Alert archive / Minnesota / Severe Thunderstorm Watches in 2021
Severe Thunderstorm Watch 277
The Storm Prediction Center issued this severe thunderstorm watch at Jun 17, 2021, 7:22 PM CDT for 15 counties in Minnesota; 4 counties in Wisconsin. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 17, 2021, 7:22 PM CDT (00:22 UTC)
- Expired
- Jun 17, 2021, 11:51 PM CDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2.5 in
- Strongest gust expected
- 60 kt
Counties Blue Earth County, MN, Brown County, MN, Dakota County, MN, Faribault County, MN, Freeborn County, MN, Goodhue County, MN, Le Sueur County, MN, Martin County, MN, Nicollet County, MN, Rice County, MN, Scott County, MN, Sibley County, MN, Steele County, MN, Waseca County, MN, Watonwan County, MN, Dunn County, WI, Eau Claire County, WI, Pepin County, WI, Pierce County, WI
The radar
The Minneapolis radar (KMPX), 52 km from the middle of the area, began a volume at 00:22 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
- 5%
- One or more EF2 to EF5 tornadoes
- 2%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 60%
- One or more hailstones of 2 inches or more
- 50%
- Six or more combined severe hail and wind reports
- 80%
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 |
|---|---|---|---|---|
| Jun 17, 7:41 PM CDT | Severe Thunderstorm Warning | MPX | Nicollet, Sibley | 26 min |
| Jun 17, 7:44 PM CDT | Severe Thunderstorm Warning | MPX | Goodhue | 32 min |
| Jun 17, 7:50 PM CDT | Severe Thunderstorm Warning | MPX | Goodhue | 55 min |
| Jun 17, 8:00 PM CDT | Severe Thunderstorm Warning | MPX | Dakota, Goodhue | 45 min |
| Jun 17, 8:28 PM CDT | Severe Thunderstorm Warning | MPX | Goodhue | 34 min |
| Jun 17, 8:34 PM CDT | Severe Thunderstorm Warning | MPX | Dunn, Eau Claire, Pepin | 56 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 00:00Z, 0.4 hours before the alert went out and 54 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
- 61 J/kg
- Mixed-layer CIN
- -387 J/kg
- Mixed-layer LCL
- 1555 m above ground
- 0-6 km bulk shear
- 55 kt
- 0-1 km storm-relative helicity
- -13 m²/s²
- 0-3 km storm-relative helicity
- 56 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
The text
As transmitted.
037
WWUS20 KWNS 180018
SEL7
SPC WW 180018
MNZ000-WIZ000-180600-
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 277
NWS Storm Prediction Center Norman OK
720 PM CDT Thu Jun 17 2021
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
South-central/Southeast Minnesota
Western Wisconsin
* Effective this Thursday night and Friday morning from 720 PM
until 100 AM CDT.
* Primary threats include...
Scattered large hail likely with isolated very large hail events
to 2.5 inches in diameter possible
Isolated damaging wind gusts to 70 mph possible
SUMMARY...Scattered severe thunderstorms including some supercells
will continue generally eastward across south-central/southeast
Minnesota into western Wisconsin. Large hail should be the most
common risk, but damaging winds may also occur.
The severe thunderstorm watch area is approximately along and 40
statute miles north and south of a line from 35 miles north
northwest of Fairmont MN to 30 miles east southeast of Eau Claire
WI. For a complete depiction of the watch see the associated watch
outline update (WOUS64 KWNS WOU7).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for 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. Severe thunderstorms can and occasionally do produce
tornadoes.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 276...
AVIATION...A few severe thunderstorms with hail surface and aloft to
2.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 550. Mean storm motion vector
27030.
...GuyerSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 17, 7:02 PM CDT | Mesoscale Discussion | SPC | Blue Earth, Dakota, Dodge, Faribault, Fillmore, Freeborn and 11 more | 88 min |
| Jun 17, 9:01 PM CDT | Mesoscale Discussion | SPC | Dodge, Fillmore, Freeborn, Goodhue, Houston, Mower and 5 more | 89 min |
| Jun 17, 10:01 PM CDT | Severe Thunderstorm Watch | SPC | Dodge, Fillmore, Houston, Mower, Olmsted, Wabasha and 1 more | 6 hr |
| Jun 17, 10:52 PM CDT | Mesoscale Discussion | SPC | Fillmore, Houston, Mower, Olmsted, Wabasha, Winona | 83 min |
| Jun 18, 1:34 AM CDT | Mesoscale Discussion | SPC | Houston | 116 min |
| Jun 18, 5:03 PM CDT | Mesoscale Discussion | SPC | Becker, Beltrami, Cass, Clay, Clearwater, Crow Wing and 9 more | 87 min |
Nearby
Severe Thunderstorm Watches in Minnesota, 2021Severe Thunderstorm Watches in Wisconsin, 2021Every severe thunderstorm 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.