Alert archive / Oklahoma / Tornado Warnings in 1987
Tornado Warning 8, NWS Norman, OK
NWS Norman, OK issued this tornado warning at May 21, 1987, 5:35 PM CDT for Logan County, Oklahoma. It was in force for 40 min. 2 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 21, 1987, 5:35 PM CDT (22:35 UTC)
- Expired
- May 21, 1987, 6:15 PM CDT
- In force
- 40 min
- Issued by
- NWS Norman, OK
- Area
- Whole counties
County Logan 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
| Time | Report | Where | Remark |
|---|---|---|---|
| May 21, 5:44 PM CDT | Hail 1 | Logan, OK | |
| May 21, 6:24 PM CDT | Hail 1.75 | Logan, 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
Ok Cty/Will Rgrs, OK (KOKC), launched 12:00Z, 10.6 hours before the alert went out and 59 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.
- Mixed-layer CAPE
- 2809 J/kg
- Mixed-layer CIN
- -100 J/kg
- Mixed-layer LCL
- 976 m above ground
- 0-6 km bulk shear
- 22 kt
- 0-1 km storm-relative helicity
- 81 m²/s²
- 0-3 km storm-relative helicity
- 98 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.0
The text
As transmitted, in the capitals the NWS used until 2016.
000
TTAA00 KOKC 212235
TOROKC
OKC083-212315-
BULLETIN - EBS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE OKLAHOMA CITY OK
535 PM CDT THU MAY 21 1987
THE NATIONAL WEATHER SERVICE HAS ISSUED A TORNADO WARNING
EFFECTIVE UNTIL 615 PM CDT FOR PEOPLE IN THE FOLLOWING COUNTY...
IN CENTRAL OKLAHOMA
...SOUTHERN LOGAN
AT 535 PM CDT RADAR INDICATED A POSSIBLE TORNADO 2 MILES SOUTH OF
GUTHRIE MOVING TOWARD THE EAST AT 5 MILES PER HOUR. THIS STORM IS
CAPABLE OF PRODUCING HAIL LARGER THAN GOLFBALLS AND WINDS IN EXCESS
OF 60 MILES PER HOUR.
IF YOU ARE IN THE PATH OF A TORNADO...THE SAFEST PLACE IS A
BASEMENT. GET UNDER A WORKBENCH OR PIECE OF STURDY FURNITURE.
IF NO BASEMENT IS AVAILABLE.<..SEEK SHELTER IN AN INTERIOR ROOM
SUCH AS A CLOSET ON THE LOWEST FLOOR. USE BLANKETS...PILLOWS...
OR CUSHIONS TO COVER YOUR BODY. AVOID WINDOWS.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 21, 12:03 PM CDT, 5 hours 32 minutes before
OKLAHOMA THUNDERSTORM OUTLOOK NATIONAL WEATHER SERVICE OKLAHOMA CITY OK 1200 PM CDT THU MAY 21 1987 A MODERATE RISK OF SEVERE THUNDERSTORMS EXISTS OVER PORTIONS OF NORTHERN AND EASTERN OKLAHOMA THIS AFTERNOON AND TONIGHT. THE MODERATE RISK AREA COVERS THAT PORTION OF OKLAHOMA NORTH AND EAST OF A PONCA CITY...OKLAHOMA CITY...FORT SMITH AR LINE. THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF SOUTHERN OKLAHOMA. THE SLIGHT RISK AREA LIES EAST OF AN ALTUS...OKLAHOMA CITY LINE AND WEST OF A DURANT...FORT SMITH AR LINE...AND BORDERS THE MODERATE RISK AREA TO THE NORTH. AT MIDDAY...A COLD FRONT HAS PUSHED ACROSS NORTHWEST PORTIONS OF OKLAHOMA AND CURRENTLY LIES ALONG A PONCA CITY-HOLLIS LINE. THIS FRONT CONTINUES TO PUSH SLOWLY SOUTHEASTWARD. A DRY LINE EXTENDS FROM THE FRONT NEAR OKLAHOMA CITY SOUTHWARD INTO NORTH TEXAS TO THE WEST OF ABILENE. THE LOCATION WHERE THE FRONT AND DRYLINE INTERSECT IS CALLED A 'TRIPLE POINT' BY METEOROLOGISTS...AND IS OFTEN A FOCUS FOR SEVERE WEATHER DEVELOPMENT. LOW LEVEL MOISTURE IS SURGING NORTHWARD AHEAD OF THE FRONT AND DRYLINE...ACROSS THE SOUTHEASTERN TWO-THIRDS OF THE STATE...WHERE THE AIRMASS IS EXTREMELY UNSTABLE. THE POTENTIAL EXISTS FOR A SIGNIFICANT OUTBREAK OF SEVERE WEATHER OVER PORTIONS OF THE STATE THIS AFTERNOON AND TONIGHT. THUNDERSTORM DEVELOPMENT IS EXPECTED TO BEGIN BY MID-AFTERNOON...MOST LIKELY ALONG THE FRONT AND/OR DRYLINE. THE TRIPLE POINT IS EXPECTED TO MOVE SLOWLY NORTHEASTWARD ALONG THE FRONT...MOVING INTO NORTH CENTRAL OR NORTHEAST OKLAHOMA BY LATE AFTERNOON. THE BEST CHANCE FOR SEVERE WEATHER EXISTS NEAR THE TRIPLE POINT...BUT SEVERE ACTIVITY CANNOT BE RULED OUT ANYWHERE IN OKLAHOMA NEA?R THE FRONT OR DRYLINE. CIVIL DEFENSE AND STORM SPOTTER GROUPS IN THE OUTLOOK AREA SHOULD REMAIN ALERT AND BE READY FOR ACTIVATION LATER THIS AFTERNOON. LATER INFORMATION WILL BE INCLUDED IN THE UPDATED OUTLOOK TO BE ISSUED AROUND 3 PM.
Special weather statement, May 21, 3:18 PM CDT, 2 hours 17 minutes before
OKLAHOMA THUNDERSTORM OUTLOOK NATIONAL WEATHER SERVICE OKLAHOMA CITY OK 315 PM CDT THU MAY 21 1987 A MODERATE RISK OF SEVERE THUNDERSTORMS EXISTS OVER PORTIONS OF NORTHERN AND EASTERN OKLAHOMA THIS AFTERNOON AND TONIGHT. THE MODERATE RISK AREA COVERS THAT PORTION OF OKLAHOMA NORTH AND EAST OF A PONCA CITY...OKLAHOMA CITY...FORT SMITH AR LINE. THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF SOUTHERN OKLAHOMA. THE SLIGHT RISK AREA LIES EAST OF AN ALTUS...OKLAHOMA CITY LINE AND WEST OF A DURANT...FORT SMITH AR LINE...AND BORDERS THE MODERATE RISK AREA TO THE NORTH. AT MIDAFTERNOON...A STATIONARY FRONT EXTENDS ALONG A LINE FROM PONCA CITY TO CHILDRESS TX. A DRY LINE EXTENDS FROM THE FRONT NEAR OKLAHOMA CITY SOUTHWARD INTO NORTH TEXAS TO THE WEST OF ABILENE. THE LOCATION WHERE THE FRONT AND DRYLINE INTERSECT IS CALLED A 'TRIPLE POINT' BY METEOROLOGISTS...AND IS OFTEN A FOCUS FOR SEVERE WEATHER DEVELOPMENT. LOW LEVEL MOISTURE COVERS THE SOUTHEASTERN TWO-THIRDS OF THE STATE AHEAD OF THE FRONT AND DRYLINE. UPPER AIR INFORMATION RECEIVED AROUND 2 PM FROM SOUTH CENTRAL OKLAHOMA INDICATES THE ATMOSPHERE IS NOT QUITE AS EXPLOSIVELY UNSTABLE AS IT WAS EARLIER TODAY. HOWEVER...THUNDERSTORM ACTIVITY IS STARTING TO FIRE UP ALONG THE COLD FRONT TO OUR NORTHEAST IN MISSOURI...AND TO OUR SOUTH IN TEXAS ALONG THE DRYLINE. SUFFICIENT INSTABILITY STILL EXISTS OVER OKLAHOMA...AND THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE COLD FRONT AND/OR DRYLINE BY 4 PM. THE POTENTIAL REMAINS FOR A SIGNIFICANT OUTBREAK OF SEVERE WEATHER OVER PORTIONS OF THE STATE THIS AFTERNOON AND TONIGHT. THE BEST CHANCE FOR SEVERE WEATHER EXISTS NEAR THE TRIPLE POINT...BUT SEVERE ACTuIVITY CANNOT BE RULED OUT ANYWHERE IN OKLAHOMA NEAR THE FRONT OR DRYLINE. CIVIL DEFENSE AND STORM SPOTTER GROUPS IN THE OUTLOOK AREA SHOULD EXPECT TO BE ACTIVATED BY LATE AFTERNOON.
Special weather statement, May 21, 5:25 PM CDT, 10 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE WICHITA FALLS TX 525 PM CDT THU MAY 21 1987 AT 520 PM THE WICHITA FALLS NATIONAL WEATHER RADAR SHOWED A BAND OF THUNDERSTORMS A FEW PRODUCING VERY HEAVY RAIN DEVELOPING FROM VERNON TO JUST NORTH OF ABILENE. THE HEAVIEST RAINS WERE FALLING JUST WEST OF LAKE KEMP AND TO THE SOUTHWEST OF SEYMOUR. THESE STORMS WERE MOVING TO THE NORTHEAST AT 15 TO 20 MPH. AT PRESENT NO SEVERE WEATHER WAS INDICATED IN ASSOCIATION WITH THESE STORMS. HOWEVER THE POTENTIAL FOR SEVERE WEATHER DOES EXIST ACROSS THE AREA THIS AFTERNOON. THE STORMS COULD POSSIBLY INTENSITY. RESIDENTS ARE ADVISED TO STAY TUNED TO NOAA WEATHER RADIO OR COMMERCIAL RADIO AND T.V. FOR LATER STATEMENTS AND POSSIBLE WARNINGS.
Special weather statement, May 21, 5:26 PM CDT, 9 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE WICHITA FALLS TX 525 PM CDT THU MAY 21 1987 AT 520 PM THE WICHITA FALLS NATIONAL WEATHER RADAR SHOWED A BAND OF THUNDERSTORMS A FEW PRODUCING VERY HEAVY RAIN DEVELOPING FROM VERNON TO JUST NORTH OF ABILENE. THE HEAVIEST RAINS WERE FALLING JUST WEST OF LAKE KEMP AND TO THE SOUTHWEST OF SEYMOUR. THESE STORMS WERE MOVING TO THE NORTHEAST AT 15 TO 20 MPH. AT PRESENT NO SEVERE WEATHER WAS INDICATED IN ASSOCIATION WITH THESE STORMS. HOWEVER THE POTENTIAL FOR SEVERE WEATHER DOES EXIST ACROSS THE AREA THIS AFTERNOON. THE STORMS COULD POSSIBLY INTENSIFY. RESIDENTS ARE ADVISED TO STAY TUNED TO NOAA WEATHER RADIO OR COMMERCIAL RADIO AND T.V. FOR LATER STATEMENTS AND POSSIBLE WARNINGS.
The office that day
Everything else NWS Norman, OK issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 20, 7:19 PM CDT | Severe Thunderstorm Warning | OUN | Washita | 26 min |
| May 20, 8:48 PM CDT | Severe Thunderstorm Warning | OUN | Canadian | 27 min |
| May 21, 4:49 PM CDT | Severe Thunderstorm Warning | OUN | Logan, Oklahoma | 56 min |
| May 21, 4:59 PM CDT | Tornado Warning | OUN | Logan | 31 min |
| May 21, 5:23 PM CDT | Severe Thunderstorm Warning | OUN | Blaine, Canadian, Kingfisher | 52 min |
| May 21, 5:29 PM CDT | Severe Thunderstorm Warning | OUN | Canadian, Oklahoma | 46 min |
| May 21, 6:03 PM CDT | Severe Thunderstorm Warning | OUN | Caddo, Canadian | 57 min |
| May 21, 6:13 PM CDT | Severe Thunderstorm Warning | OUN | Lincoln, Logan, Oklahoma | 47 min |
Nearby
Tornado Warnings in Oklahoma, 1987Every tornado warning in 1987Tornadoes in 1987
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.