On October 1, 1987, a single lightning bolt exploded from the sky right over Sunset Hill, just up from Nantucket Harbor. The Boston Globe reported that the “bolt came out of nowhere,” hitting the chimney of the Jethro Coffin House, sending it clear across the street and causing severe damage to the Oldest House on the island. The heat from the strike was so intense that it melted the glass in the windows.
While Tampa, Florida is the lightning capital of the country, the storms that do hit Nantucket seem to intensify and last longer as they pass over the island. The meteorological reason for this is known as “the heat island effect.” Surrounded by cool ocean water, the warmth of the island serves as a refueling station for storms that would otherwise dissipate as they move off the mainland. Nevertheless, lightning is incredibly unpredictable, and it’s nearly impossible to pinpoint the time and place it strikes. Just ask the Boston Pops, which had to cancel their performance last August for the first time in six- teen years due to the threat of lightning.
Photographer and island resident Larry Cronin happened to be driving by when the Jethro Coffin House was struck back in 1987. “I was there before the fire department,” he says. “The house was all closed up and it appeared the moist air inside expanded rapidly, breaking joints at the frame.” Lightning burns five times hotter than the sun, over 50,000 degrees Fahrenheit, so when it hit the house, the air molecules inside expanded instantly, setting off a bomb of pressure that blew out the studs. Fire fighters contained a small fire from the strike, but the house required extensive reconstruction to “build a new frame within the old skin,” as Cronin puts it. “But it was also an opportunity for historians to learn more about the original construction of 1686.”
Dodging lightning for three hundred years seems like a miraculous feat for the Jethro Coffin House. One has to wonder about the frequency of house fires caused by thunderstorms on the island. Nantucket Fire Department chief Mark McDougall says the storms seem to come in waves. “Some years are very busy, others not so much,” says McDougall. “But when storms do hit Nantucket, we get stretched out pretty thin; we only have so many resources to fight fires.”
This was the case on August 5, 2010 when a cold front came across the sound and met a hot humid morning on Nantucket. At 12:45 p.m., lightning hit a home at 237 Polpis Road, leaving it heavily damaged, but not a total loss. Unfortunately, the same could not be said for the home in Monomoy, which was also struck by that storm. The home was completely destroyed.
A similar direct hit rocked the UMass Boston Field Station not once, but three times on August 11th last year. “People driving on Polpis Road said it was the loudest and brightest hit that they had ever seen… they almost drove off the road,” says Dr. Sarah Oktay, the Field Station’s director. “[Resident naturalist and education coordinator] Len Germinara was there when it hit, and he said that he saw the flash and heard thunder immediately, then his laptop went poof.” Although there was no fire caused, the three strikes destroyed $20,000 of equipment. “Equipment that was screwed onto the wall was blown across the room and would have drilled me if I was there,” Dr. Oktay says. When the storm passed, the team went outside to find its “mast antenna” split down the middle like Robin Hood would another arrow.
There are procedures for lightning storms. If you can hear thunder, you are close enough to get struck by lightning. As the saying goes, “When the thunder roars, go indoors.” Moments before lightning strikes, an ionized channel between the cloud and the ground forms what’s known as a “leader.” If you’re within that leader, your hair will stand on end and you are at high risk of getting struck. Retreat indoors immediately. However, even in- doors it’s still possible to get struck. Lightning can travel through telephone and electrical cords, plumbing, and even the ground itself. There’s a legend on Nantucket of a man in ‘Sconset being struck and killed inside his bed- room because he was holding on to the metal frame of his bed when a bolt hit his home.
Many more thunderstorms will light up Nantucket’s sky in the months and years to come. It’s one of the many meteorological phenomena that we scientists and curiosity seekers yearn to witness and learn from. Our only hope is that we can live to tell the story.