textproduct: La Crosse

KEY MESSAGES

- A cold start to the week with temperatures 10 to 15 degrees below normal for today and Tuesday. Lows tonight fall into the teens, possibly even a few single digit readings towards central Wisconsin.

- Passing light snow showers today, mainly east of the Mississippi River. No snow accumulation or impacts expected.

- Light rain/snow Tuesday night into Wednesday morning, followed by more widespread rain Wednesday night. Most areas should see less than an inch (<10% chance of exceeding 1").

- The potential exists for more rounds of rain into the weekend, possibly heavy as we look into early next week.

DISCUSSION

Issued at 1200 AM CDT Mon Apr 6 2026

Today - Tuesday: Colder, Scattered Snow Showers Today

Colder air is filtering southward in the wake of our cold front that swept through this past evening, setting the stage for a chilly start to the new week. Boundary layer lapse rates steepen quickly around or shortly after sunrise due to ongoing differential cold air advection and many HREF members show upright instability in place by mid-morning. Despite surface temps rising into the mid to upper 30s by the afternoon, the aforementioned steep lapse rates and wet-bulb values at or below zero will allow any convectively generated snow showers to penetrate to the surface at warmer temperatures that one might expect.

Explicit reflectivity progs from the various CAMs show isolated coverage of these showers at best, likely owing to the increasing subsidence off an approaching high to the northwest. Therefore, have only gone with low (10-20%) coverage PoPs, highest into central Wisconsin where the MAUL extends up into the DGZ. Not expecting any accumulations from these showers and therefore no impacts to travel.

As the aforementioned surface high approaches this afternoon, showers should wane and skies clear for tonight. There is high confidence (>80%) that lows crater into the teens under this setup. Still cannot rule out single digit readings (20-40% chance) in favored locales in central Wisconsin such as the sand bogs.

Tuesday Night - Wednesday Night: Several Rounds of Precip

A ribbon of isentropic upglide/theta-e advection lifts northward on the backside of the departing ridge Tuesday evening, fueling a band of light precipitation. The big question is exactly what precipitation type is realized at the surface, a function of how soon the precip starts and how quickly surface temperatures can rise above freezing. The EPS members are slightly cooler at onset and start the precip as snow for more of the region, whereas the warmer GEFS members keep the risk for snow more confined into Wisconsin.

Either way you slice the forecast, the impacts from any snow look to be negligible with warm ground temperatures and warming surface temperatures through the night. Towards central Wisconsin, there is a faint signal that the above freezing warm nose could arrive before surface temperatures respond, resulting in a brief window of freezing rain. Again, with ongoing warm air advection and the window of opportunity looking to be a few hours at best, impacts from freezing rain should be minimal to none.

Most of the day on Wednesday could be on the dry side with a few pop-up showers possible in the warm sector before a cold front approaches in the afternoon. With the mid to upper-level flow parallel to the frontal orientation, there could be some training storm motions along the front as it moves through. However, with the overall progressive motion of the front and limited mid-level moisture, rainfall amounts from this line are not expected to be overly impactful with a <10% chance of exceeding 1" from the various NBM ensemble members.

End of the Week into Early Next Week: Heavy Rain Threat

Shifting later into the week as the upper level pattern takes on more of a zonal orientation, confidence remains low on the exact placement of the surface baroclinic zone, which will play heavily into the trajectory and strength of the later week storms. Trends over the last 24 hours have favored keeping the heaviest rain south of the forecast area for Thursday through Saturday, but being 5 days out, this boundary could still wobble northward.

Moving into the Sunday to Monday (April 12-13) timeframe, there is an increasing signal for a stronger synoptic system to impact the region and bring widespread moderate to heavy rain to the north central CONUS. With this system being 7 to 8 days out, plenty can still change in the forecast, but the consistent signal in the global models at this time range is noteworthy.

AVIATION /06Z TAFS THROUGH 06Z TUESDAY/

Issued at 1243 AM CDT Mon Apr 6 2026

MVFR stratus over central and southern Minnesota will continue shifting southeastward overnight, bringing MVFR restrictions to the area. Some low potential for IFR ceilings remains for those west of the Mississippi River and at higher elevations, but probabilities for IFR restrictions remain 10-20% in the NBM. Ceilings begin to lift through the morning hours, becoming VFR in the afternoon.

Northwest winds will continue across the region with gusts of 20-25KT during the morning to early afternoon before diminishing into the evening hours. Isolated snow showers along and east of the Mississippi River remain possible during the late morning into the afternoon as well. Outside of brief visibility reductions, impacts associated with these showers will be minimal.

HYDROLOGY

Issued at 1200 AM CDT Mon Apr 6 2026

Crests continue to work downstream along the Black, Kickapoo, Lemonweir, Wisconsin, and Yellow rivers. With little rainfall expected before Wednesday afternoon, the overall forecasts should remain more or less on track. By the time the midweek rainfall arrives, a number of locations should have crested. Therefore, the impacts from any rain midweek will likely only delay the fall of the rivers rather than result in secondary crests. It remains too soon to see how the potential for heavy rain later in the upcoming weekend would impact the rivers.

ARX WATCHES/WARNINGS/ADVISORIES

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