August 13, 2008
How Stormy Was It? The Summer of ’08 May Be Historic
By Peter B Lord; Alan Dunham
The hazardous weather warning distributed by the National Weather Service yesterday morning for Rhode Island and points north sounded all too familiar this summer:
"ANOTHER ROUND OF NOTABLE THUNDERSTORMS IS EXPECTED BETWEEN 2 PM AND 8 PM THIS AFTERNOON WITH HALF INCH OR SLIGHTLY LARGER HAIL ... GUSTY
NORTHWEST WINDS TO 45 MPH ... LIGHTNING STRIKES AND BRIEF HEAVY RAINS THAT MAY PRODUCE A VERY SHORT PERIOD OF POOR DRAINAGE FLOODING IN A COUPLE OF LOCALITIES."
If it seems like this summer has been stormier than usual, that's because it has been. In New England, we've already seen tornadoes, flash floods, fatal lightning strikes and innumerable thunderstorms and rainstorms.
People have been killed by lightning in Rhode Island, Connecticut, Massachusetts and Maine this summer.
It's been an extraordinary summer for lightning in southern New England, according to Theresa Mary Fischer, communications manager for Vaisala Inc., an Arizona-based company that works to record every lightning strike in the country. It sells the data it collects to meteorologists, and to insurance companies validating claims for lightning damage.
So far this year, Rhode Island has been visited with 10,171 strikes of lightning -- three times more than last year, according to Vaisala, which uses ground-based monitors to gather its data.
In 2006, there were 8,207 lightning strikes observed in Rhode Island, Fischer said. The numbers change from year to year, so she said what has occurred so far should not be construed to foreshadow what will happen in the future.
On Monday night alone, storms took down tree limbs across Massachusetts and caused flooding in Dartmouth, Mass. Lightning ignited a garage in Fairhaven.
"We're seeing more activity this summer," confirms Alan Dunham, a meteorologist with the National Weather Service in Taunton. Dunham insists the explanation is based simply on a colder upper atmosphere that allows hot, muggy summer air to rise higher and produce more disturbances.
And while the weather service issues broad warnings about showers and stormy weather, recent storms have been relatively limited in size -- so one part of the state is getting inundated while another is enjoying beach weather.
Yesterday afternoon, for instance, while skies were clear and blue over most South County beaches, a line of black clouds passed over Westerly and brought about five minutes of rain to Watch Hill. But the rest of town remained dry.
Dunham says climate change is not being cited by the weather service as a cause of the storminess. Even Bill Burtis, communications manager at Clean Air-Cool Planet, a New Hampshire- based advocacy group working toward solutions to climate change, says he could think of no reputable scientist who would point to a brief period of weather and say it results from climate change.
"But there has clearly been an increase in the incidence of extreme precipitation -- of one inch of rain or more," said Burtis from offices in Portsmouth, N.H., yesterday while a downpour rattled outside.
"And yes, heavier precipitation is in indicator of climate change," Burtis said. "I don't think any responsible climate scientist is saying this weather is caused definitely by climate change. I'd say that. But scientists wouldn't. But we have said fairly consistently that we'll see warm weather persist into fall and weather like this [rainy] get worse as climate changes puts more water into the atmosphere.
Burtis said he's lived for a long time along the Lamprey River in New Hampshire, and he's never seen it act like it has this year. "First it was absurdly low, and now it's absurdly high."
The average number of thunderstorms in Rhode Island has been fairly stable during the last 60 years, according to Janet Fisher, a climatologist at the National Climate Data Center at Cornell University. The average in June is 3.7, in July it is 4.3 and in August, it is 3.8.
So far this month, there have already been three thunderstorms recorded in Providence. In July, only one storm was recorded. In June there were three.
But overall, rainfall ranged from slightly above normal for August, to more than 2 inches above normal in July, and slightly below normal in June.
Also, the thunderstorm data is based on observations at T.F. Green Airport and didn't include storms that struck elsewhere in Rhode Island.
Last summer was drier. There were three thunderstorms in August, but total rainfall was nearly 3 inches below average. Rainfall in July and June 2007 was also below normal.
The storms may appear to be worse than the rainfall totals indicate, simply because many have been more dramatic.
For instance, the weather service confirmed a waterspout caused widespread damage in Padanaram Harbor in Dartmouth on Monday. It estimated the waterspout was 25 yards wide and it impacted two locations on the Apponagansett River that were some two miles apart. The waterspout traveled north to south, even though it occurred during a thunderstorm that was moving to the northeast.
Seven boats were overturned and partially sunk by the waterspout and three trees were knocked down.
Last week, a Rhode Island girl was drowned by two brooks in Ashland, N.H., that merged into one raging torrent when nearly 4 inches of rain fell in less than three hours. Two other people were killed by swelling streams.
Late last month, a tornado struck 11 communities in New Hampshire and killed one woman. Meteorologists also confirmed a small tornado touched down off Barrington on July 24. No one was injured.
For the rest of this week, the forecast is generally good.
Except for possible thunderstorms on Friday.
For more information about protecting yourself from lightning, go to http://www.lightningsafety.noaa.gov/fatalities.htm.
To see a real-time map of lightning activity in the United States, go to free service by Vaisala, a company that monitors lightning strikes across the country: thunderstorm.vaisala.com/ explorer.html
"We're seeing more activity this summer."
Originally published by Peter B Lord, Journal Environment Writer.
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