Alert archive / Minnesota / Severe Thunderstorm Warnings in 1991
Severe Thunderstorm Warning 4, NWS Grand Forks, ND
NWS Grand Forks, ND issued this severe thunderstorm warning at May 12, 1991, 9:31 PM CDT for Clay County, Norman County, Minnesota; Cass County, Traill County, North Dakota. It was in force for 44 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
- May 12, 1991, 9:31 PM CDT (02:31 UTC)
- Expired
- May 12, 1991, 10:15 PM CDT
- In force
- 44 min
- Issued by
- NWS Grand Forks, ND
- Area
- Whole counties
Counties Clay County, MN, Norman County, MN, Cass County, ND, Traill County, ND
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| May 12, 9:34 PM CDT | Thunderstorm Wind 50 | Cass, ND | |
| May 12, 9:46 PM CDT | Hail 0.75 | Clay, MN | |
| May 12, 10:05 PM CDT | Hail 0.75 | Cass, 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, 2.5 hours before the alert went out and 296 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- NaN m above ground
- 0-6 km bulk shear
- 55 kt
- 0-1 km storm-relative helicity
- -112 m²/s²
- 0-3 km storm-relative helicity
- -26 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -1.0
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, May 12, 5:47 PM CDT, 3 hours 44 minutes before
NDZ012-013-014-015-016-017-018-MNZ001-006-007-010-011-013-122345- SPECIAL WEATHER STATEMENT AND RADAR SUMMARY NATIONAL WEATHER SERVICE FARGO ND 545 PM CDT SUN MAY 12 1991 AT 535 PM CDT SCATTERED THUNDERSTORMS WERE DEVELOPING ACROSS EASTERN NORTH DAKOTA FROM NEAR DEVILS LAKE TO THE NORTH/SOUTH DAKOTA STATE LINE SOUTH OF JAMESTOWN. THE STRONGEST THUNDERSTORMS WERE IN THE DEVILS LAKE AREA AND IN THE VALLEY CITY AND LAMOURE AREAS. MOVEMENT WAS NORTH AT 35 MILES AN HOUR. THROUGH 700 PM CDT SCATTERED THUNDERSTORMS ARE EXPECTED TO CONTINUE TO DEVELOP OVER EASTERN NORTH DAKOTA. SOME OF THE STORMS WILL LIKELY BE SEVERE WITH THE POSSIBILITY OF TORNADOES...LARGE HAIL...DAMAGING WINDS AND DEADLY LIGHTNING. THE POTENTIAL EXISTS FOR EXPLOSIVE DEVELOPMENT OF THE THUNDERSTORMS...WITH RAPID CHANGES IN LOCAL WEATHER CONDITIONS A GOOD POSSIBILITY THIS EVENING. IF YOU LIVE IN OR NEAR THE TORNADO WATCH AREA STAY TUNED TO RADIO...T.V. AS WELL AS NOAA WEAHTHER RADIO FOR LATER STATEMENTS AND POSSIBLE WARNINGS. EWENS
Special weather statement, May 12, 6:33 PM CDT, 2 hours 58 minutes before
NDZ012-013-014-015-016-017-018-MNZ001-006-010-130045- SPECIAL WEATHER STATEMENT AND RADAR SUMMARY NATIONAL WEATHER SERVICE FARGO ND 633 PM CDT SUN MAY 12 1991 ...TORNADO WATCH IN EFFECT UNTIL MIDNIGHT FOR EASTERN NORTH DAKOTA... AT 625 PM CDT SCATTERED THUNDERSTORMS...A FEW STRONG...CONTINUED OVER EASTERN NORTH DAKOTA FROM NEAR DEVILS LAKE TO THE NORTH/SOUTH DAKOTA STATE LINE SOUTH OF VALLEY CITY. THE STRONGEST STORMS WERE 20 MILES SOUTH OF VALLEY CITY APPROACHING LITCHVILLE NORTH DAKOTA. OTHER STORMS WITH VERY HEAVY RAINS WERE IN THE ENDERLIN AND GWINNER AREAS. MOVEMENT WAS NORTH AT 35 MILES AN HOUR. THROUGH 800 PM CDT SCATTERED THUNDERSTORMS WILL CONTINUE OVER EASTERN NORTH DAKOTA FROM THE DEVILS LAKE AREA...THROUGH THE VALLEY CITY AREA TO NEAR LIDGERWOOD. THE STORMS WILL MOVE NORTH AT 30 MILES AN HOUR AND HAVE THE POTENTIAL TO DEVELOP RAPIDLY AND PRODUCE LARGE HAIL...DEADLY LIGHTNING...DAMAGING WINDS AND TORRENTIAL RAINS AS WELL AS THE THREAT OF TORNADOES. ALSO CONDITIONS ARE FAVORABLE FOR THE RAPID DEVELOPMENT OF SEVERE THUNDERSTORMS NORTH AND EAST OF THIS AREA OF STORMS. PLEASE STAY TUNED TO RADIO...T.V. AS WELL AS NOAA WEATHER RADIO FOR LATER STATEMENTS AND POSSIBLE WARNINGS. EWENS
Special weather statement, May 12, 7:34 PM CDT, 1 hour 57 minutes before
NDZ012-013-014-015-016-017-018-MNZ001-006-010-130135- SPECIAL WEATHER STATEMENT AND RADAR SUMMARY NATIONAL WEATHER SERVICE FARGO ND 733 PM CDT SUN MAY 12 1991 ...TORNADO WATCH IN EFFECT UNTIL MIDNIGHT FOR EASTERN NORTH DAKOTA... AT 730 PM CDT SCATTERED THUNDERSTORMS...A FEW STRONG...CONTINUED OVER EASTERN NORTH DAKOTA FROM NORTH OF DEVILS LAKE NORTH DAKOTA SOUTH TO THE NORTH/SOUTH DAKOTA STATE LINE SOUTH OF VALLEY CITY NORTH DAKOTA. OTHER THUNDERSTORMS HAD STARTED TO DEVELOP 25 TO 30 MILES SOUTH OF FARGO NORTH DAKOTA. BRIEF HEAVY RAIN AND LARGE HAIL ARE POSSIBLE WITH ANY OF THESE THUNDERSTORMS. MOVEMENT WAS NORTH AT 35 MILES AN HOUR. THROUGH 830 PM CDT SCATTERED THUNDERSTORMS WILL CONTINUE OVER EASTERN NORTH DAKOTA FROM THE DEVILS LAKE AREA...THROUGH THE VALLEY CITY AREA ON INTO WEST CENTRAL MINNESOTA. THESE THUNDERSTORMS WILL MOVE NORTH AT 30 MPH AND HAVE THE POTENTIAL TO DEVELOP RAPIDLY PRODUCING VERY HEAVY RAIN...LARGE HAIL...DAMAGING WINDS. ALSO CONDITIONS ARE FAVORABLE FOR THE RAPID DEVELOPMENT OF SEVERE THUNDERSTORMS NORTH AND EAST OF THIS AREA OF STORMS. TORNADOES ARE POSSIBLE WITH ANY OF THESE STORMS. PLEASE STAY TUNED TO RADIO...T.V. AS WELL AS NOAA WEATHER RADIO4 FOR LATER STATEMENTS AND POSSIBLE WARNINGS. ANDERSEN
Local storm report, May 12, 9:08 PM CDT, 23 minutes before
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</html>The office that day
Everything else NWS Grand Forks, ND issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 12, 7:50 PM CDT | Severe Thunderstorm Warning | FGF | Cass, Richland | 55 min |
| May 12, 8:25 PM CDT | Severe Thunderstorm Warning | FGF | Cass, Steele, Traill | 65 min |
| May 12, 8:25 PM CDT | Severe Thunderstorm Warning | FGF | Richland | 65 min |
Nearby
Severe Thunderstorm Warnings in Minnesota, 1991Severe Thunderstorm Warnings in North Dakota, 1991Every severe thunderstorm warning in 1991
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.