Mountain, WI Weather

This Hazardous Weather Outlook is for north-central and northeast Wisconsin.

Day one: Tonight

The probability for widespread hazardous weather is low.

Days two through seven: Friday through Thursday

The probability for widespread hazardous weather is low.

Spotter information statement

Spotter activation will not be needed tonight.

Updated aviation portion for 00Z TAF issuance

Key messages

- Spotty light rain (20-50% chances) for Halloween. Rainfall amounts less than 0.05 inch. Despite the rain, high temperatures will remain slightly above normal in the 50s.

- Low pressure brings widespread showers (60-80%) and gusty winds early next week, peaking on Election Day. At least 0.50 inch rain for most. Chances for rain lingers much of next week as the low slowly exits east.

- Above normal temperatures continue until late next week.

Discussion

Issued at 1241 PM CDT Thu Oct 29 2026

High pressure brings cooler temperatures through Friday. Fog risk tonight looks low as some wind will keep low-levels mixed enough. Could have a bit more patchy ground fog Saturday morning, though increasing clouds from the south may restrict radiational cooling needed for that.

Spotty light rain for Halloween: Deep trough set up over the eastern Pacific sends a southern stream trough toward the western Great Lakes on Saturday. Not much surface reflection as the departing high holds. However, looking at soundings there is a moist profile below 10kft with weak lift forecast, suggesting that though chances of measurable rain (0.01") will be under 50%, drizzle or very light trace amounts of rain may occur beneath a mostly cloudy sky. Ensembles support this idea showing 30-60% chance of seeing at least a trace of rain, greatest over central Wisconsin. But, not looking at any kind of washout for outdoor activities. Even with the clouds and some rain, high temperatures will still reach the mid to upper 50s which even though cooler than lately, will be above average.

Stronger system with widespread rain early next week: After some dry weather returning Sunday into start of Monday, larger scale troughing shifts across the plains and moves into the Great Lakes-Ohio Valley. Surface low is well agreed upon from ensembles from ECMWF, GFS, and Canadian to track across northern Ohio Valley, placing Wisconsin in regime that will bring periods of rain from late Monday through Wednesday as the system slowly crosses. Peak of rain and gusty winds will be Tuesday, Election Day, but unsettled weather will be slow to unwind the rest of the week behind the departing low. Chances for exceeding 0.50 inch rain Monday Night through Tuesday are up to 70%, while chances for exceeding 1.00 inch are up to 40-60%. Higher end projections take rainfall to 1.5 to 2.0 inches. Certainly looks like a soaking rain at times. Dynamics may be strong enough for some embedded thunder as the initial warm air advection rain arrives on Monday night.

Temperatures will remain above normal the next week, though a bit of a cooldown (temperatures returning to around normal) occurs late next week after the low pressure system passes by. Available long range guidance points to above normal temperatures through most of November. Official forecast for meteorological winter (Dec through Feb) also favors above normal temperatures which is right in line with the ongoing very strong El Nino.

Aviation

for 00Z TAF Issuance Issued at 547 PM CDT Thu Oct 29 2026

Winds continue to diminish rapidly early this evening as anticipated. Meanwhile, an area of MVFR CIGS slowly sinking southward across Vilas County early this evening, on the door steps of Arbor Vitae and Eagle River. It may take a few hours to reach KRHI, thus may need to adjust the KRHI TAF before issuance. Meanwhile, a mid deck of clouds across Minnesota was approaching the Wisconsin border. This area of clouds should generally remain north of Highway 29 tonight. Northwest winds 5 to 10 knots tonight into Friday morning will become light and variable Friday afternoon.

Watches, warnings and advisories

None.