STATE COLLEGE — Relief from the frigid air and the Polar Vortex that has briefly brought life-threatening conditions to approximately 240 million people in the United States and southern Canada is on the way.
That big and nasty Polar Vortex will exit to the north during the second half of this week, and a far-reaching January thaw will begin, said Alex Sosnowski, an expet senior meteorologist at Accuweather.
The coldest part of the air - which caused local temperatures to dip to -4 degrees on Tuesday and 1 degree this morning - will rotate through and depart today. As this happens, temperatures will climb out of the cellar from west to east from the Plains to the East Coast.
Over most of the Central states, South and Northeast, less wind will make for less harsh, less dangerous conditions today.
By the weekend, temperatures over most areas affected by the arctic cold will reach average or above average levels for the middle of January.
Here in the Central Susquehanna Valley the daytime highs will be about 53 degrees on Saturday and 48 degrees on Sunday, Accuweaather reports this morning.
The temperature rebound will be shared with pockets of rain, ice and snow as the week progresses.
The arctic blast was given extra momentum by a southward shift of a large cold storm that most of the time hangs out near the Arctic Circle. That storm is called the Polar Vortex.
According to AccuWeather.com Senior Meteorologist Brett Anderson, “We were overdue for a large arctic outbreak of this intensity.”
On average, outbreaks as large and intense as the one that occurred early this week occur once every 10 years. The last far-reaching, bitterly cold blasts occurred in the mid-1990s, during February of 1996 and January of 1994.
According to AccuWeather.com Chief Meteorologist Elliot Abrams, “The outbreak this week managed to break the string of a lack of record lows during January that has been ongoing in the 21st century in Atlanta, Chicago, Baltimore and Philadelphia.”
This particular blast of arctic air swooped southward over the Canada Prairies to the northern Plains, then turned eastward over the Ohio Valley and interior South. The Continental Divide acted as a barricade to the dense, low-level arctic air and its gusty winds.
“For the most part, the arctic air avoided the warming effects of the Great Lakes,” Anderson said.
Because of the indirect path the air mass took relative to New England, the northeastern corner of the U.S. and neighboring Canada was spared the worst of it.
In order for New England, Quebec, New Brunswick and Nova Scotia to get super cold, super fast you need an air mass to build southward from the Hudson Bay region, avoiding the Great Lakes so doing,” Anderson added.
An example of this was the bitterly cold blast that hit the region late last week in the wake of the blizzard.
The clock will be ticking on the upcoming January thaw as well.
According to Long Range Weather Expert Paul Pastelok, “After a relatively mild middle part of January, we are likely to experience a return of arctic blasts later in the month.”