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- A winter storm that will hit rivers of atmospheric moisture will hit California this weekend.
- In addition to heavy Sierra snow, it can bring flooding rainfall.
- The system could turn into a blizzard in the Plains and parts of the Midwest for the first full week of 2023.
This storm system could also cause severe weather in the south.
Here’s a look at what to expect from this storm in the West, then in the Plains and Upper Midwest.
western forecast
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Humidity from the storm is already pouring across California, where it’s raining and snowing in the high-altitude Sierras.
The main slugs of the heavy rain and mountain snow will arrive on Saturday and continue into the early hours of Sunday in California. Rainfall and gusty winds from this system could disrupt New Year’s Eve plans in parts of the state, including Los Angeles and San Diego.
With enough rainfall in California and western Nevada, at least some flooding is likely from late Saturday night through early Sunday morning.
Due to this concern, flood warnings have been posted by the National Weather Service, shown in green on the map below.
Flooding can occur in urban areas, areas with poor drainage, and some rivers, streams, and streams. Landslides and landslides can also occur in areas of steep terrain.
( detail: Why Debris Flows Are Dangerous)
Much of the storm’s rain and snow will move east into the Rocky Mountains and southwest Sunday through Sunday night. Salt Lake City, Utah and Flagstaff, Arizona are two cities where rain can turn into snowfall.
On the first day of 2023, rainfall is likely in the Las Vegas and Phoenix metropolitan areas.
Expected amount of snow and rain
This storm has a warm origin because it makes use of humid atmospheric rivers. This means that the highest areas of the Sierra Nevada receive the heaviest snowfall. Areas above 7,000 feet in elevation will get a few feet of snow, but areas below that will see less snowfall as cold air arrives and snow levels drop.
Most of California’s lowlands will get 1 to 3 inches of rain. High-altitude areas below snowy elevations can see heavy rainfall totaling 3 inches or more.
Note that California will have more storms in the first week of 2023 after this one has passed. This could further increase the threat of flooding and add a few more feet of Sierra snow.
Plains, Midwest Forecast
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Snowfall from the storm will start spreading to the front ranges of the Rocky Mountains and High Plains, possibly including Denver and Cheyenne, Wyoming, by Sunday evening.
Snow is expected to continue Monday in Colorado and Wyoming, spreading to western and northern Nebraska, South Dakota, and central and southern Minnesota. Freezing rain and a narrow band of sleet can occur around the southern side of this snowfall area from the Central Plains to the upper Mississippi Valley.
Snow and gusts from the storm could likely affect much of the Midwest, including Minneapolis-St. Louis. Paul and Sioux Falls, South Dakota, Tuesday.
The path and timing of this storm through the central states is still a bit uncertain, so this forecast for Monday and Tuesday may change in future updates.
Expected snowfall
At this time, moderate snowfall (approximately 5 inches or more) is most likely to fall from northern Nebraska and parts of South Dakota to central Minnesota, northern Wisconsin, and Michigan’s Upper Peninsula.
As mentioned earlier, the future path of the storm is not yet certain, so stay tuned for the latest snowfall information.
The Weather Company’s primary journalistic mission is to report on the latest weather news, the environment, and the importance of science to our lives.This story does not necessarily represent the position of the parent company IBM.
