Tomah, WI 54660 Weather

Key Messages

- Small (10-20%) chance for a light shower north of Interstate 90 this afternoon and evening and again late Saturday into early Sunday.

- Quite a bit of uncertainty for early next week with potential for widespread rain in our region, nothing at all, or rain for just some of us. Regardless, temperatures trend cooler and towards normal through the beginning of next week.

Discussion

Issued at 110 AM CDT Fri Oct 23 2026

This Evening and Late Saturday: Low Potential for Light Rain

This afternoon/evening, weak shortwave looks to ride the upper ridge that has been keeping us warm and dry. This feature, along with some modest moist advection at 850mb, could (10-20% per 23.00z NBM/HREF and 22.12z LREF) produce a light shower as the shortwave passes over areas north of Interstate 90. No hazards are expected.

Moving into the weekend, strong northern stream upper low barrels eastward over Canada with the associated cold front pushing south through the Upper Midwest. However, with this feature failing to phase with a southern stream upper low that looks to linger over the Four Corners, the front will eventually stall somewhere near our CWA. As this occurs, mid-level moisture will continue to be advected northward on the western side of a ridge centered in the Ohio Valley. Thus, as weak shortwaves eject northeast from the Four Corners upper low, some light rain could result given the combination of modest cooling aloft, mid level moisture, and lift associated with the stalled front. Think its a pretty good bet some spots will pick up some rain but most guidance keeps best moist fetch just to our northwest. Have therefore carried some low (10- 20%) PoPs in our area for now.

Sunday - Wednesday: Greater Precipitation Potential, Trending Cooler

Greater precipitation potential exists Monday through Tuesday as the cutoff low across the Desert Southwest begins to lift northward. How this feature evolves as it moves northward and where the heaviest rainfall associated with it will occur remains rather uncertain though. The GEFS/AIGEFS members largely suggest the low takes a more southern trajectory, keeping higher probabilities for precipitation across a majority of the Upper Mississippi River Valley (60-80%) whereas the EPS/AIFS Ens on the other hand suggest a more northern and western solution, keeping higher probabilities across Minnesota into northern Wisconsin. Given the uncertainty, probabilities for precipitation remain on the lower end, currently sitting around 30- 40% in the 23.01z NBM though these probabilities may increase as the models begin to converge on a solution.

Aviation

Issued at 1225 PM CDT Fri Oct 23 2026

VFR conditions expected for the next 24 hours at the terminals. A band of light showers is moving east northeast through South Central Minnesota early this afternoon and is expected to impact the KRST terminal over the coming hours. Upstream observations show light rain with this activity so visibilities and CIGs should stay at or above VFR thresholds. Southerly winds will continue through the period with gusts expected through the afternoon at the KRST terminal. Gusts should taper off by this evening but sustained speeds will remain elevated between 8-15 kts before gusts return late tomorrow morning.

Arx Watches

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