklahoma41 min
May 4, 6:40 PM CDTSevere Thunderstorm WarningOUNGarfield50 min
May 4, 6:58 PM CDTSevere Thunderstorm WarningOUNCaddo, Canadian, Grady47 min
May 4, 6:58 PM CDTSevere Thunderstorm WarningOUNKingfisher47 min

Nearby

Tornado Warnings in Oklahoma, 1991Every tornado warning in 1991Tornadoes in 1991

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.