Downtown shook around 11:30 p.m. Sunday, as Juneau experienced the second night of what's usually a rare event in Southeast Alaska - thunder and lightning.
"I assumed it was some kind of explosion or something, it was so loud," said Mike Kelly, a systems programmer for the state who lives aboard The Radiant, his 33-foot wooden and fiberglass sailboat, with his wife, Barbara, and their cat, Masi.
The Kellys were anchored on D Float in Aurora Harbor, almost straight across from The Breakwater Inn, when they heard a series of thunderclaps for 10 to 15 minutes, followed by another burst 30 minutes later. Mike was falling asleep, but awoke to disconnect his power and electronics.
"I was certainly concerned about having a 40-foot piece of aluminum sticking over my head," he said. "But I figured there were lots of boats with masts taller than mine."
Lightning is unusual, but not unheard of in Southeast Alaska, said meteorologist Tracey Ress in the National Weather Service office in Juneau. Thunderstorms observed late Saturday and Sunday nights developed in British Columbia and Yukon Territory.
"It wasn't just Juneau that was having thunderstorms," she said.
Canadian storms were developing Monday and the conditions appear right for them to develop today as well, she said.
The lightning, accompanied by booming thunder, was observed at the airport between 11:30 p.m. Sunday and 12:30 a.m. Monday. Ress said Juneau does not track or record lightning strikes.
The lightning caught Kelly by surprise. He's lived in Juneau for seven years and has never heard thunder here.
"A lot of the boats aren't grounded to saltwater on purpose," Kelly said. "In times of lightning, you're supposed to have some sort of device, like a jumper cable which you clip to the shroud line - the wires going to the top of the mast - and then drop in the water to ground for that reason. That was one of my things on my list to do somewhere down the line."
Nearly 24 hours earlier, a lightning strike triggered an area-wide Sunday morning power outage at 2:15 a.m.
The second thunderstorm didn't knock out power, but the first one indirectly led to electricity being out for at least an hour in Juneau Monday morning, Alaska Electric Light and Power office manager Gayle Wood said.
Monday afternoon, Wood said AEL&P staff members believe that the outage early Sunday caused depletion of a battery that powered communication between Taku Inlet and the Snettisham hydroelectric station, which provides about 80 to 85 percent of Juneau's electricity.
At about 7:30 a.m. Monday, a Snettisham breaker opened, misreading a garbled communication from the Taku Inlet, Wood said. Power to most of the community was restored around 8:30 a.m. Some customers in the Mendenhall Valley weren't back up until after 9 a.m.
Wood said the battery problem might have been detected if AEL&P hadn't had to respond to a pole fire that led to a second Sunday outage.
She said the problem has been taken care of, but she is unsure what surprises the weather has in store.
Recent thunderstorms have developed because of heat inland, with bases high enough to clear the mountains as they were pushed to coastal Alaska by the current prevailing flow of weather systems, Ress said. If their bases weren't so high, the storms would have dissipated on the mountains, she said.
Late Monday afternoon, a thunderstorm cell had already rotated over Hyder in far Southeast and visible storms were again possible for the Juneau area, Ress said.
"Typically we have much cooler maritime weather," she said. That lacks the warmth and instability needed to create strong thunderstorms.
Monday's high temperature of 64 was about 20 degrees cooler than peak temperatures last week, when Juneau was in the middle of eight straight days with highs in excess of 80 for the first time since records began in 1943.
May set a record, too, as Juneau's driest.