textproduct: La Crosse

KEY MESSAGES

- Other than a faster change over from rain and snow this morning early afternoon, there has been little change in the forecast from this morning. This only impacted the overall snow totals by up to 1 inch across southeast Minnesota

- As northeast winds increase into the 20 to 35 mph range with gusts of 35 to 50 mph west of the Mississippi River, blizzard conditions are expected to develop west of the Mississippi River by mid-afternoon and then continue into tonight.

- Will be watching western Wisconsin this evening to see whether there will be a need for a Blizzard Warning there for the overnight.

DISCUSSION

Issued at 117 PM CST Sun Dec 28 2025

At 12 PM, a 996 mb surface low was located over west-central Missouri. A cold front extends northeast of this surface low into southwest Wisconsin. This front is moving east about 1 to 2 hours faster than originally forecast, so the precipitation is changing a bit faster from rain to snow west of the Mississippi River. This resulted in some light snow accumulations up to 1 inch across parts of southeast Minnesota.

The radar for early this afternoon shows a developing deformation band as the warm conveyor belt continues to slowly develop from eastern Nebraska northeast toward St Cloud and the Twin Cities. Many of the CAMs and deterministic models are in good agreement that this deformation band will become more organized this afternoon and it will extend northeast from Omaha NE to Dodge Center MN and then toward Green Bay, WI. With banded structures showing up on the radar and what is showing up in the latest HREF, expect hourly snowfall rates up to 1 inch an hour in this band. This will continue through mid-afternoon and then increase again as the frontogenesis once again increases this evening from Owatonna MN to the Twin Cities to Medford. These areas look to see anywhere from 5 to 9 inches from this afternoon through midnight. There could be some localized higher amounts in Wabasha County (MN) and northern Buffalo and Trempealeau (WI) counties due to how the deformation band pivots over that area (longer residence in the higher snow rates).

During the overnight, the deformation band starts to slow shift southeast and moves out of the forecast area. This will likely result in 2 to 3 inches of snow in west-central and central Wisconsin.

This surface low is expected to rapidly deepen as it moves into Lower Michigan tonight. As this occurs, the surface pressure gradient will continue to tighten across the area tonight. Sustained winds will climb into the 20 to 35 mph range and the wind gusts will increase into the 35 to 50 mph range. With snow to liquid ratios of 15-20 to 1 from late this afternoon into tonight, the snow will be very easy to move. As a result, the Blizzard Warning still looks to be good across northeast Iowa and southeast Minnesota. There was some discussion about possibly upgrading the Winter Storm Warning into Wisconsin to a Blizzard Warning. However, the snow to liquid ratios (13-17 to 1) are a bit less there. If there was to be an upgrade later this afternoon or tonight, it would be from midnight to 6 AM time frame.

Tuesday

A shortwave trough, embedded in the northwest flow aloft, will move southeast across northern and eastern Wisconsin. As it does, warm air advection snow will likely fall across much of Wisconsin. Probabilities for snow totals of a half-inch or more range from 10 to 50 percent along and north of Interstate 94. High temperatures will be in the 20s.

New Years Eve

Another shortwave trough will move southeast, but this time it is much further west and its warm air advection snow covers Munich of our area. The probabilities of a half-inch or more range from 25 to 50 percent. With the upper level trough being further west, high temperatures will be much cooler ranging from the mid-teens to mid-20s.

Next Weekend

There is quite a bit of spreed in the grand ensemble on whether a longwave trough over the eastern CONUS and if it does, how far west will it extend. 23 percent of the Grand Ensemble keep the Upper Mississippi River Valley dry. Meanwhile, another 14 percent of the Grand Ensemble has up to a 60 percent chance of a half-inch or more of snow. The remaining members are between these 2 potential outcomes.

AVIATION /00Z TAFS THROUGH 00Z TUESDAY/

Issued at 535 PM CST Sun Dec 28 2025

Winter storm to impact both RST/LSE taf sites tonight into Monday morning. MVFR conditions may occur briefly for a couple of hours early in the taf period/this evening. However...snow will move back over the taf sites by 03z and combine with northwest wind gusting 35 to 40 knots...will cause reduced visibility and IFR/LIFR conditions tonight into early Monday morning. As the storm system moves away from the area Monday morning...conditions will improve to MVFR and eventually VFR Monday afternoon.

ARX WATCHES/WARNINGS/ADVISORIES

WI...Winter Storm Warning until noon CST Monday for WIZ017-029-033- 034-041>044-053-054. Winter Weather Advisory until noon CST Monday for WIZ055-061. Winter Storm Warning until 9 AM CST Monday for WIZ032. MN...Blizzard Warning until 9 AM CST Monday for MNZ086-087-094-095. Winter Storm Warning until noon CST Monday for MNZ096. Winter Storm Warning until 9 AM CST Monday for MNZ079-088. IA...Blizzard Warning until 9 AM CST Monday for IAZ008>010-018-019- 029. Winter Storm Warning until noon CST Monday for IAZ011. Winter Weather Advisory until noon CST Monday for IAZ030.