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Powerful Pacific Storm to Continue Impacting Northern California; Heavy Snow in the Appalachians and Portions of the Northeast

A strong atmospheric river will continue to impact northern California with heavy rain and life-threatening flooding through Friday. Unsettled weather is expected across much of the Northeast and Great Lakes over the next few days, including the likelihood of heavy snow in the central Appalachians and higher elevations of northeastern Pennsylvania and southern New York. Read More >

Overview of the December 5, 2021 Winter Storm

A modest area of low pressure located within an amplifying upper-level pattern tracked eastward from the Northern Plains to Lake Superior on Sunday December 5, 2021, spreading snow across the U.P. The surface low ended up tracking directly over the U.P. Such a track is often unfavorable for snow, because it means warm air being drawn north into the center of the low would change precipitation to an icy mix of sleet and freezing rain, or even just rain. However in this case the low began occluding as it reached the area, allowing enough cold air to remain in place for all of the precipitation to fall as snow.

The track of the low also meant there was southeast-wind lake effect snow for the Keweenaw Peninsula, and lake enhancement off of Lake Michigan for the south-central.

The south-central and eastern U.P. received the heaviest snow out of this storm - up to a foot in some areas.

The snow mostly fell on Sunday, and tapered off to flurries and light freezing drizzle Sunday night. The following day, cold air rushing in behind an Arctic cold front led to a brief snow squall across the area, followed by additional lake effect snow.

This system was also responsible for strong wind gusts, mostly over the water.

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Storm Total Snowfall, including lake effect snow on Monday December 6

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