textproduct: La Crosse

KEY MESSAGES

- Wintry mix along and north of I-94 still looks on track for central and northcentral WI later tonight. Some light icing could occur in the pre-sunrise hours prior to temperatures warming above freezing. Impacts should be minimal.

- Windy and warmer on Wednesday ahead of a cold front coming in. Winds could gust 40-45 mph in MN/IA, 30-40 mph elsewhere, peaking around mid-day. Temperatures should warm into the 60s before rain develops and spreads across the area from northwest to southeast in the afternoon and evening.

- More rain is looking likely Thursday night (60-80% chances) for northeast Iowa and southwest WI with amounts generally less than one-quarter inch.

- Warming into the weekend with the pattern shift toward a showery period. Periodic rain is expected but any signal for heavy rainfall is low at this time. However, with rivers running higher, especially in WI, the heavy rainfall threat should be monitored.

DISCUSSION

Issued at 1246 PM CDT Tue Apr 7 2026

Wintry Mix Tonight Near/Northeast of I-94

As low-level ridging slides east this afternoon, winds will become southerly and begin a period of strong warm advection overnight. This will keep temperatures from falling too far, with T/wet- bulb temp remaining near 32F or below overnight near and northeast of I-94. As the low-level jet increases, a convergent low-level moisture transport convergence signal develops that is isentropically lifting parcels in s-swrly flow. This convergent band oriented from NW->SE will quickly move through from 06-12Z. Initial saturdation will be challenged, but as it shifts northeast, good 07.12Z HREF consensus suggests precipitation will begin, with probabilities for precipitation increasing from La Crosse (30-40%) to Wausau (~80%). A light wintry mix of snow/sleet and freezing rain is expected near and north of I-94 based on surface T/wet-bulb temp and the warm layer of 3-4C coming in aloft. Southwest of I-94, rain would be the main type. Impacts in the mix are thought to be low with light amounts expected in the transient band and warmer springtime ground (todays sun helps). Slick roads are possible for the morning commute in central WI. This band shifts east pretty quickly Wed morning.

Windy and Warmer on Wednesday, then Rain Showers Move Through

As the aforementioned warm advection kicks in overnight, wind speeds aloft increase into the 50-60kt range at 850 mb by sunrise. Around mid-day will be the peak of the gusts, maximizing the mixing depth and stronger winds aloft to cause some gusts in the 40-45 mph range in MN/IA, lesser in WI. Wind speeds decrease as the afternoon continues, and clouds and rain showers increase, all causing less favorable mixed gust potential. Low-level theta-E convergence increases in all of the 07.12Z deterministic models as the front moves across the area from west to east, thus rain chances are higher and more widespread heading into WI. 07.12Z HREF CAMS also support this increase for WI/far northeast IA and east. A bit of instability is present for a rubble of thunder.

More Rain South of I-90 Thursday Night

The cold front that moves through Wednesday will stall to the south and be worked on with another weather system moving through in the northern stream of the split westerly flow Thursday late afternoon and night. This excites southerly low-level convergence flow into the front with strong moisture transport convergence and some instability near the I-80 corridor. Northeast Iowa and southwest WI are on the northern edge of the rain shield late Thursday afternoon and night. Amounts are expected to be less than one-quarter inch, and the northern edge could still shift but recent location trends have been stable.

Warming into the Weekend, Periodic Showers into Next Week

Good consensus exists on a pattern evolution this weekend as a longwave trough forms in the western U.S. Beginning later on Saturday, a series of weather systems are ejected through the area in southwest flow from this trough as warmth and moisture build in. Precipitable water mean values in the 07.00Z Grand Ensemble are around 1 inch and the 07.00Z ECMWF Ens EFI has a good footprint for much above normal temperatures. Thus, the ingredients are there for heavy rainfall, although right now the model spread is dominating with lower predictability (10%) for any one location receiving over an inch in 24 hours. With the recent above average rainfall (300 percent of normal) over much of the area, rivers will be running elevated, so the heavy rain potential will need to be monitored. High temperatures look to be in the 70s Sunday and Monday, with the deterministic NBM providing realistic guidance. The probabilistic NBM guidance bias-corrected members are really jacking the distribution (7F warmer on average) - so not using the probabilistic T distribution for now. The pattern breaks by mid-week it appears.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/

Issued at 1231 PM CDT Tue Apr 7 2026

Rain and snow will develop across the area overnight as a warm front moves north into the region. This will lower ceilings into the 3-6K range. As we enter the warm sector on Wednesday morning, ceilings will rise into the 10-15K range. It will also become rather windy with sustained south winds in the 15 to 20 knot range and gusts of 20-35 knots.

HYDROLOGY

Issued at 1246 PM CDT Tue Apr 7 2026

After the heavy rainfall in the last week (300-500% of normal!), many of the rivers are on their way down. In WI, where more river flooding has been seen, rivers are cresting in the lower reaches on the Black, Kickapoo, and Yellow. Standing water is noticeable in Vernon, Juneau into Monroe counties. There will be periods of lighter rain this week which should have little impact on the current rivers (generally around 0.25 inches). However, as a longwave trough sets up over the western U.S., the area will see anomalous warmth and moisture. This sets up the potential for additional heavy rainfall for Sunday and Monday, which could cause river rises again next week if realized. Confidence is low in impact-producing rains right now.

ARX WATCHES/WARNINGS/ADVISORIES

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