Alert archive / Oklahoma / Severe Thunderstorm Warnings in 1987
Severe Thunderstorm Warning 261, NWS Norman, OK
NWS Norman, OK issued this severe thunderstorm warning at Jul 17, 1987, 7:13 PM CDT for Cleveland County, Grady County, McClain County, Oklahoma. It was in force for 47 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
- Jul 17, 1987, 7:13 PM CDT (00:13 UTC)
- Expired
- Jul 17, 1987, 8:00 PM CDT
- In force
- 47 min
- Issued by
- NWS Norman, OK
- Area
- Whole counties
Counties Cleveland County, OK, Grady County, OK, McClain 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 |
|---|---|---|---|
| Jul 17, 8:00 PM CDT | Thunderstorm Wind 0 | Cleveland, OK | |
| Jul 17, 8:00 PM CDT | Thunderstorm Wind 61 | Mcclain, 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 00:00Z, 0.2 hours before the alert went out and 36 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
- 2242 J/kg
- Mixed-layer CIN
- -2 J/kg
- Mixed-layer LCL
- 626 m above ground
- 0-6 km bulk shear
- 22 kt
- 0-1 km storm-relative helicity
- 322 m²/s²
- 0-3 km storm-relative helicity
- 573 m²/s²
- Significant tornado parameter
- 3.0
- Supercell composite
- 18.5
The text
The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.
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.
In the hours before
Local storm report, Jul 17, 4:12 PM CDT, 3 hours 1 minute before
STORM REPORT NATIONAL WEATHER SERVICE OKLAHOMA CITY OK 411 PM CDT FRI JUL 17 1987 TIME COUNTY REPORT 408 PM COMANCHE WINDS GREATER THAN 70 MPH IN INDIAHOMA.
The office that day
Everything else NWS Norman, OK issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 17, 7:13 PM CDT | Severe Thunderstorm Warning | OUN | Garvin | 47 min |
| Jul 17, 7:58 PM CDT | Severe Thunderstorm Warning | OUN | Garvin, Grady, McClain | 62 min |
| Jul 17, 8:32 PM CDT | Severe Thunderstorm Warning | OUN | Caddo, Canadian, Grady | 43 min |
| Jul 17, 9:13 PM CDT | Severe Thunderstorm Warning | OUN | Canadian, Grady | 47 min |
| Jul 17, 9:55 PM CDT | Severe Thunderstorm Warning | OUN | Canadian, Oklahoma | 50 min |
| Jul 17, 10:30 PM CDT | Severe Thunderstorm Warning | OUN | Kingfisher, Logan | 45 min |
| Jul 17, 10:43 PM CDT | Severe Thunderstorm Warning | OUN | Canadian, Oklahoma | 32 min |
| Jul 17, 11:11 PM CDT | Severe Thunderstorm Warning | OUN | Logan, Oklahoma | 49 min |
Nearby
Severe Thunderstorm Warnings in Oklahoma, 1987Every severe thunderstorm warning 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.