textproduct: La Crosse

KEY MESSAGES

- Below normal temperatures for the remainder of the week, warming back to around average on Saturday.

- The risk for near freezing early morning temperatures continues for Thursday and Friday, focused mainly east of the Mississippi River.

- A few rounds of light showers pepper the area through the end of the week, but the vast majority of the forecast period through Saturday afternoon looks dry.

DISCUSSION

Issued at 1238 AM CDT Wed May 6 2026

Today: Quiet Overall

A 1022-mb surface high pressure slides to the south of the region today, though its influence will still drive today's weather. With 800-mb temperatures of -10C during peak heating, a thicker CU deck is progged to form by mid to late morning and persist into the evening. The HRRR/RAP forecast profiles show deeper saturation and potential upright instability to fuel light showers towards northern Wisconsin, but profiles quickly mix out as one approaches I-94. Today should be the coldest day for at least the next week with highs struggling to reach 50 in some spots given the cold air advection and thicker clouds.

Thursday - Friday: Warmer, A Few Passing Showers

By early Thursday morning, the region shifts under the western flank of the mean longwave trough that has been bringing our bout of colder weather. A mid to upper tropospheric wave propagates through Thursday morning and serves as the focus for light shower activity in the morning to early afternoon hours. The main question revolves around the depth of the mid-level moisture plume that accompanies this wave passage. The global ensembles are more bullish with this moisture and QPF footprint, while the CAMs are more reserved/mixed and variable in their QPF coverage. Have nudged up the PoP forecast for morning hours but kept values contained at 20-30% and east of the Mississippi River for now. In either case, the overall impacts from these showers look to be minimal.

Trends for Friday have been for the higher mid-level theta-e airmass to stay farther south, taking the risk of showers with it. There are an increasing number of ensemble members that keep the rain completely south of the area and the official forecast will likely turn dry if this trend continues.

The passage of the wave early Thursday morning throws a wrinkle into the temperature forecast for frost/freeze potential for Thursday morning. While confidence is higher along and north of I-94 that we will see another freeze, areas to the southwest of this line may stay too cloudy and warm to have a frost. A look at some of the raw model output shows this scenario, with the big unknown being the exact timing of the wave, which will have a domino effect on temperatures.

The Weekend: Warmer to Start, More Rain Chances

As the aforementioned dome of cold air finally exits the region, 850 mb thermal ridging will start to move into the Upper Midwest by the weekend. Low level warm air advection looks meager overall but should still be enough to help temperatures reach into the upper 60s to lower 70s by Saturday afternoon, especially across Northeast Iowa. A cold front is then expected to drop down into the region late Saturday into Sunday, bringing the best chances for rain with its passage. There are still many details that will need to be ironed out ahead of this with plenty of synoptic uncertainty at this time. Not sure if this is going to provide much relief to the dry conditions as moisture return remains on the low side ahead of this frontal passage but this will be monitored going forward. Post frontal temperatures will be near normal in the 60s for the start of the next work week.

AVIATION /06Z TAFS THROUGH 06Z THURSDAY/

Issued at 1238 AM CDT Wed May 6 2026

VFR conditions with northwesterly winds continue for another 24 hours. Abundant cumulus around 4-5 kft is expected during the afternoon today but ceilings should remain above 3 kft.

ARX WATCHES/WARNINGS/ADVISORIES

WI...Frost Advisory until 8 AM CDT this morning for WIZ032-041- 053>055-061. Freeze Warning until 8 AM CDT this morning for WIZ017-029-033- 034-042>044. MN...Frost Advisory until 8 AM CDT this morning for MNZ079-086>088- 094>096. IA...Frost Advisory until 8 AM CDT this morning for IAZ008>011-018- 019-029-030.