Alert archive / Oklahoma / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 249, NWS Norman, OK

July 12, 1987Alfalfa County, Garfield County, Grant County, Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at Jul 12, 1987, 4:50 PM CDT for Alfalfa County, Garfield County, Grant County, Oklahoma. It was in force for 55 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
Jul 12, 1987, 4:50 PM CDT (21:50 UTC)
Expired
Jul 12, 1987, 5:45 PM CDT
In force
55 min
Issued by
NWS Norman, OK
Area
Whole counties

Counties Alfalfa County, OK, Garfield County, OK, Grant 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
Jul 12, 5:00 PM CDTHail 0.75Alfalfa, OK
Jul 12, 5:00 PM CDTHail 0.75Grant, OK
Jul 12, 5:20 PM CDTThunderstorm Wind 61Grant, 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, 9.8 hours before the alert went out and 141 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, Ok Cty/Will Rgrs, OK at 12:00Z on 1987-07-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2074 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Ok Cty/Will Rgrs, OK at 12:00Z on 1987-07-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 191 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
2074 J/kg
Mixed-layer CIN
-110 J/kg
Mixed-layer LCL
747 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
191 m²/s²
0-3 km storm-relative helicity
222 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 12, 4:10 PM CDTSevere Thunderstorm WarningOUNAlfalfa, Major50 min
Jul 12, 4:10 PM CDTSevere Thunderstorm WarningOUNGrant50 min
Jul 12, 4:41 PM CDTSevere Thunderstorm WarningOUNMajor19 min
Jul 12, 4:50 PM CDTSevere Thunderstorm WarningOUNBlaine, Custer, Dewey, Major55 min
Jul 12, 5:43 PM CDTSevere Thunderstorm WarningOUNBlaine, Custer, Dewey, Major62 min
Jul 12, 6:01 PM CDTSevere Thunderstorm WarningOUNBeckham, Roger Mills59 min
Jul 12, 6:40 PM CDTSevere Thunderstorm WarningOUNBlaine, Custer65 min
Jul 12, 6:53 PM CDTSevere Thunderstorm WarningOUNBeckham67 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.