By Meteorologist Garrett Marino
From one extreme to the other.
A strong dichotomous temperature pattern has developed across the country this week, which will conclude on Sunday with the coldest temperatures for cities Philadelphia and New York likely since 1994 (near 0), and for Boston since possibly 2004 or 1957 (-7).
Meanwhile, record high temperatures for the entire first quarter of the year were set over the past few days in the Seattle area, and Los Angeles reached the mid-90s. Warmth from El Niño enhanced the western temperatures. The warmth has been concentrated there due to a combination of atmospheric factors that include simultaneous strong warming in the stratosphere and a retraction of the Pacific jet stream. When warmth gets concentrated out west, a wave response occurs that sends arctic air plunging east.
Across the North Country, temperatures will reach -10 Saturday morning and fall slowly through the day, reaching -20 at sunset and -25 by Sunday morning. Wind chills will remain in the -35 to -60 range until midday Sunday, and can cause frostbite in under ten minutes.
Unlike the past two winters’ polar vortex events that were oriented toward the Midwest and moderated some before they reached the east coast, this week’s expanse of the western warmth will allow the polar vortex to head straight from the Hudson Bay on Thursday to the Northeast on Sunday morning.
Temperatures in the past two winters reached the lower single digits in Philadelphia and New York, but never to zero. I currently am forecasting a minimum of 1 in Philadelphia Sunday morning and -1 in New York City. Strong winds will send wind chills to about -25 there.
Across the North Country, temperatures will reach -10 Saturday morning and fall slowly through the day, reaching -20 at sunset and -25 by Sunday morning. Wind chills will remain in the -35 to -60 range until midday Sunday, and can cause frostbite in under ten minutes. By Monday, temperatures will quickly rebound into the +20s.
Why won’t the cold last?
The Pacific-based El Niño and weather pattern across the Atlantic both do not support more than ephemeral cold. Some of the western warmth will reach the Adirondack North Country in the coming 6-to-10 day window.
Winter isn’t over yet.
Tropical thunderstorm activity appears to be aligning in a favorable position to change the jet stream again and give more anomalous cold late February into early March.
Garrett Marino is an MIT-trained meteorologist who recently relocated to live full-time in the Adirondack Mountains. Garrett provides statistics and observations from his lakeside meteorological observatory at Camp Thundersnow on Upper Saranac Lake, where he maintains a weather station.