Alert archive / Minnesota / Severe Thunderstorm Warnings in 1987
Severe Thunderstorm Warning 121, NWS Twin Cities, MN
NWS Twin Cities, MN issued this severe thunderstorm warning at Aug 21, 1987, 3:55 PM CDT for Yellow Medicine County, Minnesota. It was in force for 50 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
- Aug 21, 1987, 3:55 PM CDT (20:55 UTC)
- Expired
- Aug 21, 1987, 4:45 PM CDT
- In force
- 50 min
- Issued by
- NWS Twin Cities, MN
- Area
- Whole counties
County Yellow Medicine County, MN
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 |
|---|---|---|---|
| Aug 21, 3:58 PM CDT | Hail 0.75 | Yellow Medicine, MN |
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
Minneapolis, MN (KSTC), launched 12:00Z, 8.9 hours before the alert went out and 180 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
- 1133 J/kg
- Mixed-layer CIN
- -142 J/kg
- Mixed-layer LCL
- 643 m above ground
- 0-6 km bulk shear
- 44 kt
- 0-1 km storm-relative helicity
- 138 m²/s²
- 0-3 km storm-relative helicity
- 96 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.5
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, Aug 21, 2:54 PM CDT, 1 hour 1 minute before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY NATIONAL WEATHER SERVICE MINNEAPOLIS/ST PAUL MN 250 PM CDT FRI AUG 21 1987 AT 233 PM CDT...INTENSE THUNDERSTORMS WERE LOCATED OVER CENTRAL MINNESOTA IN THE LONG PRAIRRIE AND FT RIPLEY AREAS AND OVER EAST CENTRAL MINNESOTA SOUTH AND SOUTHEAST OF AITKIN. HAIL...INTENSE RAINFALL AND FREQUENT DANGEROUS LIGHTNING CAN BE EXPECTED WITH THE STORMS AS THEY MOVE EAST AT 30 MILES AN HOUR. THE STORMS WERE PART OF A BAND OF THUNDERSTORMS THAT EXTENDED FROM ALEXANDRIA TO JUST WEST OF DULUTH. THE STORMS WERE MOVING EAST AT 30 MILES AN HOUR. LIGHT RAINSHOWERS WERE SCATTERED OVER SOUTH CENTRAL INTO EAST CENTRAL MINNESOTA FROM EAST OF REDWOOD FALLS TO Q30 MILES WEST OF MINNEAPOLIS. LIGHT RAINSHOWERS WERE ALSO LOCATED OVER WESTERN WISCONSIN FROM > SOUTH OF HAYWARD TO EAU CLAIRE TO NEW RICHMOND. ALL OF THE SHOWERS WERE MOVING EAST AT 35 MILES AN HOUR. STANDFIELD
The office that day
Everything else NWS Twin Cities, MN issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 21, 2:12 AM CDT | Severe Thunderstorm Warning | MPX | Waseca | 18 min |
| Aug 21, 2:23 AM CDT | Severe Thunderstorm Warning | MPX | Freeborn, Steele | 22 min |
| Aug 21, 2:39 AM CDT | Severe Thunderstorm Warning | MPX | Dodge, Mower | 36 min |
| Aug 21, 1:55 PM CDT | Severe Thunderstorm Warning | MPX | Todd | 65 min |
| Aug 21, 2:25 PM CDT | Severe Thunderstorm Warning | MPX | Morrison | 65 min |
| Aug 21, 3:25 PM CDT | Severe Thunderstorm Warning | MPX | Chippewa, Lac qui Parle | 60 min |
Nearby
Severe Thunderstorm Warnings in Minnesota, 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.