Will Chinese surveillance balloon heading east reach Western Pennsylvania?

The Pentagon says the Chinese balloon spotted over the western U.S. is a surveillance balloon, leading to the question: Will it arrive over Western Pennsylvania?

The balloon is heading east, and there is a chance it could end up over Western Pennsylvania, the National Weather Service said Friday. Still, it’s difficult to pinpoint the balloon’s exact course.

“Our balloons that we launch usually go up in the atmosphere and drop a few hundred miles away,” National Weather Service meteorologist Colton Milcarek said. “They’re carried by the wind here at the surface and the wind that is aloft. When you get a balloon that’s aloft for a long period of time, it’s usually carried by the jet stream.

“Here, we have a pattern where the jet stream is arcing over the western U.S. and dropping down in the eastern U.S. And so, conceivably, if there’s anything in that jet stream, that would be carried sort of in our direction. Meteorologically, that supports it. But precise tracking is hard to do this far out with exactly where it’s going to go.”

Milcarek said the jet stream is strongest during the winter in the U.S. and runs from west to east.

“What we have now is what we refer to as a meridional pattern (a jet stream that’s very wavy as it crosses the U.S.),” Milcarek said. “So anything that’s carried in the atmosphere is, at least at that level, going to follow with the path of the wind. It will dip down into the eastern U.S. and eventually make its way out to sea.”

The jet stream winds are blowing at 140 mph, Milcarek said. That means, if the Chinese surveillance balloon does reach Western Pennsylvania, it will happen by Sunday.

The weather service is predicting clouds moving in over the weekend, so, even if the balloon does get here, it will most likely be difficult to see.