By Kevin Coughlin
Twice last month, brief but powerful storms slammed Greater Morristown, toppling trees and shutting down power to thousands of residents.
Were these examples of the increasingly violent storms that some forecasters say we can expect as global temperatures rise?
And would burying power lines minimize extended outages that have become a way of life in our area since Tropical Storm Irene in 2011?
Experts aren’t ready to go out on a limb on either issue.
WHAT HIT US?
The National Weather Service says a “squall line” of strong winds was responsible for the July 14 damage, which included several parked cars battered by falling tree branches around 3:30 pm.
Police urged residents to avoid travel, a Verizon 5K race was postponed, and the National Park Service closed Fort Nonsense in Morristown for more than two weeks.
A gust of 53 mph was recorded at Morristown Airport. Technically, that’s 5 mph shy of the minimum for a “severe thunderstorm.” But the NWS also factors in damage reports when making that designation, said Lead Forecaster Sarah Johnson at the Mt. Holly weather station.
On July 30, a large cluster of thunderstorms — not quite a squall line — produced a “downburst” just before 3 pm, Johnson said.
The term refers to air that sinks quickly during a storm.
“When it hits the ground, it has no place to go but out,” the meteorologist explained. Downbursts generally cover wider areas, causing less intense havoc, than microbursts, she said.
No strong wind gusts were recorded this time, although there was heavy rainfall, just like on July 14.
Some 20,000 customers immediately lost power on July 30, when lightning knocked out a 230,000-volt transmission line that supplies a Morristown substation, said Scott Surgeoner of Jersey Central Power & Light.
Four utility poles snapped on Western Avenue, which was closed to traffic in Morristown and Morris Township. Eighty percent of JCP&L’s customers in Morris Plains lost electricity.
Power was restored throughout Greater Morristown by 6 pm the next day, Sunday, according to JCP&L.
Aftermath of July 30 storm, slideshow photos by MG contributors
Residents expressed surprise at the intensity of these back-to-back storms; Morristown Mayor Tim Dougherty wondered if a tornado had struck last weekend. Are we witnessing the fury of global warming?
“It is impossible to link severe events like this directly to something like climate change,” said Rutgers Professor David Robinson, New Jersey’s state climatologist. “Fact is, it is summer, which is the season for severe storms in New Jersey. July has been an active month to be sure!”
Last month was the state’s hottest July in 30 years, with Newark’s average temperature measuring 2.5 degrees above normal, said Johnson of the National Weather Service.
So far in 2016, the Mt. Holly weather station has issued 167 severe thunderstorm warnings for 15 New Jersey counties and parts of Pennsylvania, Delaware and Maryland. Last year was even busier, with 209 warnings over the same span. July typically spawns the most thunderstorms, she said.
Getting walloped twice last month was an “unfortunate coincidence” for Greater Morristown –“it is hit-or-miss”–and not necessarily evidence of wider cataclysms, Johnson said.
“It’s hard to relate climate change to a single event or a single season. It happens on a global scale, over decades,” she said.
More aftermath of July 14 storm, slideshow photos by Kevin Coughlin
The National Weather Service issued a severe thunderstorm warning for this area 23 minutes ahead of the July 14 storm. But the warning was eight minutes late on July 30, Johnson said.
“It’s harder to warn for winds than for hail,” she said. “Hail shows up on radar pretty well.”
Mayor Dougherty praised last weekend’s “stellar” response by police, firefighters, public works employees and JCP&L crews. He plans internal meetings to brace for more.
“My worry is this pattern of extremely fast moving, strong storms that seem to hit us very hard,” the Mayor said.
CAN YOU DIG IT?
Nobody can deny the environmental and aesthetic benefits of trees, which provide life-giving oxygen, cooling shade and natural beauty.
Yet Irene, the Halloween “Frankenstorm” of 2011, Hurricane Sandy, and July’s one-two punch have cast trees in a different light: As lumbering agents of darkness, raining destruction on homes and power lines.
Although Morristown has been diligent about removing weak trees, “you can’t storm-proof everything,” said Rich Wolowicz, the town arborist.
Sidewalks and streets that are part-and-parcel of urban areas hamper development of strong roots, he said.
“Once the soil gets saturated, and you get wind and rain, trees are going to uproot. If it’s dry and there are heavy winds, they’re going to snap,” Wolowicz said.
So why not move vulnerable power lines underground?
“It can cost seven to 10 times more” than above-ground lines, answered JCP&L’s Surgeoner.
Underground lines are subject to flooding–a problem during Sandy–as well as accidents from construction digs, and even gnawing by subterranean creatures.
“In addition, the repairs to underground construction typically take longer to repair than overhead,” Surgeoner said.
“It takes longer to identify the problem, and then the digging, repair, and returning the area that was unearthed to make repairs, is more time-consuming and expensive than typical overhead construction. Ultimately, customers of an electric utility bear the costs for any type of construction and for the utility to supply service.”
Nearly all new residential and commercial developments in the U.S. install underground power lines, according to a 2013 study by the Edison Electric Institute, an industry organization. However, those facilities invariably are served by above-ground transmission lines.
While weather is responsible for 54 percent of outages, according to 11 years of data analyzed for the study, fewer than 10 percent of customers polled for that study were willing to double their electric bills to pay the “realistic costs” of burying their power lines.
Citing downtown Morristown’s history of exploding manholes and fires in its underground network, Morris Plains Mayor Frank Druetzler said he’s “not that crazy” about the idea of burying his borough’s electric lines.
“The cost would be phenomenal,” he said. “About 20 years ago, we looked at burying them underground at Speedwell Avenue. It would have been $1 million just for a block.”