Alert archive / Wisconsin / Severe Thunderstorm Watches in 2021
Severe Thunderstorm Watch 394
The Storm Prediction Center issued this severe thunderstorm watch at Jul 26, 2021, 7:25 PM CDT for 8 counties in Wisconsin. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 26, 2021, 7:25 PM CDT (00:25 UTC)
- Expired
- Jul 26, 2021, 10:39 PM CDT
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 3 in
- Strongest gust expected
- 70 kt
Counties Ashland County, WI, Bayfield County, WI, Burnett County, WI, Douglas County, WI, Iron County, WI, Price County, WI, Sawyer County, WI, Washburn County, WI
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 20%
- One or more EF2 to EF5 tornadoes
- 5%
- Ten or more severe wind reports
- 40%
- One or more gusts of 65 knots or more
- 40%
- Ten or more severe hail reports
- 40%
- One or more hailstones of 2 inches or more
- 40%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
1 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 26, 7:30 PM CDT | Severe Thunderstorm Warning | DLH | Douglas | 60 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 262 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
- 1670 J/kg
- Mixed-layer CIN
- -151 J/kg
- Mixed-layer LCL
- 1398 m above ground
- 0-6 km bulk shear
- 46 kt
- 0-1 km storm-relative helicity
- 146 m²/s²
- 0-3 km storm-relative helicity
- 187 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 5.9
The text
As transmitted.
053
WWUS20 KWNS 270024
SEL4
SPC WW 270024
WIZ000-LSZ000-270500-
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 394
NWS Storm Prediction Center Norman OK
725 PM CDT Mon Jul 26 2021
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Northwest Wisconsin
Lake Superior
* Effective this Monday night from 725 PM until Midnight CDT.
* Primary threats include...
Scattered damaging winds and isolated significant gusts to 80
mph possible
Scattered large hail and isolated very large hail events to 3
inches in diameter possible
A tornado or two possible
SUMMARY...Long-lived supercell cluster should continue
east-southeast from northeast Minnesota into northwest Wisconsin
through late evening.
The severe thunderstorm watch area is approximately along and 65
statute miles north and south of a line from 5 miles south of
Ironwood MI to 15 miles south southwest of Duluth MN. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU4).
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 393...
AVIATION...A few severe thunderstorms with hail surface and aloft to
3 inches. Extreme turbulence and surface wind gusts to 70 knots. A
few cumulonimbi with maximum tops to 550. Mean storm motion vector
31030.
...GramsSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 26, 7:12 PM CDT | Mesoscale Discussion | SPC | Ashland, Bayfield, Burnett, Douglas, Sawyer, Washburn | 93 min |
| Jul 26, 8:41 PM CDT | Mesoscale Discussion | SPC | Ashland, Barron, Bayfield, Burnett, Douglas, Iron and 6 more | 94 min |
| Jul 26, 11:50 PM CDT | Mesoscale Discussion | SPC | Bayfield, Brown, Calumet, Door, Douglas, Fond du Lac and 20 more | 55 min |
| Jul 27, 4:00 AM CDT | Mesoscale Discussion | SPC | Barron, Dunn, Pepin, Pierce, Polk, Saint Croix | 3 hr |
| Jul 27, 7:48 AM CDT | Mesoscale Discussion | SPC | Adams, Crawford, Iowa, Jackson, Juneau, La Crosse and 4 more | 117 min |
Nearby
Severe 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.