textproduct: La Crosse

KEY MESSAGES

- Low potential for light showers north of I-94 tonight (10-30%).

- Beyond tonight, dry weather is expected through the weekend with breezy conditions Tuesday.

- Normal to slightly above normal temperatures expected this week with a slight warm up Tuesday and again this weekend.

DISCUSSION

Issued at 1236 PM CDT Mon Oct 5 2026

Today - Tuesday: Low Potential for Showers North of I-94, Breezy Tuesday

Rather benign weather continues across the Upper Mississippi River Valley today into Tuesday. The exception is the low potential (10-30%) for some scattered showers north of I-94 tonight as a 700hPa shortwave moves through the region. There are some saturation issues as some drier air is depicted below 5-6kft in RRFS/RAP/HRRR soundings, but the forcing from the aforementioned shortwave along with warm air advection at 700hPa and saturation above the dry layer should result in some measurable rainfall. Currently expect amounts to be around 0.1" or less although the 05.12z HREF does suggest some potential for amounts to be as high as 0.25" (10-20%). The highest rainfall amounts are expected across northern Wisconsin.

Southerly winds increase Tuesday morning as a 850hPa low level jet of 35-40KT moves into the region, leading to some breezy conditions across the region. Thinking gusts upwards of 30-35mph are most probable, especially across southeast Minnesota. That said, the 05.12z HREF/REFS do suggest 50-70% probabilities for gusts to exceed 35mph though this is in contrast to the 05.13z NBM which has 10-20% probabilities for the same scenario.

Temperatures also increase Tuesday given southerly flow and warm air advection at 850hPa, resulting in highs topping out in the low to mid 70s as diurnal and mechanical mixing bring the warmer temperatures aloft to the surface. Winds diminish Tuesday afternoon/evening as the low level jet moves eastward and a surface front moves through the region.

Wednesday - This Weekend: Dry, Near to Slightly Above Normal Temperatures

Upper level northwest flow develops over the Upper Midwest through the rest of the week as longwave ridging builds across the western United States and longwave troughing situates over the eastern Great Lakes region. Little in the way of synoptic forcing appears evident along the mean northwest flow through the weekend, so precipitation potential is very low, topping out around 10-20% on Sunday. Along with the lack of synoptic forcing, little airmass change is expected through at least Friday, so temperatures are expected to remain fairly steady state behind the aforementioned surface front. Highs generally remain in the mid 60s to low 70s through Friday with little variation in the interquartile range of the various ensemble suites.

Some increased temperature variation in the ensembles comes this weekend as the upper ridge begins to shift eastward and model guidance suggests a longwave trough moves onto the west coast of the United States. An overall warming trend is depicted during this time as surface cyclogenesis occurs over the northern Great Plains associated with said trough and southerly flow advects warmer air into the Upper Midwest, though timing and placement variations of the synoptic features leads to uncertainty in the degree of warming and what temperatures will ultimately end up being. The 25th-75th percentiles for temperatures range about 10 degrees, though generally end up in the 70s. A few outlier members suggest temperatures may end up warmer or colder, but the overall signal is towards a bit of a warm up this weekend.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 648 PM CDT Mon Oct 5 2026

VFR conditions are expected throughout the period with increasing winds overnight across the region. Winds may be noticeably stronger just off the deck to around 30-40 kt, however the stronger surface winds should reduce the risk for LLWS at either TAF site. Otherwise, winds will continue to increase into the daytime hours from the south with wind gusts of 25-30 kts across the local area with highest gusts west of the Mississippi River. Thinking that valley fog should be unlikely at KLSE tonight given the strong surface and low-level winds.

ARX WATCHES/WARNINGS/ADVISORIES

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