Two powerful forces of nature are heading for each other and, if they collide in the sky, their intense convergence could create the kind of superstorm that has never been documented in the history of meteorological recording and forecasting.
If that sounds like Hollywood, that's because there was a movie made about the only other "perfect storm" ever noted, said John La Corte, a meteorologist at the National Weather Service in State College.
Just how "super" this storm will be remains to be seen for York, where the work week could open with high winds, possible flooding and tornadoes.
The storm could also dump the season's first snows on western Pennsylvania and the higher elevations of West Virginia, John La Corte said.
What's happening: Hurricane Sandy is slowly moving up the northern coast of Cuba and into the Bahamas. Mean while, there's a separate storm, an area of low pressure called an "upper air trough," heading into the Great Lakes from the Midwest, La Corte said.
He described the impending storm as "a gigantic potpourri of everything that's bad about the weather."
The mid-latitude system, which is the "upper air trough," contains energy and the tropical system, Sandy, contains the moisture.
Some storms converge and are absorbed by each other, becoming weaker, La Corte said. But if these two marry in the atmosphere, there would be widespread bad weather, a potentially historic storm, he said.
"We can't find a time that this has happened before," he said. "If it happens, it is going to be something that has maybe not happened in the modern era of weather observation and forecasting."
If they continue on their current paths, that would happen somewhere off the coast, likely southern New England early next week, he said.
"If things panned out perfectly for you guys (in York) to get hammered by this, we're talking Monday," he said.
It's too far off to predict the speed of winds or the amount of rain, but there would likely be "high winds, severe weather like thunderstorms ... and tornadoes."
The closest comparison would be the "Perfect Storm" of 1991 in Cape Cod, on which the movie of the same title was based, he said.
"I was there...I can tell you it was pretty unbelievable," he said.
But he said the impending hybrid storm is likely to be a messier version of the 1991 storm.
Jamaica: According to the Associated Press, the unusual storm is likely to hit during a full moon when tides are near their highest, increasing coastal flooding potential.
And with some trees still leafy and the potential for snow, power outages could last to Election Day, some meteorologists fear. They say it has all the earmarks of a billion-dollar storm.
Sandy became a category 2 hurricane with sustained winds of 105 mph as it made landfall in southern Cuba early Thursday, according to the Associated Press.
On Wednesday, it hit Jamaica with 90 mph winds and heavy rain. Forecasters said the 18th named storm of the Atlantic hurricane season is expected to strengthen and could go on to threaten the Bahamas and possibly Florida.
Sandy's death toll was at least two. An elderly man was killed in Jamaica when he was crushed by a boulder that rolled onto his clapboard house, police reported. Earlier Wednesday, a woman in Haiti was swept away by a rushing river she was trying to cross, the Associated Press reported.
Forecasters at the U.S. National Hurricane Center in Miami said tropical storm conditions were possible along the southeastern Florida coast, the Upper Keys and Florida Bay by Friday morning. A tropical storm watch was in effect for the area, the center said.
- Reach Christina Kauffman at firstname.lastname@example.org.