textproduct: La Crosse

KEY MESSAGES

- Elevated fire weather conditions are expected today due to breezy and dry conditions.

- Slightly above normal temperatures expected today cease by Tuesday with below normal temperatures returning. Frost potential for some Tuesday through Friday nights.

- Precipitation/meager storm chances (20-30%) this afternoon/evening with low rain chances (30%) returning by Thursday afternoon. Otherwise, generally dry conditions areawide.

DISCUSSION

Issued at 148 PM CDT Mon May 4 2026

Today - Tonight: Elevated Fire Weather, Some Storm Chances South

A surface cold front is currently draped across the local area, slowly sliding southeast through the afternoon. Behind the front, winds are shifting to a northwesterly direction which is dragging in some drier air in the low to mid levels, creating some elevated fire weather concerns. Even with some mid and high clouds across the northern half of the region, mixing remains plentiful with RHs continuing to fall to between 20-35%. The main limiting factor preventing concerns from increasing remains the substantial green up from a record breaking wet April. Wind gusts will continue to between 25-35 mph through the afternoon before the nocturnal inversion begins to set up, effectively ceasing mixing.

As the front continues to drop south through the afternoon, southwesterly winds out ahead of the boundary are keeping some low level moisture present across portions of Northeast Iowa and Southwest Wisconsin. Early this afternoon, a cumulus field has already developed across this region but agitated cumulus remain at bay with capping holding firm. Current hi-resolution guidance has continued to hold any substantial convection south/east of our area across the warm sector. Any storms that do form would be very high based with LCLs up around 700 mb (roughly 3 km). Inverted-V soundings and DCAPE values around 800-1000 J/kg indicate the potential for some strong wind gusts from downdrafts should any storms be able to fully mature. However this is looking less likely for our area. We will see additional chances for some precipitation as the elevated front sweeps through later this evening and interacts with the more ample mid-level moisture present across the region. This would likely be confined to a similar region (NE Iowa and SW Wisconsin) and shouldn't provide much in the way of accumulations (perhaps a few hundreths of an inch).

As winds finally start to decrease later this evening and into the overnight hours, temperatures will drop into the 30s to low 40s. Given that the lack of moisture will likely make it quite difficult to condense into anything for frost and a lack of widespread freezing temperatures, have held off on any headlines for the time being.

Tuesday - The Weekend: Relatively Benign Pattern

A strong upper low is expected to sit and spin over Ontario and the Hudson Bay for much of this work week, keeping our region under northwest flow aloft. At the surface, a drier air mass will continue to seep into the region with a weak surface high dropping into the Plains by midweek. This, along with continued northwesterly surface flow will prevent any sort of appreciable moisture return. As such, our forecast will remain dry through Thursday. A weak shortwave will pass overhead late in the week and give rise to some low rain chances, mainly along and east of the Mississippi River. Given the weak forcing and minimal moisture return by that point, are not expecting this to amount to much overall with minimal QPF returns forecasted thus far. This trend continues into the weekend with dry conditions expected through Sunday before some low rain chances return for southern portions of the area. Persistent west/northwest surface flow into the weekend will work to keep the boundary layer pretty dry across the Upper Midwest this week, a nice reprieve from the hectic and soggy April we had.

High temperatures will also be slow to climb out of the 50s and 60s with highs not even flirting with the 70 degree mark until Saturday. Low temperatures will fall to right around freezing most nights with the dry conditions and light winds so frost/freeze headlines may be needed for at least portions of the area Tuesday night through Friday night.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1232 PM CDT Mon May 4 2026

A cold front will move southeast through southern Wisconsin and eastern Iowa this afternoon. Scattered showers and storms are expected to develop in these areas. A few of these storms may become strong. This will be south and east of the TAF sites. Both of them will see mid- and high clouds through this evening.

For this afternoon, northwest winds will be sustained in the 15 to 20 knot range with gusts of 20 to 30 knots. With the loss of diurnal heating and a relaxing surface pressure gradient, northwest winds will decrease less than 10 knots tonight.

ARX WATCHES/WARNINGS/ADVISORIES

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