textproduct: La Crosse

KEY MESSAGES

- Temperatures remain in a roller coaster pattern into early next week: 60s for highs on Wednesday, then largely in the 40s by Friday, then back into 60s and low 70s Sunday into Monday.

- Small chances (20 to 40%) for some light rain on Thursday, otherwise mostly dry into early next week.

DISCUSSION

Issued at 1135 PM CDT Tue Mar 24 2026

Roller Coaster Temperatures Through The Weekend

As a regime of surface high pressure sits over the eastern CONUS, the Upper Mississippi Valley will remain under a broad regime of warm air advection. Because of this, temperatures tomorrow will push into the 60s to low 70s. We'll also see a gradual increase in low level moisture, increasing dew points by tomorrow afternoon. Model blends have been aggressive overall with this moisture return so have tempered this a bit for tomorrow as the low level dry air remains well entrenched across the region. A cold front is expected to move through early in the day on Thursday, quickly shifting winds to the north. This will work to cool temperatures a bit from the previous day but highs Thursday will still be in the 50s to low 60s as the more significant cold air advection will lag a bit behind the front. Temperatures will be at their coolest on Friday in the post- frontal regime as a surface high moves in from the Canadian Plains with highs only reaching into the upper 30s to mid 40s. However, similar to the current pattern, the surface high will gradually slide to the south and east, allowing for the return of southerly low level flow and overall warm air advection. Temperatures will then start back on their gradual warm up with highs by Sunday firmly back into the 60s and even flirting with the 70 degree mark for many on Monday.

Light Rain Chances Thursday, Otherwise Mostly Dry

With the warm air advection into the area, we'll also see a gradual influx of boundary layer moisture by Thursday morning. This moisture will pool along and ahead of the frontal boundary and allow for shower chances through the day with its passage. Current guidance indicates that the surface front will be largely through our local area by 18Z Thursday. It isn't until around this time that the elevated frontogenetic forcing catches up with the surface boundary and really helps to get things more organized. As such, the highest chances for rain and potentially some thunderstorms remains to our south and east where the deeper moisture, instability, and lift will be most strongly overlapped. The post frontal showers in our area likely won't provide much QPF with LREF 24.12 and NBM 25.01 probabilities for 0.05 inches of precipitation or more remain in the 10-25% range for Far Southwest Wisconsin and portions of Northeast Iowa (everywhere else remains less than 10%). Most places will likely only see a few hundreths of rain, if they see anything at all. This is good news for the area rivers currently experiencing higher flows due to the recent rapid snowmelt. Any additional rainfall from this system will likely not be enough to have any significant impacts on stream-flow. By 00Z Friday, all rain chances will have pushed southeast with the frontal boundary and the forecast turns dry. The influence from the incoming surface high pressure will keep conditions dry through the weekend with our next precipitation chances not coming until potentially early next week with the breakdown of the upper high across the southern CONUS and the overall weakening of upper level ridging. Many ensemble members in both the GEFS and EC ENS are hinting at these chances for precip but details on the precipitation will remain nebulous until we get a better picture as to how the upper level pattern will evolve through the weekend.

AVIATION /06Z TAFS THROUGH 06Z THURSDAY/

Issued at 1219 AM CDT Wed Mar 25 2026

VFR expected at both terminals (KLSE/KRST) and smaller sites across the local forecast area for the 25.06Z TAF period. Short period of LLWS possible at daybreak before stronger southwest winds mix down to the surface today, will require close monitoring of upstream PIREPs and VWPs.

Subsequent, widespread impacts possible Thursday and Thursday night with precipitation/thunder chances sagging south through the forecast area.

HYDROLOGY

Issued at 1116 AM CDT Tue Mar 24 2026

A handful of rivers continue to rise or are still running at elevated levels due to recent rapid snow melt. The Black River at Galesville continues to rise and will crest around minor flood stage tonight. The Yellow River at Necedah also continues to rise and will see minor flooding begin tonight. Very little rainfall is in the forecast over the next week to add any additional runoff into area river basins.

ARX WATCHES/WARNINGS/ADVISORIES

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