Alert archive / Minnesota / Tornado Watches in 2021
Tornado Watch 468
The Storm Prediction Center issued this tornado watch at Aug 28, 2021, 10:34 AM CDT for 20 counties in Minnesota; 14 counties in Wisconsin. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 28, 2021, 10:34 AM CDT (15:34 UTC)
- Expired
- Aug 28, 2021, 2:27 PM CDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 80 kt
All 34 counties
Aitkin County, MN, Anoka County, MN, Benton County, MN, Carlton County, MN, Carver County, MN, Chisago County, MN, Crow Wing County, MN, Dakota County, MN, Hennepin County, MN, Isanti County, MN, Kanabec County, MN, McLeod County, MN, Mille Lacs County, MN, Morrison County, MN, Pine County, MN, Ramsey County, MN, Scott County, MN, Sherburne County, MN, Washington County, MN, Wright County, MN, Ashland County, WI, Barron County, WI, Bayfield County, WI, Burnett County, WI, Chippewa County, WI, Douglas County, WI, Dunn County, WI, Iron County, WI, Polk County, WI, Price County, WI, Rusk County, WI, Saint Croix County, WI, Sawyer County, WI, Washburn County, WI
The radar
The Duluth radar (KDLH), 97 km from the middle of the area, began a volume at 15:34 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 30%
- One or more EF2 to EF5 tornadoes
- 10%
- Ten or more severe wind reports
- 70%
- One or more gusts of 65 knots or more
- 60%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 30%
- Six or more combined severe hail and wind reports
- 90%
Warnings issued inside it
6 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 28, 11:32 AM CDT | Severe Thunderstorm Warning | MPX | Morrison, Todd | 43 min |
| Aug 28, 11:45 AM CDT | Severe Thunderstorm Warning | MPX | Benton, Mille Lacs, Morrison, Sherburne | 45 min |
| Aug 28, 12:04 PM CDT | Tornado Warning | MPX | Benton, Mille Lacs | 41 min |
| Aug 28, 12:27 PM CDT | Severe Thunderstorm Warning | MPX | Isanti, Kanabec, Mille Lacs | 48 min |
| Aug 28, 12:47 PM CDT | Severe Thunderstorm Warning | DLH | Pine | 47 min |
| Aug 28, 1:29 PM CDT | Severe Thunderstorm Warning | MPX | Chisago, Isanti | 46 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Minneapolis, MN (KMPX), launched 12:00Z, 3.6 hours before the alert went out and 152 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
- 1550 J/kg
- Mixed-layer CIN
- -130 J/kg
- Mixed-layer LCL
- 676 m above ground
- 0-6 km bulk shear
- 29 kt
- 0-1 km storm-relative helicity
- 139 m²/s²
- 0-3 km storm-relative helicity
- 193 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.3
The text
As transmitted.
371
WWUS20 KWNS 281530
SEL8
SPC WW 281530
MNZ000-WIZ000-LSZ000-282100-
URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 468
NWS Storm Prediction Center Norman OK
1035 AM CDT Sat Aug 28 2021
The NWS Storm Prediction Center has issued a
* Tornado Watch for portions of
East-central Minnesota
Northwest Wisconsin
Lake Superior
* Effective this Saturday morning and afternoon from 1035 AM
until 400 PM CDT.
* Primary threats include...
A couple tornadoes possible
Scattered damaging winds and isolated significant gusts to 90
mph likely
Isolated very large hail events to 2 inches in diameter possible
SUMMARY...A small but maturing MCS should evolve into an
eastward-moving bow across east-central Minnesota into northwest
Wisconsin this afternoon. Significant damaging winds, large hail,
and brief tornadoes are the expected hazards.
The tornado watch area is approximately along and 60 statute miles
north and south of a line from 160 miles west southwest of Kennedy
WI to 40 miles southeast of Kennedy WI. For a complete depiction of
the watch see the associated watch outline update (WOUS64 KWNS
WOU8).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A Tornado Watch means conditions are favorable for
tornadoes and severe thunderstorms in and close to the watch
area. Persons in these areas should be on the lookout for
threatening weather conditions and listen for later statements
and possible warnings.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 467...
AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 2 inches. Extreme turbulence and surface wind
gusts to 80 knots. A few cumulonimbi with maximum tops to 550. Mean
storm motion vector 26045.
...GramsSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 27, 9:57 PM CDT | Mesoscale Discussion | SPC | Fillmore, Houston | 93 min |
| Aug 28, 2:17 AM CDT | Mesoscale Discussion | SPC | Big Stone, Stevens, Swift, Traverse | 2 hr |
| Aug 28, 2:32 AM CDT | Severe Thunderstorm Watch | SPC | Big Stone, Traverse | 5 hr |
| Aug 28, 5:42 AM CDT | Mesoscale Discussion | SPC | Benton, Big Stone, Chippewa, Douglas, Grant, Kandiyohi and 11 more | 2 hr |
| Aug 28, 7:08 AM CDT | Severe Thunderstorm Watch | SPC | Big Stone, Chippewa, Douglas, Grant, Kandiyohi, Lac qui Parle and 13 more | 5 hr |
| Aug 28, 9:39 AM CDT | Mesoscale Discussion | SPC | Anoka, Benton, Chisago, Douglas, Grant, Isanti and 12 more | 2 hr |
| Aug 28, 1:13 PM CDT | Mesoscale Discussion | SPC | Anoka, Chisago, Isanti, Kanabec, Pine | 2 hr |
| Aug 28, 2:43 PM CDT | Mesoscale Discussion | SPC | Murray, Nobles, Pipestone, Rock | 3 hr |
| Aug 28, 3:44 PM CDT | Tornado Watch | SPC | Cottonwood, Jackson, Lincoln, Lyon, Murray, Nobles and 2 more | 5 hr |
| Aug 28, 3:57 PM CDT | Severe Thunderstorm Watch | SPC | Cottonwood, Jackson, Murray, Nobles, Rock | 7 hr |
| Aug 28, 5:27 PM CDT | Mesoscale Discussion | SPC | Blue Earth, Brown, Carver, Cottonwood, Dakota, Dodge and 22 more | 63 min |
| Aug 28, 5:59 PM CDT | Severe Thunderstorm Watch | SPC | Blue Earth, Brown, Carver, Faribault, Freeborn, Le Sueur and 11 more | 6 hr |
| Aug 28, 6:09 PM CDT | Mesoscale Discussion | SPC | Blue Earth, Brown, Cottonwood, Nicollet, Watonwan | 66 min |
| Aug 27, 7:59 PM CDT | Mesoscale Discussion | SPC | Crawford, Grant, Iowa, Lafayette | 2 hr |
Nearby
Tornado Watches in Minnesota, 2021Tornado Watches in Wisconsin, 2021Every tornado watch in 2021
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; radar from the NEXRAD Level II archive.