When will record cold relinquish its grip on western US?
The unseasonably cold air that has settled over the western United States will be in no hurry to leave into the end of February.
A seesaw temperature pattern has set up across the country, with record-challenging warmth in the East and temperatures well below late February normals on the opposite coast.
“The persistent dip in the jet stream will continue for the remainder of the week, bringing unseasonably cold conditions to the West,” AccuWeather Meteorologist Brett Rathbun said.
The number of cities that will challenge record lows will dwindle as the week progresses, when compared to Monday night. It will remain cold enough for residents to bundle up in the mornings, crank up the heat and take precautions against frozen pipes.

“Temperatures will average 6 to 10 degrees Fahrenheit below normal across the Southwest and along the West Coast, and between 10 and 20 degrees below normal across the northern Rockies,” Rathbun said.
The Interstate 5 corridor from Seattle and Portland, Oregon, to Redding, Sacramento and just west of Bakersfield, California, can expect overnight lows in the 20s and 30s on a nightly basis into the weekend.
“Parts of California will deal with frost on a daily basis, which can kill plants sensitive to cold and damage outdoor vegetation,” Rathbun said.
Preventative measures may need to be taken, such as bringing plants indoors overnight or placing a protective covering over them.
AccuWeather Senior Agricultural Meteorologist Dale Mohler expects the heartier crops, such as thick-rind oranges, not to sustain widespread damage during the cold snap.
Mohler stated that non-citrus crops over the Central Valley will be most susceptible to damage in the cold conditions.
Any Pacific storm that plows through the cold air will provide opportunities for snow, even in some lower elevations.
Enough snow fell in Portland on Tuesday night to slow traffic and cause spin-outs on the slick roads, and another few inches of snow fell in the same area on Wednesday night.
A second system will drop in late this week with spotty snow from the Sierra Nevada to the central and southern Rockies.

This storm could even bring a few rain showers to coastal Southern California.
Yet another storm will plow into the Pacific Northwest over the weekend.

The calendar flip from February to March may not signal the return of warmth that some residents may be hoping for.
We expect the chilly pattern to persist in the West, especially the Northwest, into the beginning of March, according to AccuWeather Senior Meteorologist Jack Boston.
Boston anticipates the pattern to produce more opportunities for rain and mountain snow for the Pacific states and Southwest, including California.
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