Alert archive / North Dakota / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 38, NWS Grand Forks, ND

July 21, 1987Grand Forks County, Steele County, North Dakota

NWS Grand Forks, ND issued this severe thunderstorm warning at Jul 21, 1987, 7:41 PM CDT for Grand Forks County, Steele County, North Dakota. It was in force for 49 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 21, 1987, 7:41 PM CDT (00:41 UTC)
Expired
Jul 21, 1987, 8:30 PM CDT
In force
49 min
Issued by
NWS Grand Forks, ND
Area
Whole counties

Counties Grand Forks County, ND, Steele 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

TimeReportWhereRemark
Jul 21, 7:45 PM CDTTornado F0Steele, ND
Jul 21, 7:55 PM CDTTornado F0Steele, 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 00:00Z, 0.7 hours before the alert went out and 256 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, Bismarck Municip, ND at 00:00Z on 1987-07-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 448 joules per kilogram.LCLLFCEL10008507005003002001001 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, Bismarck Municip, ND at 00:00Z on 1987-07-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 221 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
448 J/kg
Mixed-layer CIN
-370 J/kg
Mixed-layer LCL
701 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
221 m²/s²
0-3 km storm-relative helicity
454 m²/s²
Significant tornado parameter
0.0
Supercell composite
25.2

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.

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, 4 hours 3 minutes 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

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, 8:38 PM CDTSevere Thunderstorm WarningFGFNorman, Polk62 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 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 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.