Meteorologists say 'Perfect Storm' not so perfect

As a meteorological event -- not very.

In the movie "The Perfect Storm," which opens this Friday, George Clooney, and fellow cast members recreate the actual events surrounding the sinking of the sword-fishing vessel Andrea Gail on October 28, 1991.

Based on the best-selling book of the same name by Sebastian Junger, the movie's web site declares that the storm was "a unique event in recorded history." It states that "three storms combined into one," heaping waves 100 feet high, creating nothing less than "an almost apocalyptic situation."

Yet real-life experts suggest the 1991 storm may be a victim of Hollywood hype. While the storm was undeniably very powerful- and dangerous to any ship venturing offshore- all the meteorologists interviewed agreed that the storm was far from being "stronger than any in recorded history," as the web site states.

"Bottom line: the 'perfect' storm was strong, but there were plenty of stronger events on record," says meteorology professor Clifford Mass of the University of Washington in Seattle.

Junger tells Inside Science News Service that while he did not write either the movie screenplay or the web site storm descriptions, he believes the impact on the New England coast was "the worst in living memory."

A freelance journalist and author, Junger coined the phrase "the perfect storm" after a conversation with Bob Case, the 30-year veteran meteorologist who was deputy meteorologist-in-charge of the National Weather Service's Boston, Mass., forecast office at the time of the storm. Case says that while he does not recall specifically talking to Junger among the thousands of calls he fielded over the years, he likely meant that three weather ingredients had come together to create a "perfect situation." However, this is true for any major storm.

"The various meteorological events…had to occur simultaneously in the right location," Case says. However, he adds that a "perfect" situation does not mean it is unique or even exceptionally rare.

The "three storms," he said, were in fact a large high-pressure system over Canada, a low-pressure system traveling along a slow-moving cold front, and the tropical moisture from Hurricane Grace, which was dissipating at the time.

Case describes the situation as follows. The high-pressure system, originating in northern Canada, provided a large pool of cold air. The edge of this cold air-the cold front- pushed off the New England coast on Oct. 27. A weak low-pressure system was moving along the front.

The cold air behind the front and warm air ahead of it caused a strong temperature contrast to form over a relatively small area. Such a sharp temperature change caused the low to rapidly intensify. The result was what meteorologists call an "extra-tropical cyclone."

Off the East Coast, extra-tropical cyclones are called "Nor'easters," since the wind blows strongly from the northeast along the Eastern Seaboard.

A third ingredient, Case says, was the addition of lots of moisture from Hurricane Grace, which had gotten caught up into the Nor'easter's large circulation. By Oct. 31, the Nor'easter had stalled and even began moving backward (toward the west). While this is somewhat unusual, it is by no means unique and three days after the Andrea Gail had sunk.

Ocean buoy monitors recorded wind gusts to 75 mph and wave heights of 39 feet, and while higher waves were surely possible, 100-foot waves seem unlikely. However, Junger emphasized that this storm was primarily an ocean storm, causing unusually large waves far offshore. "I looked for records of larger waves, but couldn't find any," Junger says.

Junger stresses the importance of wave height. "Since wave height is so terribly significant for both a vessel at sea, as well as an exposed coastline, it's possibly a better measure of intensity than, say, wind speed or damage costs," he says.

Yet the storm was far from being the strongest ever, says Mass, adding "that honor goes to the 1962 Columbus Day Storm."

Close behind the 1962 Columbus Day Storm was the March 1993 "Superstorm," which affected an exceptionally large part of the United States, setting records for snowfall, cold temperatures and low pressure up and down the East Coast.

In 1991, strong winds and rough seas occurred on top of a monthly high tide brought about by the full moon, exacerbating the damage and flooding, Mass says.

While Case takes minor issue with Junger's explanation of the storm, he nevertheless praises Junger's overall effort. In researching the book, he said, Junger tackles topics as diverse as meteorology, oceanography, shipbuilding, the New England fishing culture, and Coast Guard search and rescue techniques. "I take my hat off to him," Case says.

So while "The Perfect Storm" may turn out to be a perfect summer movie, as an accurate portrayal of a real weather event, meteorologists say it isn't quite so perfect.