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 Monday 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 436 AM CDT Mon May 4 2026

The widespread above normal temperatures come to an end today as a frontal boundary sags southeast through the forecast area causing a 15-20 degree spread in forecasted daytime highs. An earlier progression to the frontal passage in HREF member runs has decreased extent and degree of local warmth today, currently expected in southern peripheral counties from northeast Iowa into southwest Wisconsin. Some temporal discontinuities within recent HRRR runs regarding exact placement suggests some shifting northwest- southeast remains possible mostly dependent on coinciding diurnal heating influence; i.e., later passage, warmer temperatures build farther northwest through the forecast area.

Otherwise, limited impacts from light, low precipitation chances with frontal passage. Similar to temperatures, exact timing of frontal passage remains the inherent discrepancy with a 3 - 5 hour window between HREF members and the NBM hourly PoPs at the current forecast hour. Therefore, have painted more widespread than will be realized 15% to cover the timing spread while the actual timing will be limited to 1 hour +- 30 minutes for much of the area when saturation manages to successfully overcome the ongoing lower level dry air outside of southwest Wisconsin into northeast Iowa where PoPs likely linger within the warm sector. While also dependent upon frontal boundary location, current forecast confidence for local storm chances, potentially strong to severe upon initiation before quickly exiting the local forecast area, limited to far southern peripheral counties (Clayton County, IA & Grant County, WI) primarily.

Given the expected light rain amounts, with warm and breezy conditions expected today, elevated fire weather conditions are expected as RH values will probably (50-80% per 04.00z REFS) dip below 30 percent. Any rain should simply delay and mute the RH falls a bit due to expected light amounts. Limiting factors for fire weather conditions today look to be sky cover limiting mixing and the fuels which, while still in a transition state, are getting pretty green out there.

Slightly cooler low level temperature trends within LREF members have resulted in slightly (1-2 degree) cooler temperatures through the week than previously forecasted with daytime highs in the mid 50s for most Tuesday through Friday. More impactful overnight frost and/or freeze potential affects slightly more of southeast Minnesota locally initially Monday night, becoming widespread Tuesday night through Thursday night.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 601 AM CDT Mon May 4 2026

VFR conditions will prevail over the next 24 hours with a small (15-30%) chance for brief MVFR due to TS southeast of a CCY-82C line between 18z and 00z. Gusts to around 30 knots out of the southwest will develop by mid-morning and then slowly turn clockwise to out of the northwest by 21z.

ARX WATCHES/WARNINGS/ADVISORIES

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