textproduct: La Crosse

KEY MESSAGES

- Shower and storm chances return tonight into Saturday morning (30 to 60%). Severe potential is low (<10%) with these storms. - Widespread rain is likely Monday into Tuesday (70 to 90%) with the potential for localized flooding.

DISCUSSION

Issued at 1239 AM CDT Fri Sep 11 2026

Today Through Sunday: Trending Cooler with Some Storm Chances

An upper level low pressure system sitting over the northern Canadian Prairie provinces should slowly move east today. As this occurs, a weak surface front is forecast to move southeast from the Dakotas towards the Upper Mississippi River valley. This feature may be timed well with a weak shortwave on the southern periphery of the low to generate showers and storms ahead of the front. Severe thunderstorms are possible across much of Minnesota, but the severe storm threat is much lesser across our CWA. The timing of the frontal passage is not ideal for strong instability as it moves over the region early Saturday morning. A line of showers/storms may form during this time frame, but the severe storm potential will be quite low.

Mostly zonal flow is expected through this upcoming weekend and this pattern should usher in a cooler airmass over the area. Temperatures from today through Sunday should steadily decrease, with highs tomorrow in the lower 80s to upper 70s and highs on Sunday in the mid 60s to lower 70s. For those that are looking forward to Fall, the weather will sure begin to feel like it this weekend! In addition to the cooler temperatures, rain chances may start to ramp back up Sunday afternoon into the night. There are timing and location differences in the forecast model suite that does lead to some uncertainty as to where the rain will set up on Sunday. In any case, the rain showers or storms are not expected to cause flooding at this time through Sunday night.

Monday and Tuesday: Widespread Rain with the Potential for Flooding

A stronger H500 trough will move over the Northern Rockies towards the Northern Plains on Monday. With high pressure remaining over the southeastern CONUS, this will open the door for southwesterly flow to bring very rich Gulf of America moisture to the Upper Midwest. Blended ensemble forecast guidance continues to depict mean PWAT values approaching 2 inches throughout the day on Monday. A few rounds of rain are possible throughout the day, with the first likely already ongoing at daybreak. The second round arrives a bit later on Monday, mainly in the evening towards night time hours, as a cold front moves east towards the region. The combination of both rounds of rain will likely result in a good portion of the area receiving 1-2 inches of rainfall. Given the high moisture throughout the atmosphere, the potential will exist for flooding and some of the ensembles are hinting at this potential with the most extreme solutions showing rainfall amounts of 3-5 inches by Tuesday morning. How quickly the rain ends will be dependent on how quickly the drier airmass moves in behind the frontal passage, so it is not out of the realm of possibility that some locations may continue to get rain on Tuesday.

Rest of Next Week: Rain Chances Continue with Cooler Temperatures

High temperatures through at least the middle of next week are expected to remain in the 60s to 70s each day aided by the rain chances and increased cloud cover. Another potential for rain may arise on Wednesday night into Thursday as mid level moisture increases once again and potential shortwaves round the top of the upper level high over the southeastern US. With that being said, it will certainly begin to feel like Fall with the increased chances for rain along with cooler daytime highs and overnight lows throughout all of next week.

AVIATION /12Z TAFS THROUGH 12Z SATURDAY/

Issued at 616 AM CDT Fri Sep 11 2026

Foggy conditions are ongoing across many river valleys across the region. This fog will dissipate by mid-morning. VFR conditions are then expected for the rest of the TAF period. Southwest winds increase this morning with sustained winds of 10 to 20 mph and gusts of 25 to 35 mph during the afternoon and evening. The strongest winds will be in southeast Minnesota. Winds gradually decrease through the evening then begin to switch to the northwest towards the end of the TAF period for areas in southeast Minnesota as a front moves through the region Saturday morning. The rest of the region will see northwest winds by the mid-morning. A line of showers and storms will move through during the early morning hours which may cause the wind direction to be variable at times.

ARX WATCHES/WARNINGS/ADVISORIES

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