2018 going out with a roar across southern Wisconsin. See what precipitation will fall and when

December 31, 2018

2018 will be going out with a roar across southern Wisconsin, as a storm system delivers rain, freezing rain and snow, with several inches of snow possible north of Madison, according to forecasters.

Freezing rain is predicted to begin spreading into southern Wisconsin on Monday morning, with southeast Wisconsin changing over to all rain by mid-day, and the area of freezing rain quickly lifting north and changing to snow as it reaches areas north of Madison to Fond du Lac, the National Weather Service said.

The area from Sheboygan southwest through Portage and Lone Rock could see a wintry mix for much of the day, while snow accumulations of 3 to 5 inches are possible from Wisconsin Dells to Fond du Lac and Sheboygan counties.

A period of freezing drizzle is possible as the precipitation winds down Monday night.

“This is a very complicated weather forecast with temperatures hovering very close to threshold levels, and also changing throughout the day,” the Weather Service warned. “Those planning to travel today into tonight should stay up to date on what will be a very dynamic forecast.”

Officially, much of southern Wisconsin is under a winter weather advisory starting at 9 a.m., with the advisory ending at noon for the counties of Lafayette, Green, Rock, Walworth, and Jefferson, and 3 a.m. Tuesday for Sheboygan, Columbia, Dodge, Iowa and Dane counties.

For the Madison area, snow accumulations of 1 to 3 inches and ice accumulations of up to a tenth of an inch are expected, with the precipitation changing from freezing rain to snow in the later afternoon and early evening.

The Weather Service said that in Madison on Monday, rain, snow, and freezing rain are likely before 11 a.m., then rain between 11 a.m. and 3 p.m., then rain and snow after 3 p.m., with patchy fog after 9 a.m., a high near 35 and southeast winds at 5 to 10 miles per hour turning out of the north in the afternoon. Little or no ice accumulation is expected, and daytime snow accumulation of less than an inch is possible.

Overnight, look for drizzle, snow, and freezing drizzle before 2 a.m., then a chance of snow and freezing drizzle between 2 a.m. and 5 a.m., a low around 24, and patchy fog before 9 p.m. Little or no ice accumulation expected and new snow accumulation of less than a half-inch is possible.

There’s just a chance for flurries before noon on New Year’s Day, and no chances for precipitation listed through the weekend while temperatures warm back over normal.

Skies over Madison should be mostly cloudy on New Year’s Day, sunny Wednesday and Thursday, mostly sunny Friday and Saturday, and partly sunny Sunday, with highs near 24, 25, 32, 37, 41 and 37, and lows Tuesday night through Saturday night around 13, 17, 22, 27 and 27.

27 Storm Track meteorologist Branden Borremans forecasts a freezing rain-rain mix developing Monday morning, changing to a rain-snow mix in the afternoon and then all snow by the evening ending overnight, with up to an inch of snow falling south of Madison, 1 to 3 inches in the Madison area, and 3 to 5 inches north of Madison.

Borremans said quiet weather will follow the storm system, with no chance for precipitation until a little light snow is possible later in the day next Monday.

Borremans said skies over Madison should be cloudy on New Year’s Eve, mostly cloudy on New Year’s Day, mostly sunny on Wednesday, partly sunny Thursday and Friday, mostly sunny Saturday, partly sunny Sunday, and increasingly cloudy next Monday, with highs near 34, 24, 22, 29, 37, 37, 37 and 32, and overnight lows around 23, 6, 12, 21, 25, 26, 23 and 25.

Sunday’s high in Madison was 32 at 10:02 p.m., 5 degrees above the normal high and 24 degrees below the record high of 56 for Dec. 30, set in 2004.

Sunday’s low in Madison was 19 at 8:12 a.m., 7 degrees above the normal low and 35 degrees above the record low of 16 below for Dec. 30, set in 1887.

No precipitation was recorded at the Dane County Regional Airport on Sunday, leaving Madison’s December and meteorological winter (December through February) precipitation total (rain plus snow converted to liquid) at 1.63 inches, 0.07 inches below normal. For the year, Madison has received 50.17 inches of precipitation, 15.73 inches above normal.

Madison’s record precipitation for Dec. 30 is 1.62 inches, set in 1884.

With no snow on Sunday, Madison’s December and meteorological winter total stayed at 2 inches, 11.1 inches below normal. For the snow season (since July 1), Madison’s total stayed at 5.4 inches, 11.8 inches below normal.

Madison’s snow depth is 1 inch.

Madison’s record snowfall for Dec. 30 is 6.1 inches, set in 1971.

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