Minor tree and fence damage from a tree limb overcome by the weight of the slushy snow in the northwest suburbs of Minneapolis. Courtesy D. Bovitz.
For the second year in a row, some Minnesotans were greeted to accumulating snows on Halloween, as heavy precipitation spread in two waves across southern, central, and eastern Minnesota on Thursday October 31, 2024. A strengthening cyclone (area of low pressure), originating hundreds of miles to the south and southwest of Minnesota, tracked through Iowa and into Wisconsin late on Wednesday October 30 into Thursday October 31, 2024. Arriving in the region with copious moisture and with some residual warm air leftover from the
record heat just two days earlier, the system first produced a wave of heavy rain over southeastern Minnesota on Wednesday and Wednesday night, resulting in totals of over an inch in some parts of Houston and Fillmore counties. A second, blustery wave of heavy rain, heavy sleet, and heavy snow then spread across southwestern, central, and eastern Minnesota from early Thursday morning into the late afternoon, as strong winds wrapped colder air into the storm's tightening circulation. Visibility fell to under a quarter-mile at times during the heaviest bursts of snow, particularly from the New Ulm Area, to near Hutchinson, St. Cloud, and over to Hinckley. The snow also spread over most of the Twin Cities area by late morning or early afternoon.Temperatures remained above freezing through the day in most places, so the accumulations had to overcome constant melting. The snow did managed to accumulate 1-4 inches to the west, northwest, and north of the Twin Cities. The snow was about as wet as snow can be, and therefore was unusually heavy, damaging some trees, limbs, and fences, and even downing isolated power lines. The snow also stuck to some roads, leading to over 200 spin-outs and crashes, according to the Minnesota Department of Transportation. The highest snowfall totals reported to the National Weather Service were 4 to 4.5 inches, reported near Winthrop, Monticello, Plymouth, and Hinckley. This was an important precipitation event too. The southeastern half of the state, roughly from Pipestone to Moose Lake, received over a half-inch of total precipitation, and many areas received 1-2 inches. The 1.26 inches of precipitation measured at the Minneapolis-St. Paul International Airport was the largest reported on any Halloween in over 150 years of record. Though this wet system could not reverse the drought conditions that expanded dramatically in September and October, the abundant rain and snow did reduce recent precipitation deficits in southern and eastern Minnesota. Just one year earlier (in 2023), another early-season wintry weather system brought accumulating snows on Halloween to many parts of the state. The snow, however, was just about the only thing the two Halloween weather systems had in common. The 2024 Halloween weather system came out of the southwest, started with quite warm air, brought in large amounts of moisture, produced heavy rain with some slushy snow, and was more or less a warmer version of a classic "Colorado Low" winter storm. By contrast,
last year's Halloween weather system came out of the northwest, started with very cold air in place, arrived with limited moisture, produced an almost powdery accumulating snowfall with blowing and drifting, and was more or less like a classic mid-winter "Alberta Clipper" system.
Posted Nov 1, 2024
KAB
