Alert archive / Minnesota / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 40, NWS Grand Forks, ND

July 21, 1987Norman County, Polk County, Minnesota; Traill County, North Dakota

NWS Grand Forks, ND issued this severe thunderstorm warning at Jul 21, 1987, 8:38 PM CDT for Norman County, Polk County, Minnesota; Traill County, North Dakota. It was in force for 62 min.

The area

The counties it named.

The facts

Issued
Jul 21, 1987, 8:38 PM CDT (01:38 UTC)
Expired
Jul 21, 1987, 9:40 PM CDT
In force
62 min
Issued by
NWS Grand Forks, ND
Area
Whole counties

Counties Norman County, MN, Polk County, MN, Traill County, ND

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

The nearest sounding before it

International Fa, MN (KINL), launched 00:00Z, 1.6 hours before the alert went out and 277 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, International Fa, MN at 00:00Z on 1987-07-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, International Fa, MN at 00:00Z on 1987-07-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 54 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1603 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
54 m²/s²
0-3 km storm-relative helicity
161 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 220138
SVRFAR
NDC097-MNC107-119-220240-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE FARGO ND
838 PM CDT TUE JUL 21 1987

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM 
WARNING EFFECTIVE UNTIL 940 PM CDT FOR PEOPLE IN THE FOLLOWING 
COUNTIES OF

EAST CENTRAL NORTH DAKOTA...EASTERN TRAILL
NORTHWEST MINNESOTA...NORTHERN NORMAN AND SOUTHERN POLK

INCLUDING SHELLY AND CROOKSTON.
AT 815 PM CDT 66 MPH WINDS WERE REPORTED IN MAYVILLE NORTH DAKOTA.

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.

REMEMBER...SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE
A TORNADO WITH LITTLE OR NO ADVANCE WARNING SO BE ON THE LOOKOUT.

IF THREATENING WEATHER APPROACHES...YOU SHOULD GO TO A PLACE OF
SAFETY IMMEDIATELY.  REPORT ALL SEVERE WEATHER TO YOUR LOCAL LAW
ENFORCEMENT AGENCY AFTER THE STORM PASSES.

VOELKER

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

Special weather statement, Jul 21, 3:38 PM CDT, 5 hours before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE FARGO ND
335 PM CDT TUE JUL 21 1987

...A SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 9 PM CDT THIS
   TUESDAY EVENING FOR A LARGE PART OF NORTH DAKOTA AND A PART
   OF NORTHWEST MINNESOTA...

AT 325 PM CDT...A PAIR OF INTENSE THUNDERSTORMS WERE LOCATED
30 MILES AND 50 MILES NORTHWEST OF JAMESTOWN NORTH DAKOTA OR
NEAR THE TOWNS OF NEW ROCKFORD AND CARRINGTON.  THESE THUNDERSTORMS
WERE MOVING TO THE EAST AT 40 MILES AN HOUR AND WILL MOVE INTO GRIGGS
AND SOUTHERN NELSON COUNTIES BY 425 PM CDT.  PERSONS LIVING IN THESE
AREAS...ESPECIALLY THE TOWNS OF COOPERSTOWN...HANNAFORD...AND DAZEY
SHOULD BE ALERT FOR RAPIDLY CHANGING WEATHER CONDITIONS AND SHOULD BE
PREPARED TO SEEK SHELTER IF NECESSARY.

ALSO AT 325 PM CDT...SCATTERED SHOWERS AND THUNDERSTORMS...SOME WITH
HEAVY RAIN...WERE LOCATED OVER NORTHEAST AND CENTRAL NORTH DAKOTA.
THESE SHOWERS AND THUNDERSTORMS W(ERE ALSO MOVING TO THE EAST AT
40 MILES AN HOUR.
MB
Local storm report, Jul 21, 8:18 PM CDT, 20 minutes before
STORM REPORTS
NATIONAL WEATHER SERVICE FARGO ND
800PM CDT WED JUL 21 1987

TIME      EVENT
502 PM CDT   SPOTTER IN HOPE NORTH DAKOTA IN STEELE COUNTY REPORTED HEAVY
             RAIN AND HAIL UP TO 2 INCHES.

505 PM CDT   SPOTTER REPORTED FUNNEL CLOUD 10 MILES WEST OF HOPE NORTH
             DAKOTA IN STEELE COUNTY.

505 PM CDT   SPOTTER REPORTED MARBLE-GOLFBALL SIZED HAIL 4 AND 9 MILES
             WEST OF COOPERSTOWN NORTH DAKOTA IN GRIGGS COUNTY.

530 PM CDT   GOLFBALL TO BASEBALL SIZE HAIL AT CLIFFORD NORTH DAKOTA
             IN TRAILL COUNTY BY LAW ENFORCEMENT.

555 PM CDT   STATE RADIO RELAYS LAW ENFORCEMENT REPORT OF TORNADO
             TOUCHDOWN AT BLANCHARD NORTH DAKOTA IN TRAIL COUNTY.
.
620 PM CDT   1 MILES WEST, 11/2 MILES NORTH OF PILLSBURY NORTH DAKOTA
             SPOTTER REPORTED 1 INCH OF RAIN IN 15 MINUTES AND GOLFBALL
             SIZE HAIL...BARNES COUNTY
VOELKER
Local storm report, Jul 21, 8:31 PM CDT, 7 minutes before
STORM REPORTS...CORRECTED FOR DAY
NATIONAL WEATHER SERVICE FARGO ND
800PM CDT TUE JUL 21 1987

TIME      EVENT
502 PM CDT   SPOTTER IN HOPE NORTH DAKOTA IN STEELE COUNTY REPORTED HEAVY
             RAIN AND HAIL UP TO 2 INCHES.

505 PM CDT   SPOTTER REPORTED FUNNEL CLOUD 10 MILES WEST OF HOPE NORTH
             DAKOTA IN STEELE COUNTY.

505 PM CDT   SPOTTER REPORTED MARBLE-GOLFBALL SIZED HAIL 4 AND 9 MILES
             WEST OF COOPERSTOWN NORTH DAKOTA IN GRIGGS COUNTY.

530 PM CDT   GOLFBALL TO BASEBALL SIZE HAIL AT CLIFFORD NORTH DAKOTA
             IN TRAILL COUNTY BY LAW ENFORCEMENT.

555 PM CDT   STATE RADIO RELAYS LAW ENFORCEMENT REPORT OF TORNADO
             TOUCHDOWN AT BLANCHARD NORTH DAKOTA IN TRAIL COUNTY.
.
620 PM CDT   1 MILES WEST, 11/2 MILES NORTH OF PILLSBURY NORTH DAKOTA
             SPOTTER REPORTED 1 INCH OF RAIN IN 15 MINUTES AND GOLFBALL
             SIZE HAIL...BARNES COUNTY
VOELKER

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 21, 7:02 PM CDTSevere Thunderstorm WarningFGFClay, Norman58 min
Jul 21, 7:58 PM CDTTornado WarningFGFBecker, Clay, Mahnomen, Otter Tail62 min
Jul 21, 8:45 PM CDTSevere Thunderstorm WarningFGFBeltrami, Clearwater60 min
Jul 21, 9:00 PM CDTSevere Thunderstorm WarningFGFBecker, Hubbard, Wadena60 min
Jul 21, 11:26 PM CDTSevere Thunderstorm WarningFGFNorman49 min
Jul 22, 12:15 AM CDTSevere Thunderstorm WarningFGFMahnomen, Norman50 min
Jul 22, 1:21 AM CDTSevere Thunderstorm WarningFGFBecker, Mahnomen, Norman54 min
Jul 22, 1:30 AM CDTSevere Thunderstorm WarningFGFClearwater75 min
Jul 22, 1:53 AM CDTSevere Thunderstorm WarningFGFNorman52 min
Jul 22, 1:53 AM CDTSevere Thunderstorm WarningFGFClay52 min
Jul 21, 7:14 PM CDTTornado WarningFGFNelson61 min
Jul 21, 7:41 PM CDTSevere Thunderstorm WarningFGFGrand Forks, Steele49 min
Jul 21, 7:41 PM CDTSevere Thunderstorm WarningFGFGriggs49 min
Jul 21, 8:49 PM CDTSevere Thunderstorm WarningFGFNelson56 min
Jul 21, 9:50 PM CDTSevere Thunderstorm WarningFGFGriggs, Nelson, Steele55 min
Jul 21, 9:50 PM CDTSevere Thunderstorm WarningFGFGrand Forks, Traill55 min
Jul 21, 10:44 PM CDTSevere Thunderstorm WarningFGFGriggs, Steele, Traill61 min
Jul 21, 11:53 PM CDTSevere Thunderstorm WarningFGFSteele, Traill52 min
Jul 21, 11:53 PM CDTSevere Thunderstorm WarningFGFGriggs52 min
Jul 22, 12:47 AM CDTSevere Thunderstorm WarningFGFSteele, Traill58 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 1987Severe Thunderstorm Warnings in North Dakota, 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; the sounding from the Mesonet's radiosonde archive.