In the past year, Pennsylvania has experienced unusual weather patterns. Historic flooding and record-breaking precipitation last spring and fall were followed by a relatively warm, dry winter and spring.
"Springtime and fall (of 2011), we saw lots of rain," said Aaron Tyburski, a meteorologist for the National Weather Service. "Two tropical systems came right up the East Coast, which brought all of the flooding in the second half of the year."
This year, so far, has been just the opposite, with an early and warm spring.
"So far in April, we've been pretty close to normal, temperature-wise. Following that very warm March, we've kind of leveled off in April, though temperatures are still above average," he said.
Tyburski won't go so far as to
(From Page A-1)
say that global warming alone is responsible for the unusual weather over the past few years, but he will concede that Pennsylvania's climate is shifting.
"Global warming and climate change are tough subjects to discuss because of all the factors that can cause a change in temperature," he said.
Tyburski explained that the weather service updates climate information every 30 years. The last data set began in 1980 and ended in 2010. Looking at that data, he said temperatures appear to be on the rise. However, Tyburski would not hazard a guess as to why the shift was occurring.
"It could just be the typical cycles of weather itself. Weather is never uniform," Tyburski said.
"We can't draw conclusions yet because we need a longer data set," he added.
He explained that it is difficult to draw long-term conclusions about Pennsylvania's climate because even at sites that have a "long history" of recorded temperatures, those only have data for about a century.
Local weather record-keeping began in 1895 for Williamsport, for instance.
"When scientists start to ponder why this is happening, they get away from the data and start talking about opinions. Those opinions will be probably discussed as passionately as religion or politics," Tyburski said.