Summer weather outlook: What to expect in south-central Pennsylvania in 2023
We're about a week away from the unofficial start of summer, and many of you are wondering what kind of summer we can expect.
As part of our Summer Weather Outlook Week, chief meteorologist Joe Calhoun has the forecast.
"We've been looking at some things over the last, oh, probably month to six weeks. The last three years, which is a little unusual, we've been in what we've been telling you is a La Nina pattern. What does that mean? Well, it means cooler than average waters along the equatorial Pacific.
"But we're now going into what we call an El Nino period. That means warmer waters down here.
"Well, how does that change things? It really has a big influence on our winter forecast. But what it does do is strengthens the southern jet stream, we call the sub-tropical jet stream, so it does look wetter down south, and I think some of that moisture with cool air over Canada could be drawn up into the Susquehanna Valley.
"We could use the rain right now, and I do think that's going to be part of the summer, this coming summer, very warm weather and probably pretty dry across the Rockies and parts of the Pacific Northwest. They need the rain in parts of the plains.
"So, here's what I'm thinking: Temperature-wise, normal to probably slightly above average temperatures as we go through this summer.
"Now, precipitation near normal. We've been a little dry, but I do think we're going to start to pick up some more moisture as we go through the next several weeks.
"So, cooler and wetter, I think will be in the first half of the summer. It gets hotter and a little drier as I think the Bermuda high starts to build toward the end of this summer.
"We do know that El Nino is building. We just don't know how strong it's going to be. There are some indications it could be very strong. That could really impact our winter forecast. We've got a couple of months for that, though.
"Less prolonged heat waves. Each of the last four years – the years, not just June, July and August, but the entire warm season – we've had 30 or more 90-degree days. Average is 23. I think we're going to be below that 30, maybe into the 20s, because I think we're going to get some wet and stormy spells, so that'll kind of knock the heat down. It'll build and then come right back down.
"The tropics, though, also could be affected by El Nino and that would mean they be a little less active. We'll see. We'll have that outlook coming up the first week of June."