11/2/2013 7:00 AM
By Charlene M. Shupp Espenshade Special Sections Editor
GRANTVILLE, Pa. — Just over a year ago, farmers in the Mid-Atlantic were beginning to shake off the effects of Superstorm Sandy — an unusual weather pattern that was a mix of hurricane and nor’easter.
While most of Pennsylvania was spared the brunt of the damage, New Jersey and Long Island, N.Y, took major hits. In the mountains of West Virginia and Maryland, it was a rainstorm that turned into snow, dumping between 2 and 3 feet of the white stuff. Parts of Pennsylvania, Maryland and Virginia were hit with 4 to 8 inches of rain.
According to John Scala, WGAL-TV meteorologist, it was a strange storm, one that had not been seen before.
Scala spoke to crop consultants and farmers at this week’s Keystone Crops Conference at the Holiday Inn in Grantville about weather extremes and Pennsylvania’s climate.
Superstorm Sandy produced a near-record low barometric reading for a storm north of the Mason-Dixon Line, and it followed an unusual track. It was the first time in modern history that a storm took a sharp turn to the west and hit New Jersey head on.
Damage estimates from Sandy stand at $65 billion, the next largest after Hurricane Katrina, which hit the Gulf Coast in 2005, according to the National Oceanic and Atmospheric Administration.
Scala said conditions at the time of Sandy’s arrival provided the perfect recipe for a massive storm. When Sandy made landfall, it hit at high tide during a full moon cycle, maximizing coastal damage.
Showing photos of different weather events, Scala said Pennsylvania can get a wide variety of serious weather conditions. Last year, for instance, wind shear toppled several farm buildings and trees in Lancaster County.
Scala said he remembers that after Hurricane Isabelle, Amish farmers were given a dispensation to allow for mechanized corn harvest because of the volume of corn downed by the hurricane.
Hail storms can “do a number on any crop,” he said. And Pennsylvania averages about 16 tornadoes a year, although most are of the F0 category.
Scala contrasted 2012 with what has been seen in Pennsylvania this year. After a wet start in the spring, things dried out in the summer. And, until the large rain storm at the beginning of October, the state was on the verge of a serious water shortfall.
There were 12 named tropical storms this year, he said, which is about average. However, most stayed out to sea.
Wind shear and dry air in the midlevel of the atmosphere were the reasons many of those tropical storms never progressed into hurricanes, he said.
Since the October rain, the state has had an above-average accumulation of rainfall.
“You don’t typically make up those type of deficits in October,” Scala said.
Tropical systems can provide much-needed rain during the summer, but if the local area becomes overwhelmed, it can lead to major flooding.
Flooding is Pennsylvania’s leading form of weather disaster, and it can come as a one-two punch as in 2011 with Irene and Lee. Scala called that “the forgotten storm” because of how Sandy superseded it.
Looking at the frozen variety, he said the state has been in a “snow drought” with most seasons of the past decade below average.
As for 2013-14, Scala is predicting a mild start to winter. But, it is not a clear-cut prediction for Pennsylvania because there is neither El Nino nor La Nina in the Pacific to drive weather patterns. The National Weather Service has said there is an equal chance for the temperature and snow to be above, at or below normal.
“As we move into the winter, we are looking good as far as soil moisture content, but as to how much we get this winter, we are leaning to a milder, drier start,” he said.
Scala’s clue comes from the Pacific decadal oscillation. It is in a negative phase, so the milder, less snowy model will continue for the time being, favoring larger storms out in the western U.S.
Scala concluded by talking about the probablility of extreme weather. He showed a graph indicating that 90-degree heat streaks longer than 10 days are on the rise in Oklahoma.
“It’s not just a greater incidence of these heat waves, but how long they last,” he said. “This plays to the variability of weather.”
Scala said he predicts there also will be more extremes in Pennsylvania’s climate.
Most weather models across the country are indicating a warming trend, he said. That doesn’t necessarily mean more storms, but as storms collect more moisture, they could generate larger rainfalls.