Southeast Wisconsin winter storm to bring strong winds, rain, ice, and snow

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MILWAUKEE - A strengthening low-pressure system looks to bring wild weather to Wisconsin Saturday night through Monday. Significant impact from potential strong storms, ice, snow, and strong winds.

The National Weather Service has issued a Winter Storm Watch from 7 p.m. Saturday through 4 p.m. Monday for much of the state. Other areas to the west are under winter storm warnings and even blizzard warnings as far west as Montana to as far east of the Upper Peninsula of Michigan and most of Wisconsin. The initial phase of the storm arrives Saturday night. As warm air starts to nudge into southern Wisconsin, this could brin the chance for freezing rain, sleet, and snow to areas north of I-94. The National Weather Service has issued a Winter Weather Advisory from 7 p.m. Saturday through 10 a.m. Sunday in Dodge, Washington, Ozaukee, Fond du Lac, and Sheboygan Counties for a few inches of snow and up to a tenth of an inch of ice.

Dodge, Fond du Lac, and Sheboygan counties are under a Winter Weather Advisory from 7 p.m Saturday through 10 p.m. Sunday due to an extended period of sleet, freezing rain, and snow that can cause more significant travel issues. The exact precipitation type will be determined by how much warm air can move into lower levels of the atmosphere. A thicker layer of warmer air will lead to more freezing rain which is the worst case scenario for ice accretion. A thinner layer of warmer air will lead to more sleet which is preferred over freezing rain. Either way, both will make for difficult travel during this time. Most areas along and south of I-94 will have little to no impact at all.

Phase two of the storm arrives late Sunday morning into early Sunday evening with the potential for rain and thunderstorms. The track of the low pressure has trended further north, which means a warm front will sit in southeast Wisconsin, bringing the potential for a few strong storms that could produce gusty winds and large hail.

Temperatures during the day will be in the 50s and windy. Colder air will start to wrap around the low-pressure after 6 p.m. on Sunday, but with warmer air moving into the lower levels of the atmosphere, this could change precipitation to a mix of sleet and freezing rain, especially north of I-94.

If there is enough ice accretion mixed with strong winds, this can lead to ice building up on trees and power lines. Tree limbs can break as well as power outages if this occurs.

Phase three of the system will transition from precipitation over to snow by midnight on Monday through the day. Any area that has rain will freeze to ice on surfaces. Snow will start off heavy but will gradually shift to a fluffy snow as drier air moves in.

Even stronger winds arrive on Monday with gusts near 50 mph.

That can create areas of blowing snow, near blizzard conditions with extremely low visibility, and also cause the potential for more power outages. Travel can become very hazardous and difficult on Sunday night through Monday. Areas with higher icing can create near impossible travel.

The most widespread impacts across southeast Wisconsin will be during phase three, especially for travel. Snow totals will accumulate quickly heading into Monday morning. Snow totals look the highest with the potential for 6+ inches inland.

With a northward shift in the track of the system, this can increase the chance for heavy rain and potential for strong to severe storms, push the icing threat further north, and lower snow totals near the lake and south towards the Wisconsin-Illinois border. 

As we get closer to the event, the next step is to see whether the winter storm watch will be changed to a winter storm warning or winter weather advisory for areas. Stay tuned for updates.