From an historic blizzard to record heat, extreme weather to slam U.S. this week

Forecast temperature departures from average across the U.S. on Feb. 23, showing record cold in the West, and record heat in the East. Image: Weatherbell.com

The U.S. is currently plastered with severe weather advisories, from blizzard warnings in Minnesota and Wyoming to high wind alerts across the West and Plains.

The big picture: The extreme weather on tap for the U.S. this week will feature record-breaking cold in the West along with heavy snow, facing off against record heat in the East.

  • In the battle zone between air masses, and aided by jet stream energy aloft, will be a powerful winter storm that is set to deliver the Twin Cities one of its top 5 snowstorms of all time from Tuesday through Thursday.
  • As of Tuesday morning, nearly 50 million Americans were under watches or warnings for significant accumulations of snow and ice, covering all or portions of at least 22 states.

The National Weather Service (NWS) is warning of "life-threatening" conditions during the snowstorm in the Twin Cities due to heavy snow and strong winds, with the Winter Storm Severity Index indicating "extreme" impacts.

  • This is the highest level on the scale, indicating "substantial disruptions to daily life."
  • Heavy snows will also fall across the Rockies, Plains, into the Midwest, Great Lakes and northern New England by the end of the week.
Record cold and snow

Threat level: Cold temperature records are likely to be set from the Dakotas to California, as frigid air is pulled down from Canada on the back side of the strengthening low pressure system.

  • On Wednesday and Thursday, temperature departures from average could exceed 45°F below normal across Montana, the Dakotas and into eastern Colorado.
  • Many cold temperature records are likely to be set during this period, both overnight lows and daytime highs.
  • The combination of storms rolling in off the Pacific and unusual cold may yield a rare lower-elevation snow along the West Coast, with even the hills surrounding San Francisco having a chance at some accumulation.

Between the lines: The main storm system looks to deliver a raging blizzard from the Plains to parts of the Midwest, with the Twin Cities forecast to see about 2 feet of snow fall between Tuesday and Thursday.

  • Blizzard warnings are up for parts of Minnesota due to the combination of heavy snow and strong winds.
  • Flight delays are likely to ripple outward from Minneapolis-St. Paul International Airport, which is a major Delta Airlines hub and could be forced to shut down for a time due to the heavy snow and high winds.
  • South of where the heavy snow falls, a strip of heavy icing is likely to take place, and this may be a particular problem in the Midwest and Northeast, where enough freezing rain may fall to cause power outages.
Record warmth affects the East

For many locations in the East, this week will continue the theme of a no-show winter.

Zoom in: Multiple cities, including the Boston to Washington corridor, are already on track for their top 10-warmest meteorological winter (December, January and February).

  • Temperatures in the 70s°F to about 80°F, which is 30°F to 40°F above average for this time of year, could reach D.C. and Baltimore by Thursday, with record-shattering warmth enveloping the Ohio Valley, South and Southeast as well.
  • Temperatures in the 70s*F could even make it into Pennsylvania.
  • The NWS predicts dozens of cities, from Florida to the Tennessee Valley, Ohio Valley and Mid-Atlantic will see record warm overnight temperatures, as well as record warm daytime highs on Wednesday and Thursday.
  • At the same time, cold temperature records are likely to be set from the Dakotas to California, though the East's warm milestones may end up being more numerous.

Context: In most of the Lower 48 states, winter is the fastest warming season, with extreme cold episodes moderating over time and shortening in duration, data from Climate Central, a research group, shows.

  • Warmer than average winter days are becoming more frequent.

The bottom line: In an online forecast discussion, the NWS summed up this week by saying that nearly the entire contiguous U.S. will see "some form of notable weather."

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