Alert archive / Minnesota / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 28, NWS Grand Forks, ND

July 20, 1987Otter Tail County, Minnesota

NWS Grand Forks, ND issued this severe thunderstorm warning at Jul 20, 1987, 4:58 AM CDT for Otter Tail County, Minnesota. It was in force for 62 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 20, 1987, 4:58 AM CDT (09:58 UTC)
Expired: Jul 20, 1987, 6:00 AM CDT
In force: 62 min
Issued by: NWS Grand Forks, ND
Area: Whole counties

County Otter Tail County, MN

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
Jul 20, 5:00 AM CDT	Thunderstorm Wind 62	Otter Tail, MN
Jul 20, 5:30 AM CDT	Thunderstorm Wind 0	Otter Tail, MN
Jul 20, 5:30 AM CDT	Thunderstorm Wind 0	Otter Tail, MN

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

Minneapolis, MN (KSTC), launched 00:00Z, 10.0 hours before the alert went out and 239 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 2647 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 5 m²/s²
0-3 km storm-relative helicity: 86 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 KFAR 200959
SVRFAR
MNC111-201100-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE FARGO ND
458 AM CDT MON JUL 20 1987

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM
WARNING EFFECTIVE UNTIL 600 AM CDT FOR PEOPLE IN THE FOLLOWING
COUNTY OF

WEST CENTRAL MINNESOTA...OTTER TAIL

INCLUDING THE CITIES OF FERGUS FALLS..BATTLE LAKE AND PELICAN
RAPIDS.

AT 455 AM CDT RADAR INDICATED A LINE OF SEVERE THUNDERSTORMS
OVER WESTERN OTTERTAIL COUNTY MOVING NORTHEAST AT 30 MILES
AN HOUR.

REMEMBER...SEVERE THUNDERSTORMS CAN PRODUCE DAMAGING WINDS IN EXCESS
OF 58 MPH AND/OR HAIL 3/4 INCH OR LARGER...DEADLY LIGHTNING...
AND HEAVY RAINS THAT CAN QUICKLY FLOOD A LOW LYING AREA.

THIS IS A DANGEROUS STORM.  TAKE COVER IMMEDIATELY.

EWENS

The office that day

Everything else NWS Grand Forks, ND issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 20, 3:15 AM CDT	Severe Thunderstorm Warning	FGF	Clay	60 min
Jul 20, 3:47 AM CDT	Severe Thunderstorm Warning	FGF	Becker, Mahnomen	58 min
Jul 20, 4:20 AM CDT	Severe Thunderstorm Warning	FGF	Wilkin	60 min
Jul 20, 5:47 AM CDT	Severe Thunderstorm Warning	FGF	Hubbard, Wadena	58 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 1987 Every 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.