A monster storm with a central pressure equivalent to a Category 3 hurricanehas brutalized the North Central states since Tuesday. The storm has produced adriving rain from Manitoba southward into Minnesota. West of there, it's beenmostly snow with up to 8 inches being reported in central North Dakota.The storm has been producing winds approaching hurricane force (50- to 65-mphgusts) from central Canada across the northern Plains and Midwest since lateTuesday. This has made travel through the region extremely difficult and evendangerous.
A storm of this size and power doesn't come along that often, and even mostsystems that form during winter never approach this intensity. This is truly aonce-in-a-decade weather event.
Wednesday night, the storm will start to pull away causing a noticeabledecrease in precipitation across the northern Plains and Midwest. The wind willtake longer to diminish, however. The region from the eastern Dakotas toMichigan will continue to experience wind gusts over 50 mph into the wee hoursof Thursday then things will ease up a bit.
A big storm like the one currently in progress is the atmosphere's attempt toredistribute heat energy more evenly through the atmosphere. This isaccomplished through large-scale circulations that move cold air masses southand warm air masses north. The storm center itself is always found on the eastside of large upper-air troughs. Here, warm and cold air are in closeproximity. The ensuing difference in air density (weight imbalance) is whatdrives the storm's massive circulation producing large scale areas ofprecipitation and high winds.
Story by AccuWeather.com Senior Meteorologist John Kocet.
