textproduct: La Crosse

KEY MESSAGES

- Other than a couple periods of low precipitation potential, mostly dry conditions are expected through the end of the week.

- Near to slightly above normal temperatures through Friday with a brief warm up to well above normal this weekend.

- Higher precipitation potential returns early next week.

DISCUSSION

Issued at 103 PM CDT Tue Oct 6 2026

Today - Friday: Mostly Dry, Near to Slightly Above Normal Temps

Northwest flow continues across the region through the end of the week with little synoptic forcing expected to traverse the mean flow resulting in an overall dry forecast for the area. That said, there are two periods of interest from a precipitation perspective: Wednesday night into Thursday morning and Friday.

During the first period, model guidance depicts increasing 700- 500hPa differential positive vorticity advection sneaking into northern Wisconsin which could spark some scattered showers. The main point of uncertainty is a lack of saturation given dry air below 6-7kft due to fairly deep mixing expected Wednesday afternoon. CAM guidance also keeps the bulk of any precipitation north of our area while the 06.12z HREF/REFS suggest a 10-30% chance for those north of I-94. As of right now, have tended towards a dry forecast given the issues with the dry air.

The second period is also a bit uncertain. Southerly flow developing across the central Great Plains on Friday gives way to an 850hPa low level jet and associated warm air advection/moisture transport that have the potential to nose into the Upper Mississippi River Valley. However, ensemble guidance is a bit varied on the location of precipitation associated with this feature, if it develops at all. The European model suite is the most excited regarding precipitation probabilities (30-50%) given a further northward placement of the low level jet whereas the the GEFS/AIGEFS/GEPS solutions tend a little drier across our area (10-20%) and keep precipitation largely to our south. Have stuck with the 06.13z NBM solution which is more in line with the GEFS/AIGEFS/GEPS at 10-20%, but if a clear northward trend is noted then probabilities will likely increase.

Outside of the low potential for precipitation through the rest of the week, a weak surface front moving through the region today/tonight will shift our winds to the northwest and usher in some slightly cooler temperatures for Wednesday and Thursday. Depending on how far northward the low level jet is able to make it, a warming trend may be able to start as early as Friday which is currently the favored solution of the 06.13z NBM.

This Weekend - Early Next Week: Brief Warm Up, Precipitation Potential Returns

The upper level synoptic pattern begins to break down this weekend as ridging across the western United States begins to shift eastward while model guidance depicts a longwave trough moving onshore the West Coast. Rising heights associated with the approaching ridge and the aforementioned southerly flow associated with cyclogenesis occurring as the trough moves onshore should lead to a bit of a warm up by this weekend with the 06.13z NBM mean suggesting temperatures climb into the mid to upper 70s areawide Saturday, 15-20 degrees above normal for this time of year, while some locations possibly reach 80 degrees (40-60%). Fairly little spread exists in the 25th-75th percentiles of the NBM membership, backed up by other ensemble suites such as the GEFS/EPS/GEPS and their AI equivalents, so confidence in these warmer temperatures is high.

Heading into early next week, the potential for precipitation returns to the Upper Midwest, but confidence in the overall forecast is not very high at this point as quite a bit of variability exists amongst the previously mentioned ensemble suites regarding timing and location of precipitation. That said, a fair number of members do suggest there is some potential for precipitation to start off the new week, so have continued with the 06.13z NBM mean which is around 20-50%. Cooler temperatures also look to make a return, falling back towards normal by Tuesday.

AVIATION /00Z TAFS THROUGH 00Z THURSDAY/

Issued at 635 PM CDT Tue Oct 6 2026

VFR conditions are expected throughout the period with winds shifting to northwesterly this evening as a surface front passes through the region. Winds will remain northwesterly throughout much of the TAF period, increasing to around 8-12 kts during the afternoon on Wednesday. Given the northwesterly surface winds overnight, local research would suggest this is an unfavorable wind direction for valley fog at KLSE.

ARX WATCHES/WARNINGS/ADVISORIES

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