The possibility of celestial fireworks joining the manmade shows can’t be ruled out for the Northland’s Fourth of July, the National Weather Service’s lead forecaster in Duluth said.
“I would say there’s an increased chance for some form of precipitation, maybe even an isolated thunderstorm, going into the fireworks period, crossing sometime in that 7-to-midnight time frame,” Jonathan Wolfe said on Monday.
The Fourth will be the start of a four-day weekend for many, and Wolfe said the Northland is generally in for a good run of summer weather — but with the possibility of storms developing just about every day.
“Overall, it’s a pretty inclement weather pattern, meaning you’ll get daytime heating, which will cause some afternoon thunderstorms most days,” he said.
After reaching the 80s on Tuesday and Wednesday in the Duluth area, temperatures should moderate to the 70s for the four-day weekend Wolfe said. That’s normal for this time of the year — highs in the mid-70s and lows in the 50s.
Similar conditions are expected in the Chequamegon-Nicolet National Forest, where thousands of people have assembled for the July 1-7 Rainbow Gathering. “Most likely they’re going to be dry,” Wolfe said. “Maybe a scattered shower here and there.”
Extreme weather conditions are unlikely anywhere in the area through Sunday, Wolfe said, although there’s always a slight chance for flooding if a series of storms track over the same spot.
But the region has known violent weather on Independence Day. Twenty years ago, on July 4, 1999, the Boundary Waters Blowdown damaged an estimated 400,000 acres of forest. The storm was a “derecho” — characterized by strong straight-line winds.
Remarkably similar atmospheric conditions occurred on Sunday morning, Wolfe said on Monday.
“The one thing that saved us yesterday was that we had a really stable boundary layer, which means basically the area near the surface was much cooler than the air up above a couple hundred feet,” he said. “It was a really eerie feeling. You could hear a roar, but the trees didn’t move a whole lot. … But right off the surface it was about 85 miles per hour. So we kind of dodged a bullet.”
For this Fourth of July, Wolfe’s advice is simply to be aware of the weather.
“The only thing I think I would do on the afternoon of the Fourth is check the forecast for that evening, just because the pattern is kind of transient,” he said. “And keep the weather in the back of your mind, because thunderstorms — even a small one — can be dangerous.”