The warm season is unfolding on schedule as we begin the first holiday of the summer season. After the big snowstorm that began the month, the weather’s been quiet and uneventful. The storm on May 1-2 was a record breaker–the heaviest one-day May snowfall at the National Weather Service (NWS) (19.8 inches), the biggest May snowstorm, as well as the snowiest month (26.2 inches). We will not see snow now until sometime next fall. However, that hasn’t always been the case in Upper Michigan. On rare occasions, there have been snowfalls in very late May.
One of those instances occurred in 1947. Low pressure developed over the inter-mountain west on May 26-27, moved out onto Plains the evening of the 28th and sat near Chicago on the morning of May 29.
Warm moist air drawn up by the low was producing rain and thunderstorms over portions of Illinois and southern Wisconsin. As the low lifted northeastward through the Lower Peninsula, it encountered an unseasonably cool air mass to the northwest over central Wisconsin and the eastern Upper Peninsula. Rain changed to snow over these areas and accumulated during the late afternoon into the evening.
Snow totals included 10 inches at Gay Mills in southwest Wisconsin and six inches at New London. In the U.P., Iron Mountain received an inch, while Marquette 2.1 inches on the far western fringe of the snow band. Farther east, Manistique collected 3 inches, Munising six inches with up to a foot reported at Eckerman in western Chippewa County.
This Memorial Day weekend will feature dry weather with gradual warming as a massive high-pressure area develops at all levels of the atmosphere over the Great Lakes. Highs will reach into the 70s away from the cooling influence of the Great Lakes. This pattern should hold through much, if not all of next week with even warmer temperatures likely.