The meteorological roller coaster ride our area has been on this month, with temperatures doing a quickstep from shorts and sandals to fleece and boots, is coming to an end.
The extreme freeze-and-thaw is behind us, experts say, and the rest of the winter is expected to be more comfortable, with plenty of snow.
"From here on, we can expect a milder winter, occasionally interrupted by a cold snap. Initially, it will be drier than average, but in time and it may take until mid February it will become more moist, and snowfall is likely to be above average for the season," says Penn State climatologist Paul Knight.
Last week, a polar vortex, a swirling mass of extremely cold air high above the North Pole, dipped in the United States, dropping temperatures like an ice ball as far south as Florida.
Since Jan. 1, the Carbon-Monroe-Schuylkill region has shivered through temperatures that plunged several degrees below zero, only to rise to springlike levels within hours.
"This is not as extraordinary as you might feel. It is just that we have had a string of relatively mild winters so these large swings have been less common lately, but in the 1980s and early 1990s, these swings were common," Knight says.
"The weather patterns are always shifting, which is what makes following and predicting the weather so fascinating. If anything, this winter's pattern is much closer to 'normal.' We are experiencing a more average, albeit somewhat colder, winter," he says.
"We've seen a back-and-forth weather pattern," says Mitchell Gaines, a meteorologist for the National Weather Service in Mount Holly, N.J.
"It's happened before: we see those quick arctic shocks and then the temperatures rebound fairly quickly. It usually happens a few times a times a year," he says.
"One factor is a ridge of high pressure over the Pacific Northwest, extended at times into Alaska. This directs cold air masses at times down into the central and eastern U.S. Those will come through in pretty quick order because of the lack of anything over the Atlantic to hold it in place," he says.
Along with the arctic-temperate swing, much of the precipitation that has fallen froze as it hit the ground, resulting in a thin but hazardous glaze on roadways.
"It is hard to say whether we'll have more frequent freezing rain events," Knight says. "There is no clear way to discern this. It's like predicting whether you will hit more than the ordinary number of traffic lights on the way to work it is quasi-random."
Although scientists have concluded our weather is changing globally, 2012 was among the 10 warmest years on record, according to the 2012 State of the Climate report released in August by the American Meteorological Society there is no direct connection between the recent cold snap and climate change, Knight says.
Gaines says that with "climate change, we have cycles that are decade-to-decade. These are more of a seasonal change. There are always these climate cycles that are changing year to year. We will have to wait to see if they are changing in the long term."
From January through December 2012, Pennsylvania was much warmer and wetter than normal, according to data compiled by the National Oceanic and Atmospheric Administration.
"Many of the events that made 2012 such an interesting year are part of the long-term trends we see in a changing and varying climate carbon levels are climbing, sea levels are rising, Arctic sea ice is melting, and our planet as a whole is becoming a warmer place," Acting NOAA Administrator Kathryn D. Sullivan, Ph.D. said in an Aug. 6 NOAA interview on the State of the Climate study.
While the climate change study looks at the big picture, and long term, most people are more interested in short range forecasts. For the rest of the week, the National Weather Service expects a daytime temperatures ranging from 47 degrees on Tuesday to a low of 33 degrees on Thursday, then back up to 38 degrees on Friday.
Thursday and Friday are expected to be mostly sunny, but Tuesday through Wednesday night are expected to bring a chance of rain and snow.