Alert archive / Oklahoma / Tornado Warnings in 1990

Tornado Warning 15, NWS Norman, OK

April 9, 1990Harper County, Oklahoma

NWS Norman, OK issued this tornado warning at Apr 9, 1990, 6:12 PM CDT for Harper County, Oklahoma. It was in force for 33 min. 1 report 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
Apr 9, 1990, 6:12 PM CDT (23:12 UTC)
Expired
Apr 9, 1990, 6:45 PM CDT
In force
33 min
Issued by
NWS Norman, OK
Area
Whole counties

County Harper County, OK

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

What was reported inside it

TimeReportWhereRemark
Apr 9, 6:25 PM CDTHail 0.88Harper, 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

Dodge City, (KDDC), launched 12:00Z, 11.2 hours before the alert went out and 111 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, Dodge City, at 12:00Z on 1990-04-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Dodge City, at 12:00Z on 1990-04-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 214 square meters per square second.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1469 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
214 m²/s²
0-3 km storm-relative helicity
248 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 KOKC 092315
TOROKC
OKC059-092345-
 
BULLETIN - EBS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE OKLAHOMA CITY OK
612 PM CDT MON APR 9 1990
 
THE NATIONAL WEATHER SERVICE IN OKLAHOMA CITY HAS ISSUED A
TORNADO WARNING EFFECTIVE UNTIL  645 PM CDT
FOR THE FOLLOWING OKLAHOMA LOCATIONS...
 
IN NORTHWEST OKLAHOMA
 
   ...HARPER COUNTY
 
AT 612 PM CDT RADAR INDICATED A TORNADO 10 MILES SOUTH OF BUFFALO
MOVING TO THE EAST AT 20 MPH.
 
THIS IS A DANGEROUS STORM AND YOU SHOULD TAKE COVER AS IT APPROACHES.
DO NOT USE YOUR CAR TO TRY TO OUTRUN A TORNADO.  CARS ARE EASILY
TOSSED AROUND BY TORNADO WINDS.  IF YOU ARE CAUGHT IN THE PATH OF
A TORNADO...LEAVE THE CAR AND GO TO A STRONG BUILDING.  IF NO
STRUCTURE IS NEARBY...SEEK SHELTER IN A DITCH OR LOW SPOT.

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, Apr 9, 1:06 PM CDT, 5 hours 6 minutes before
OKZALL-101200-
OKLAHOMA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE OKLAHOMA CITY OK
100 PM CDT MON APR 9 1990

...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS TODAY AND TONIGHT
   FOR WESTERN OKLAHOMA...EXCLUDING THE PANHANDLE...WEST OF A LINE FROM
   MARIETTA TO BLACKWELL...
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR EASTERN OKLAHOMA...
   EAST OF A LINE FROM MARIETTA TO BLACKWELL...

RICH MOISTURE CONTINUED TO STREAM NORTHWARD TODAY WITH THE MAIN AXIS OF
MOISTURE ACROSS CENTRAL OKLAHOMA. A DRY LINE WAS ESTABLISHED FROM KANSAS
SOUTH ACROSS THE TEXAS PANHANDLE. WIDESPREAD CLOUDINESS OVER MUCH OF
THE STATE PERSISTED THROUGH THIS MORNING AND WAS SLOWLY DISSIPATING OVER
NORTHWESTERN SECTIONS. A VIGOROUS UPPER LEVEL SYSTEM WAS LOCATED OVER
WESTERN COLORADO AND ARIZONA AND WAS MOVING EASTWARD. A COLD FRONT WAS
LOCATED OVER NORTHWESTERN KANSAS MOVING SOUTHWARD.

AS THE UPPER LEVEL SYSTEM APPROACHES OKLAHOMA FROM THE WEST AND ENCOUNTERS
THE DRY LINE...THUNDERSTORMS WILL DEVELOP OVER WESTERN SECTIONS OF THE
STATE. CURRENT INFORMATION INDICATES THAT THE STORMS OVER THE WESTERN
PORTIONS OF THE STATE COULD PRODUCE LARGE HAIL AND TORNADOES. THESE
STORMS ARE EXPECTED TO DEVELOP EARLY THIS AFTERNOON.

AS THE UPPER LEVEL SYSTEM MOVES EASTWARD AND THE FRONT MOVES SOUTHWARD...
THUNDERSTORMS WILL MOVE EASTWARD ACROSS THE STATE. THE ACTIVITY WILL
CONTINUE INTO THE NIGHTTIME HOURS WITH PRESENT INDICATIONS THAT THE
EASTERN HALF OF THE STATE CAN EXPECT  MAINLY LARGE HAIL AND HEAVY
RAINFALL. WITH THE FRONTAL BOUNDARY MOVING ACROSS THE STATE AND LOCATED
OVER EASTERN SECTIONS...THUNDERSTORMS MAY REPEATEDLY MOVE OVER THE SAME
AREAS...CAUSING LOCALIZED FLASH FLOODING.

SPOTTER GROUPS AND CIVIL DEFENSE AGENCIES OVER MOST SECTIONS OF THE
STATE EXCEPT THE PANHANDLE SHOULD BE ALERT AND PREPARED FOR ACTIVATION
LATER THIS AFTERNOON AND TONIGHT.
Special weather statement, Apr 9, 3:40 PM CDT, 2 hours 32 minutes before
TXZALL-092145-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WICHITA FALLS TX
340 PM CDT MON APR 9 1990

...TORNADO WATCH HAS BEEN ISSUED FOR PARTS OF SOUTHWEST AND SOUTH
CENTRAL OKLAHOMA AND A LARGE PORTION OF NORTHWEST TEXAS UNTIL 10 PM
CDT THIS MONDAY EVENING...

COUNTIES INCLUDED IN THIS PORTION OF NORTH CENTRAL TEXAS INCLUDE
ARCHER..BAYLOR..CLAY..FOARD..HARDEMAN..JACK..KNOX..WICHITA..WILBARGER.AND YOUNG. THIS INCLUDES COTTON COUNTY OF SOUTHWESTERN OKLAHOMA.

AT 330 PM CDT RADAR INDICATED AN AREA OF RAPIDLY DEVELOPING
THUNDERSTORMS IN SOUTHWESTERN OKLAHOMA FROM NORTH OF CHILDRESS TEXAS
NORTHEASTWARD TO OKLAHOMA CITY. MOVEMENT WAS NORTHEAST AT 30 MPH.
NO THUNDERSTORMS WERE INDICATED ON RADAR IN THIS PORTION OF NORTH
CENTRAL TEXAS BUT ARE EXPECTED TO FORM AND BUILD RAPIDLY THIS
AFTERNOON AND EVENING.

REMEMBER A TORNADO WATCH MEANS THAT CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA.
PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING
WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE
WARNINGS.
Special weather statement, Apr 9, 4:42 PM CDT, 1 hour 30 minutes before
TXZALL-092245-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WICHITA FALLS TX
442 PM CDT MON APR 9 1990

...TORNADO WATCH IS IN EFFECT UNTIL 10 PM CDT THIS MONDAY EVENING FOR
A LARGE PORTION OF NORTHWESTERN TEXAS AND PORTIONS OF SOUTHWESTERN AND
SOUTH CENTRAL OKLAHOMA...

AT 430 PM CDT RADAR INDICATED THUNDERSTORMS WERE RAPIDLY FORMING
ACROSS THE AREA. IN OKLAHOMA THE STRONGEST THUNDERSTORM WAS NEAR
DUNCAN. IN TEXAS THUNDERSTORMS WERE DEVELOPING FROM SOUTHWEST OF
WICHITA FALLS TO ABILENE. THE STRONGEST THUNDERSTORMS WERE ENTERING
SOUTHERN ARCHER COUNTY AND SHOULD MOVE SOUTHEAST OF ARCHER CITY.
MOVEMENT WAS NORTHEAST AT 25 MPH.

REMEMBER A TORNADO WATCH MEANS THAT CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS TO DEVELOP IN AND NEAR THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE ALERT FOR THREATENING
WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS OR POSSIBLE
WARNINGS.
Special weather statement, Apr 9, 5:34 PM CDT, 38 minutes before
TXZALL-092330-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WICHITA FALLS TX
534 PM CDT MON APR 9 1990

...TORNADO WATCH IS IN EFFECT UNTIL 10 PM CDT THIS MONDAY AFTERNOON
AND EVENING FOR THIS PORTION OF NORTH CENTRAL TEXAS AND SOUTHWESTERN
OKLAHOMA...

AT 530 CDT RADAR INDICATED A FEW THUNDERSHOWERS..DECREASING IN
INTENSITY..ACROSS YOUNG AND SOUTHERN ARCHER COUNTIES. IN OKLAHOMA VERY
STRONG THUNDERSTORMS WERE WELL NORTHEAST OF WIICHITA FALLS FROM ALEX
TO PURCELL. MOVEMENT WAS NORTHEAST AT 25 MPH.

REMEMBER A TORNADO WATCH MEANS THAT CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS TO DEVELOP IN AND NEAR THE WATCH
AREA. BE ALERT TO THREATENING WEATHER CONDITIO@NS AND LISTEN FOR LATER
STATEMENTS AND POSSIBLE WARNINGS.

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 9, 5:39 PM CDTSevere Thunderstorm WarningOUNWoods51 min
Apr 9, 5:55 PM CDTSevere Thunderstorm WarningOUNHarper50 min
Apr 9, 6:28 PM CDTSevere Thunderstorm WarningOUNAlfalfa, Woods62 min

Nearby

Tornado Warnings in Oklahoma, 1990Every tornado warning in 1990Tornadoes in 1990

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.