A potentially historic snowstorm is set to pummel southern Wisconsin on Saturday, potentially breaking records for snow in late April and early May, according to forecasters.
The standard for April snowstorms for Madison is the 12.9 inches that fell April 9 (and 0.8 inches more on April 13) in 1973.
After that date on the calendar, Madison's biggest total is 10.2 inches on April 16, 1921.
After that date on the calendar, Madison's record totals are 7.3 inches on April 23, 1910, 7.8 inches on April 30, 1994, 4.8 inches on May 3, 1935, and 3 inches on May 10, 1990.
Saturday's storm could top all of those post-April 16 record totals.
The National Weather Service has issued a winter storm watch for Saturday for southern Wisconsin, running from 10 a.m. to 10 p.m. for the Madison area.
Widespread snow totals of 5 to 7 inches are expected, with a very narrow band of higher amounts possible, accompanied by winds gusting as high as 35 miles per hour, meaning “travel could be very difficult,” the Weather Service said.
The snow is forecast to start in the Madison area and points west during the mid-morning hours and continue through the early evening, while the time frame will be late morning or early afternoon through the late evening.
Snowfall rates during the afternoon will likely reach 1 inch per hour, with warm pavement temperatures resulting in a rapid slushy accumulation that will be difficult to travel in, the Weather Service said, adding that temperatures falling below freezing Saturday night will cause any standing water and slush to freeze.
The higher snow accumulations will occur on grassy and elevated surfaces, with sunshine and temperatures in the 40s on Sunday causing a lot of the snow to melt, especially on roads and sidewalks.
Friday’s beautiful weather will provide no hint of the cruel cold and snow coming Saturday, with sunny skies, a high near 60 and northwest winds at 10 to 20 mph, gusting as high as 35 mph in Madison.
After an overnight low around 38, there’s a slight chance of rain before 8 a.m. Saturday, rain and snow from 8 a.m. through 11 a.m., and snow after 11 a.m. mainly ending by 10 p.m., with 3 to 5 inches during the day and 1 to 3 inches at night in Madison, the Weather Service said.
The temperature should fall to around 33 by 3 p.m. and fall to 26 Saturday night, with east winds gusting to 25 mph Saturday and north winds gusting to 30 mph Saturday night before easing.
27 Storm Track meteorologist Branden Borremans forecasts 5 to 7 inches for most of the Madison area, with 3 to 5 inches to the north and far southwest.
Elsewhere across the state, Racine could see 2 to 6 inches of snow, Wisconsin Dells 2 to 4 inches, La Crosse 3 to 5 inches, and Chippewa Falls little to no snow as the storm hammers southern Wisconsin, the Weather Service said.
The snow will melt away in Madison on Sunday with a high of 46 under sunny skies, with north winds at 5 to 10 mph turning out of the southeast in the afternoon.
Any precipitation next week will be rain, the Weather Service said, with a 60 percent chance Sunday night and possible totals of a tenth to a quarter of an inch, 50 percent chance Monday, 30 percent Tuesday after 1 p.m., 50 percent Tuesday night and Wednesday, 30 percent Wednesday night, and 50 percent Thursday.
Skies over Madison should be cloudy Monday, mostly cloudy Tuesday, cloudy Wednesday, and mostly cloudy Thursday, with highs near 51, 54, 54 and 60, and lows Sunday night through Wednesday night around 36, 38, 41 and 43.
Borremans forecasts light rain Sunday night; scattered light rain showers Monday, especially in the morning; rain developing overnight Tuesday into Wednesday; scattered showers Wednesday; and showers possible Thursday.
Borremans said skies over Madison should be sunny Friday, cloudy Saturday, mostly to partly sunny Sunday, mostly cloudy Monday, partly sunny Tuesday, cloudy Wednesday, mostly cloudy Thursday, and partly sunny next Friday, with highs near 59, 38, 47, 51, 55, 55, 60 and 56, and overnight lows around 36, 25, 36, 37, 42, 43, 40 and 36.
Thursday’s high in Madison was 70 at 12:46 p.m., 9 degrees above the normal high and 15 degrees below the record high of 85 for April 25, set in 1990.
Thursday’s low in Madison was 42 at 4:56 a.m., 3 degrees above the normal low and 21 degrees above the record low of 21 for April 25, set in 1972.
Officially, 0.08 inches of precipitation was recorded at the Dane County Regional Airport on Thursday, boosting Madison’s April precipitation total (rain plus snow converted to liquid) to 2.58 inches, 0.24 inches below normal. The meteorological spring (March through May) total rose to 3.5 inches, 1.52 inches below normal. The 2019 total rose to 9 inches, 1.3 inches above normal.
Madison’s record precipitation for April 25 is 1.94 inches in 2009.
With no snow on Thursday, Madison’s April total stayed at 1.7 inches, 0.7 inches below normal. The meteorological spring total stayed at 4.5 inches, 4.9 inches below normal. For the snow season (since July 1), Madison has received 56 inches, 5.5 inches above normal.
Madison’s record snowfall for April 25 is 0.3 inches in 1910.