textproduct: La Crosse

KEY MESSAGES

- Severe Thunderstorm Watch in effect through 700 PM CDT, for all hazards including large hail (up to 2 inches in diameter), damaging winds (up to 70 mph gusts), and a few tornadoes. Risk for locally heavy rain.

- Marginal to enhanced risk for severe thunderstorms Thursday afternoon. All hazards including risk for large hail, damaging winds, and tornadoes from northeast Iowa through southwest Wisconsin.

DISCUSSION

Issued at 107 PM CDT Wed Jun 10 2026

Regional radar and surface observations early this afternoon show a Mesoscale Convective System (MCS), moving northeastward across southwest Wisconsin near the Iowa border. Several severe thunderstorm warnings are in effect with gusts up to 74 mph being reported thus far with this MCS. Convection initiation continues rapidly north of this MCS, with several discrete cells developing near the I-90 corridor. High-resolution CAM guidance and observational trends suggest thunderstorms will quickly grow upscale into a forward- propagating line through mid- afternoon into the early evening as storms track towards the I-94 corridor. Initially, discrete cells near the I-90 and I-94 corridors early this afternoon will pose the risk for large hail and strong winds, with the severe threat evolving into primarily straight line winds.

Looking ahead into the evening, a surface cold front is expected to shift southeast across the region from central Minnesota setting the stage for another round of convective development. High-solution models continue to offer varying solutions on the intensity of storms along this frontal boundary. Shear and instability profiles once again suggest discrete cells developing along the front, before growing upscale into line segments as storms move eastward towards I-94 through this evening.

Overall, low to medium confidence exists regarding the evolution of storms, particularly this evening. Ensure you have multiple ways to receive warnings today! This is especially paramount given the multiple rounds of thunderstorms through this evening.

Looking ahead to Thursday, SPC has highlighted the area for a marginal to enhanced risk for severe thunderstorms, focused from late morning through the afternoon. Thunderstorms will be capable of all hazards including the risk for large hail, damaging winds, and tornadoes from northeast Iowa through southwest Wisconsin. High-resolution models suggest an MCS will develop across Iowa by mid-morning, with storms growing upscale across the CWA by late morning through the afternoon. The greatest risk for severe weather will focus across northeast Iowa through southwest Wisconsin.

Long-term: Friday through early next week:

Relatively quieter conditions close out the week as a trough pivots into the eastern Great Lakes region, setting up zonal flow aloft over much of the northern United States. There is some potential for precipitation through the weekend, mainly on Saturday as the deterministic guidance resolves a surface boundary shifting southeastward through the Upper Mississippi River Valley associated with a 700hPa shortwave trough sinking southward from a vorticity maxima over Manitoba/Ontario. Probabilities of rainfall during this period sit around 30-60% in both NBM and LREF with the highest confidence in rainfall potential located over northeast Iowa into southwest Wisconsin.

Behind this boundary, cooler temperatures look to arrive to start the new week as another shortwave trough sinks southeastward through the United States, setting up an area of lower heights across the Upper Midwest. Plenty of variation exists regarding timing and location of this upper level feature which leads to a fairly large temperature spread in the NWP/AIWP ensemble guidance, but the consistent trend amongst these suites is towards cooler temperatures.

AVIATION /00Z TAFS THROUGH 00Z FRIDAY/

Issued at 619 PM CDT Wed Jun 10 2026

Thunderstorms have developed along and north of the I-90 corridor this evening. Heavy rain and large hail have been observed with these storms during the last few hours, with visibility as low as 1SM. Thunderstorms will continue to develop ahead of a cold front tracking eastward through Minnesota this evening, with storm activity focusing across southeast Minnesota towards the Wisconsin border through 11/0200Z. The atmosphere will begin to stabilize from 11/0200-0300Z, with storms weakening as they track into western Wisconsin. Overnight, showers and thunderstorms will exit the area. Recent rains will increase the potential for areas of patchy fog from 11/0800-1100Z, with a 20% chance for fog to reduce visibility below 3SM for KLSE and KRST. Thunderstorms return across the region by late morning into the afternoon.

ARX WATCHES/WARNINGS/ADVISORIES

WI...None. MN...None. IA...None.