For Some, Fog Ruins Rockets' Red Glare; It's Just a July Thing



How Islanders rated this year's July Fourth fireworks display all depended on their point of view - quite literally.

Viewed from afar, the front porch of a Farm Pond home or Harthaven in Oak Bluffs, they were a brilliant kaleidoscope of light and sound. Some even said the rapid-fire finale was the best in years.

But from downtown Edgartown, where the barge from which they were launched was moored just outside the harbor, the fireworks amounted mostly to large splotches of color lacking shape or form.

The spoiler: a low-lying fog bank that rolled in just minutes after the first rocket was shot.

"It was a 50-50 show. The finale was fine. It was just that one little bank of fog that unfortunately came in at the wrong time," said Edgartown fire chief Tony Bettencourt. "Depending on where you were, people saw the fireworks below and above."

The Edgartown Firemen's Association sponsors the annual show, which this year lasted half an hour and cost around $25,000.

"We lucked out, we got away with it," declared Edgartown harbor master Charles Blair. "The fog could have postponed them, and then we would have had to go through the whole set up again the next night. Any time you can shoot them off on the first night is good."

Mr. Blair said that more than 200 boats anchored for the show.

For many, the turn of the weather came as no surprise. In July the fog often comes on fast and thick. It's because the ocean is still significantly colder than the air; by August that discrepancy will diminish.

"Land surfaces respond to the summer season more quickly than water - it lags behind by about a month," said Tracy McCormick, a spokesman for the National Weather Service in Taunton.

"Because water has a higher specific heat, it takes a lot more to warm it by one degree than it takes to warm sand or pavement or grassy areas," Ms. McCormick said.

Consequently fog is much more likely to occur on the Vineyard in June and July than in the late summer.

The fog that rolled in Sunday night most likely was advection fog, said Ms. McCormick. Advection fog is created when warm, moist air flows over a cooler surface - in this case the ocean, which lately has seen temperatures in the mid sixties.

The air is cooled from below and, if the air is near saturation, moisture will condense out and form fog. In light wind conditions such as those that occurred Sunday, the fog closest to the water's surface can become particularly thick and reduce visibility to zero.

This year's fireworks show started promptly at 9 p.m. The temperatures had already dropped after hitting a daytime high in the low eighties; a light southerly wind was blowing.

In Edgartown the first bursts stood out sharply against the sky. People still walking the downtown streets hurried to the waterfront, some to watch from the docks by the Seafood Shanty and Chappaquiddick ferry landing; others went farther up North Water street.

But within minutes, for many standing in the downtown area, the view was obscured by the low fog bank. The highest shots still burst clearly into concentric circles of blue and green light that crackled as they rained down. But the lower explosions were signaled only by a deep boom and muted coloring of the fog.

At the show's conclusion, no matter how much or how little they had seen, bystanders offered a round of applause and boaters sounded their horns in appreciation. With several hours of the Fourth still to go, the crowd broke into twos and threes, each group to mark the evening's end in its own way.