Alert archive / North Dakota / Severe Thunderstorm Warnings in 1987
Severe Thunderstorm Warning 31, NWS Grand Forks, ND
NWS Grand Forks, ND issued this severe thunderstorm warning at Jul 21, 1987, 3:51 PM CDT for Griggs 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, 3:51 PM CDT (20:51 UTC)
- Expired
- Jul 21, 1987, 4:45 PM CDT
- In force
- 54 min
- Issued by
- NWS Grand Forks, ND
- Area
- Whole counties
County Griggs 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, 4:20 PM CDT | Hail 0.75 | Griggs, 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, 8.9 hours before the alert went out and 201 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.
- 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
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, 13 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.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 21, 6:11 PM CDT | Severe Thunderstorm Warning | FGF | Clay, Norman | 49 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, 5:36 PM CDT | Tornado Warning | FGF | Cass, Traill | 54 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
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.