Alert archive / North Dakota / Tornado Warnings in 1987

Tornado Warning 9, NWS Grand Forks, ND

July 21, 1987Cass County, Traill County, North Dakota

NWS Grand Forks, ND issued this tornado warning at Jul 21, 1987, 5:36 PM CDT for Cass County, Traill County, North Dakota. It was in force for 54 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: Jul 21, 1987, 5:36 PM CDT (22:36 UTC)
Expired: Jul 21, 1987, 6:30 PM CDT
In force: 54 min
Issued by: NWS Grand Forks, ND
Area: Whole counties

Counties Cass County, ND, Traill County, ND

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 21, 5:45 PM CDT	Tornado F0	Traill, ND

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

Bismarck Municip, ND (KBIS), launched 12:00Z, 10.6 hours before the alert went out and 269 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: 707 J/kg
Mixed-layer CIN: -206 J/kg
Mixed-layer LCL: 955 m above ground
0-6 km bulk shear: 50 kt
0-1 km storm-relative helicity: 90 m²/s²
0-3 km storm-relative helicity: 135 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.2

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
TTAA00 KFAR 212236
TORFAR
NDC017-097-212330-

BULLETIN - IMMEDIATE BROADCAST REQUESTED/EBS ACTIVATION REQUESTED 
TORNADO WARNING
NATIONAL WEATHER SERVICE FARGO ND
536 PM CDT TUE JUL 21 1987

THE NATIONAL WEATHER SERVICE HAS ISSUED A TORNADO WARNING 
EFFECTIVE UNTIL 630 PM CDT FOR PEOPLE IN THE FOLLOWING COUNTIES OF

EAST CENTRAL NORTH DAKOTA...NORTHERN CASS AND TRAILL

INCLUDING THE TOWNS OF BLANCHARD...PAGE AND HUNTER
AT 525 PM CDT...RADAR INDICATE A SEVERE THUNDERSTORM 35 MILES NORTH
OF FARGO NORTH DAKOTA OR 10 MILES WEST OF BLANCHARD MOVING TOWARD
THE EAST AT 40 MILES AN HOUR.
AT 520 PM CDT A SPOTTER REPORTED A TORNADO WEST OF HUNTER.

IF YOU ARE IN THE PATH OF THIS TORNADO...GO TO A BASEMENT SHELTER
IF AVAILABLE...OTHERWISE TO A CENTRAL INTERIOR ROOM ON THE LOWEST
FLOOR.  ABANDON CARS AND MOBILE HOMES FOR A REINFORCED BUILDING.
IF CAUGHT OUTDOORS...GET INTO A DITCH...GULLY...RAVINE...OR EVEN
A LOW LYING SPOT ON THE GROUND.  PROTECT YOUR HEAD.

THIS STORM IS ACCOMPANIED BY INTENSE LIGHTNING...LARGE HAIL...AND
DANGEROUS STRAIGHT LINE WINDS.

THIS IS A DANGEROUS STORM.  TAKE COVER IMMEDIATELY.

VOELKER

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 21, 3:51 PM CDT	Severe Thunderstorm Warning	FGF	Griggs	54 min
Jul 21, 4:37 PM CDT	Severe Thunderstorm Warning	FGF	Steele	53 min
Jul 21, 4:51 PM CDT	Tornado Warning	FGF	Barnes, Cass, Steele	39 min
Jul 21, 4:51 PM CDT	Tornado Warning	FGF	Traill	39 min
Jul 21, 5:01 PM CDT	Severe Thunderstorm Warning	FGF	Barnes, Griggs	59 min
Jul 21, 5:49 PM CDT	Severe Thunderstorm Warning	FGF	Barnes, Steele	56 min
Jul 21, 6:29 PM CDT	Severe Thunderstorm Warning	FGF	Cass	61 min

Nearby

Tornado Warnings in North Dakota, 1987 Every tornado warning in 1987 Tornadoes 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.