A powerful spring storm taking shape in the West is forecast to spread a swath of heavy snow from the Rockies to the Plains, and eventually across the northern Midwest into northern New England by the end of the week. At the same time, the storm may trigger several rounds of severe thunderstorms, including the threat for tornadoes, as it moves across the country.
Snowfall projection through Friday April 12 from the GFS computer model.
Click on the image to enlarge. Credit: Weatherbell.com
This storm will be notable for its broad geographic reach and multiple hazards, ranging from blizzard conditions with heavy snow and powerful winds, to severe thunderstorms containing large hail, damaging winds, and potentially tornadoes. While spring snowstorms are not unusual in the Rockies and Great Plains, this storm is expected to tap into an unseasonably cold air mass that is seeping south from Canada, which will help energize the storm and allow it to produce major snowfall amounts of 2 feet or more in some spots, such as the Colorado Rockies and northwest Nebraska.
As meteorologists at the National Weather Service’s Weather Prediction Center said in an online forecast discussion on Monday, “Unusually cold air currently just north of the Canadian border is poised and ready to surge southward along the eastern slopes of the Rockies as High pressure builds and moves southward. This potent combination will produce a widespread snowstorm/blizzard…”
The storm will be near the Four Corners region this evening before moving into northeast Colorado on Tuesday. Rain and snow is forecast to break out across Colorado and Nebraska on Monday, along with the threat of severe thunderstorms in the eastern parts of the two states as cold air clashes with warmer, more humid air to the east.
National Weather Service graphic depicted the likely impacts of the storm in the Denver metro area and eastern Colorado.
The National Weather Service is forecasting 6 to 12 inches of wind-driven snow across the Denver metro area, with greater amounts in higher elevation areas, including Boulder. A blizzard warning is in effect just outside the city of Denver due to the expected combination of high winds and heavy snowfall, which could reduce visibility to near zero at times. The weather across Colorado on Monday is about as changeable as it can get, with showers and thunderstorms breaking out, then changing to a wintry mix, followed by heavy snow as temperatures tumble through the 30s.
April can often be a snowy month in Denver, and while this storm is expected to wallop parts of the state, it is not forecast to rank in the top 5 largest April snowstorms on record in Denver.
The snowiest April in the “Mile High City” occurred in 1933, when 33.8 inches fell, and the largest snowstorm on record for the month occurred in 1885, when 23 inches fell in less than 24 hours.
Heavier snow is expected to accumulate in the mountains of Colorado, and a blizzard warning was issued for parts of northwestern Colorado from 6 PM Monday evening through midnight Tuesday night. More than a foot of snow is expected to fall there, accompanied by 60 mph winds that could lower visibilities to 0.25 miles or less, and cause 3 foot tall snow drifts to pile up.
The storm will spread heavy snow to northwestern Nebraska, which could aid in drought recovery, as the state is suffering from some of the most severe drought conditions of any state in the lower 48. As of April 2, 94 percent of Nebraska was experiencing extreme to exceptional drought conditions, the two worst categories on the U.S. Drought Monitor. Northwestern Nebraska could pick up close to a foot of snow, while even more may pile up through Wednesday in parts of neighboring South Dakota and Wyoming, which are also suffering from long-running precipitation deficits. The snow, along with some sleet and freezing rain, will be accompanied by very strong winds, which will make for treacherous travel conditions.
From there, the storm is predicted to bring accumulating snow to Minnesota and Wisconsin, while sparking severe thunderstorms across the Plains into the Middle Mississippi Valley states through midweek.
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