Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2026
Severe Thunderstorm Warning 38, NWS Green Bay, WI
NWS Green Bay, WI issued this severe thunderstorm warning at Apr 17, 2026, 6:58 PM CDT for Oneida County, Vilas County, Wisconsin. It was in force for 32 min. No storm report in the archive falls inside the area while it was in force.
The area
The counties it named.
The facts
- Issued
- Apr 17, 2026, 6:58 PM CDT (23:58 UTC)
- Expired
- Apr 17, 2026, 7:30 PM CDT
- In force
- 32 min
- Issued by
- NWS Green Bay, WI
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 60.0 mph
Counties Oneida County, WI, Vilas County, WI
The radar
The Marquette radar (KMQT), 168 km from the middle of the area, began a volume at 00:01 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.
The watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Apr 17, 9:23 AM CDT | Severe Thunderstorm Watch | SPC | 11 hr |
The nearest sounding before it
Minneapolis, MN (KMPX), launched 12:00Z, 12.0 hours before the alert went out and 339 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
- 1 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 2301 m above ground
- 0-6 km bulk shear
- 39 kt
- 0-1 km storm-relative helicity
- 188 m²/s²
- 0-3 km storm-relative helicity
- 229 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
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.
NWS Green Bay, WI wrote its last area forecast discussion before this severe thunderstorm warning went out at Apr 17, 6:43 PM CDT, 15 minutes earlier. Its key messages:
- -Severe storms with a risk of tornadoes (possibly strong), large hail and damaging winds are increasingly likely from 3 pm to 8 pm today, with the highest risk across central Wisconsin. -Thunderstorms this afternoon and evening will produce locally heavy rainfall. If this occurs over the flood sensitive areas of central and east central WI additional significant flooding may occur. -Minor to major flooding will continue into next week with the greatest impacts expected on the Menominee and Wolf Rivers where major or record breaking flooding has been observed. -No significant precipitation is expected from Saturday through Thursday, but widespread showers and storms may return next Thursday night into Friday.
Area forecast discussion, Apr 17, 6:43 PM CDT, 15 minutes before
Area Forecast Discussion National Weather Service Green Bay WI 643 PM CDT Fri Apr 17 2026 Updated aviation portion for 00Z TAF issuance .KEY MESSAGES... -Severe storms with a risk of tornadoes (possibly strong), large hail and damaging winds are increasingly likely from 3 pm to 8 pm today, with the highest risk across central Wisconsin. -Thunderstorms this afternoon and evening will produce locally heavy rainfall. If this occurs over the flood sensitive areas of central and east central WI additional significant flooding may occur. -Minor to major flooding will continue into next week with the greatest impacts expected on the Menominee and Wolf Rivers where major or record breaking flooding has been observed. -No significant precipitation is expected from Saturday through Thursday, but widespread showers and storms may return next Thursday night into Friday. && .DISCUSSION... Issued at 125 PM CDT Fri Apr 17 2026 Severe Thunderstorm and Flood Potential This Afternoon/Evening... Confidence is increasing in a significant, but fairly brief severe weather event. A narrow axis of SBCAPE (1500-2500 j/kg) was already developing ahead of a strong cold front over SE MN, NE IA and SW WI. This was coincident with 0-1km SRH of 200-250. Radar showed pre-frontal convection occurring in far SW WI and NE IA, with additional storms developing along the cold front in eastern MN. CAMs show intense convection, including supercells and line segments moving through the forecast area between 3 pm and 8 pm. Given the degree of shear, an all-hazard event, including tornadoes, is expected, with the tornado threat lessening for any storms nearing the lakeshore, where less instability will be present. A Tornado Watch has been issued along and south of Hwy 29 (away from Lake Michigan) through 8 pm. A lingering Severe Thunderstorm Watch is also still in effect for far NC WI until 5 pm. This will be a fairly short-lived event, as instability drops off rapidly after sunset. An additional band of light to moderate showers will accompany the cold front later this evening and overnight. Expect most locations to see between 0.50 and 1 inch of precipitation with event, which will exacerbate ongoing flooding. A Flood Watch remains in effect for all but the far northwest part of the CWA. The cold frontal passage will bring a period of cooler weather through the weekend into early next week. The best chance of precipitation during this period will be 20-40 percent chance of snow/rain showers over C/EC WI on Sunday, in association with a short-wave trough and cold frontal passage. Mainly dry and warmer weather is expected for the middle of next week, with high temperatures reaching into the 60s and 70s. An approaching cold front brings another potentially significant round of showers and storms Thursday night into Friday. && .AVIATION...for 00Z TAF Issuance Issued at 636 PM CDT Fri Apr 17 2026 Strong thunderstorms were moving across portions of central and northeast WI, producing very low visibilities in heavy rain and hail. Strong winds over 40 knots were possible. The showers and thunderstorms should end from west to east later this evening into the overnight hours as a strong cold front moves across the region. Low level wind shear from the south/southeast around 50 knots will continue until the front passes. Gusty west to northwest winds are expected behind it along with a brief period of MVFR CIGS across the entire area, possibly IFR CIGS across the north. Conditions should improve into the VFR category on Saturday with gusty winds continuing into Saturday evening before winds begin to subside. && .HYDROLOGY... Issued at 125 PM CDT Fri Apr 17 2026 A Flood Watch is in effect through tonight, due to an expected half inch to an inch of rain from thunderstorms this afternoon and evening. Locally higher amounts are possible. Flooding continues along multiple rivers due to the combination of snow melt and recent heavy rainfall, including major flooding along the Wolf and Menominee Rivers. If you live near a river or stream, continue to monitor the latest hydro forecasts and Flood Warnings from the National Weather Service in Green Bay. && .GRB WATCHES/WARNINGS/ADVISORIES... Flood Watch through Saturday morning for WIZ011>013-019>022-030- 031-035>040-045-048>050-073-074. && DISCUSSION.....Kieckbusch AVIATION.......Eckberg HYDROLOGY......Kieckbusch
Hazardous weather outlook, Apr 17, 1:54 PM CDT, 5 hours 4 minutes before
Hazardous Weather Outlook National Weather Service Green Bay WI 154 PM CDT Fri Apr 17 2026 WIZ005-010>013-018>022-030-031-035>040-045-048>050-073-074-181900- Vilas-Oneida-Forest-Florence-Northern Marinette County-Lincoln- Langlade-Menominee-Northern Oconto County-Door-Marathon-Shawano- Wood-Portage-Waupaca-Outagamie-Brown-Kewaunee-Waushara-Winnebago- Calumet-Manitowoc-Southern Marinette County- Southern Oconto County- 154 PM CDT Fri Apr 17 2026 This Hazardous Weather Outlook is for north-central and northeast Wisconsin. .DAY ONE...This Afternoon and Tonight Thunderstorms, some severe with locally heavy rain, will impact the area between 3 pm and 8 pm. Hazards include large hail, a few tornadoes, possibly strong, and damaging winds. The highest threat is across central Wisconsin. Flooding may occur with the storms, especially in urban areas, and locations already impacted by heavy rain earlier in the week. River flooding is expected to continue due to recent heavy rainfall, with major flooding on parts of the Wolf and Menominee Rivers. .DAYS TWO THROUGH SEVEN...Saturday through Thursday Flooding will continue on some area rivers and streams into next week. .SPOTTER INFORMATION STATEMENT... Spotters are requested to report any severe weather or flooding to the National Weather Service in Green Bay. LMZ521-522-541>543-181900- The Bay of Green Bay south of a line from Cedar River MI to Rock Island Passage-Lake Michigan from Washington Island to Sheboygan- 154 PM CDT Fri Apr 17 2026 This Hazardous Weather Outlook is for portions of northwest Lake Michigan and the waters of Green Bay. .DAY ONE...This Afternoon and Tonight Areas of dense fog are expected through late tonight. A Dense Fog Advisory is in effect for the Lake Michigan nearshore waters and the bay of Green Bay. Thunderstorms will occur later this afternoon and evening. Any thunderstorms could be hazardous to boaters. .DAYS TWO THROUGH SEVEN...Saturday through Thursday The probability for widespread hazardous weather is low. Kieckbusch
In the hours before
Local storm report, Apr 17, 5:40 PM CDT, 1 hour 18 minutes before
Preliminary Local Storm Report
National Weather Service Green Bay WI
540 PM CDT Fri Apr 17 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0538 PM Funnel Cloud 1 NNW Phlox 45.05N 89.01W
04/17/2026 Langlade WI 911 Call Center
call center called to report a funnel cloud
going north east of Phlox.
&&
JFLocal storm report, Apr 17, 5:42 PM CDT, 1 hour 16 minutes before
Preliminary Local Storm Report
National Weather Service Green Bay WI
542 PM CDT Fri Apr 17 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0540 PM Funnel Cloud 4 WNW Elton 45.17N 88.92W
04/17/2026 Langlade WI 911 Call Center
Langlade dispatch called saying funnel cloud
seen southwest of Elton.
&&
JFLocal storm report, Apr 17, 6:20 PM CDT, 38 minutes before
Preliminary Local Storm Report
National Weather Service Green Bay WI
620 PM CDT Fri Apr 17 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0619 PM Funnel Cloud 2 SSW White Lake 45.13N 88.78W
04/17/2026 Langlade WI 911 Call Center
Call from Shawano county dispatch reporting
funnel cloud by white lake.
&&
JFLocal storm report, Apr 17, 6:25 PM CDT, 33 minutes before
Preliminary Local Storm Report
National Weather Service Green Bay WI
625 PM CDT Fri Apr 17 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0625 PM Flash Flood 1 NW Marshfield 44.67N 90.17W
04/17/2026 Wood WI 911 Call Center
getting reports of cars stuck in water on
several streets with in Marshfield.
&&
JFSpecial weather statement, Apr 17, 6:26 PM CDT, 32 minutes before
Special Weather Statement
National Weather Service Green Bay WI
626 PM CDT Fri Apr 17 2026
WIZ030-031-035-036-180030-
Shawano WI-Wood WI-Marathon WI-Portage WI-
626 PM CDT Fri Apr 17 2026
...STRONG THUNDERSTORMS WILL IMPACT WOOD...PORTAGE...SOUTHEASTERN
MARATHON AND WESTERN SHAWANO COUNTIES THROUGH 730 PM CDT...
At 626 PM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Mosinee to 12 miles north of Wisconsin
Rapids to Babcock. Movement was northeast at 45 mph.
HAZARD...Wind gusts up to 50 mph and half inch hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor hail damage to vegetation is
possible.
Locations impacted include...
Wausau, Stevens Point, Wisconsin Rapids, Weston, Rib Mountain,
Mosinee, Whiting, Bevent, Wittenberg, and Pittsville.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
These storms may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.
A Tornado Watch remains in effect until 800 PM CDT for central, north
central and northeastern Wisconsin.
&&
LAT...LON 4459 9011 4488 8983 4503 8923 4503 8910
4481 8900 4468 8914 4468 8923 4460 8922
4434 8949 4425 9032 4430 9032
TIME...MOT...LOC 2326Z 241DEG 41KT 4483 8968 4457 8982 4431 9014
MAX HAIL SIZE...0.50 IN
MAX WIND GUST...50 MPH
KieckbuschSpecial weather statement, Apr 17, 6:43 PM CDT, 15 minutes before
Special Weather Statement
National Weather Service Green Bay WI
643 PM CDT Fri Apr 17 2026
WIZ010-018-180015-
Oneida WI-Lincoln WI-
643 PM CDT Fri Apr 17 2026
...A STRONG THUNDERSTORM WILL IMPACT NORTHWESTERN LINCOLN AND WESTERN
ONEIDA COUNTIES THROUGH 715 PM CDT...
At 643 PM CDT, Doppler radar was tracking a strong thunderstorm over
Tripoli, or 26 miles west of Rhinelander, moving northeast at 50 mph.
HAZARD...Wind gusts up to 40 mph and penny size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor hail damage to vegetation is
possible.
This strong thunderstorm will be near...
Willow Reservoir around 655 PM CDT.
Other locations impacted by this storm include Mc Naughton, Lower
Tomahawk River Natural Area, Harshaw, Hazelhurst, Woodruff, Clifford,
Tomahawk River Pines Natural Area, Clear Lake Campground, Indian
Mounds Campground, and Mccord.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
A Tornado Watch remains in effect until 800 PM CDT for north central
Wisconsin.
A Severe Thunderstorm Watch remains in effect until 800 PM CDT for
north central Wisconsin.
&&
LAT...LON 4562 9004 4590 8972 4590 8969 4576 8947
4542 8994 4549 9005
TIME...MOT...LOC 2343Z 222DEG 54KT 4555 8996
MAX HAIL SIZE...0.75 IN
MAX WIND GUST...40 MPH
MPCThe office that day
Everything else NWS Green Bay, WI issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 16, 8:36 PM CDT | Dense Fog Advisory | GRB | Brown, Calumet, Door, Forest, Kewaunee, Langlade and 9 more | 12 hr |
| Apr 16, 8:37 PM CDT | Marine Dense Fog Advisory | GRB | 31 hr | |
| Apr 17, 2:56 AM CDT | Small Craft Advisory | GRB | 31 hr | |
| Apr 17, 2:53 PM CDT | Severe Thunderstorm Warning | GRB | Marathon, Wood | 82 min |
| Apr 17, 3:00 PM CDT | Tornado Warning | GRB | Wood | 60 min |
| Apr 17, 3:27 PM CDT | Severe Thunderstorm Warning | GRB | Wood | 48 min |
| Apr 17, 3:40 PM CDT | Special Weather Statement | GRB | Lincoln | 65 min |
| Apr 17, 3:52 PM CDT | Severe Thunderstorm Warning | GRB | Marathon, Portage, Wood | 53 min |
| Apr 17, 4:10 PM CDT | Flash Flood Warning | GRB | Marathon, Wood | 5 hr |
| Apr 17, 4:11 PM CDT | Special Weather Statement | GRB | Winnebago | 34 min |
| Apr 17, 4:19 PM CDT | Severe Thunderstorm Warning | GRB | Oneida | 24 min |
| Apr 17, 4:21 PM CDT | Tornado Warning | GRB | Marathon | 39 min |
| Apr 17, 4:36 PM CDT | Severe Thunderstorm Warning | GRB | Lincoln | 39 min |
| Apr 17, 4:44 PM CDT | Tornado Warning | GRB | Marathon | 32 min |
| Apr 17, 4:48 PM CDT | Tornado Warning | GRB | Lincoln | 21 min |
| Apr 17, 4:50 PM CDT | Severe Thunderstorm Warning | GRB | Langlade, Lincoln | 30 min |
| Apr 17, 4:52 PM CDT | Tornado Warning | GRB | Langlade, Lincoln | 30 min |
| Apr 17, 5:00 PM CDT | Severe Thunderstorm Warning | GRB | Lincoln, Oneida | 45 min |
| Apr 17, 5:06 PM CDT | Tornado Warning | GRB | Langlade, Marathon, Shawano | 39 min |
| Apr 17, 5:14 PM CDT | Tornado Warning | GRB | Wood | 61 min |
| Apr 17, 5:19 PM CDT | Severe Thunderstorm Warning | GRB | Forest, Langlade, Oneida | 18 min |
| Apr 17, 5:24 PM CDT | Special Weather Statement | GRB | Vilas | 36 min |
| Apr 17, 5:27 PM CDT | Severe Thunderstorm Warning | GRB | Langlade, Marathon, Menominee, Portage, Shawano, Waupaca | 37 min |
| Apr 17, 5:28 PM CDT | Tornado Warning | GRB | Vilas | 17 min |
| Apr 17, 5:30 PM CDT | Tornado Warning | GRB | Langlade, Menominee | 45 min |
| Apr 17, 5:48 PM CDT | Tornado Warning | GRB | Shawano | 9 min |
| Apr 17, 5:58 PM CDT | Severe Thunderstorm Warning | GRB | Vilas | 32 min |
| Apr 17, 6:06 PM CDT | Tornado Warning | GRB | Langlade, Oconto | 28 min |
| Apr 17, 6:26 PM CDT | Special Weather Statement | GRB | Marathon, Portage, Wood | 64 min |
| Apr 17, 6:43 PM CDT | Special Weather Statement | GRB | Oneida | 32 min |
| Apr 17, 6:52 PM CDT | Flash Flood Warning | GRB | Langlade, Marathon, Menominee, Shawano | 2 hr |
Nearby
Severe Thunderstorm Warnings in Wisconsin, 2026Every severe thunderstorm warning in 2026
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.