Forecasting the perfect storm

NOAA imagery of "the perfect storm"

Radar, satellites and computers played a role in helping National Weather

Service forecasters predict "the perfect storm" days in advance. The October

1991 storm — one of the worst in 50 years — pummeled the east coast from

Maine to Florida and served as the basis for the book and movie "The Perfect

Storm."

At the time, new numerical weather models helped forecasters predict

extreme weather events two to four days out, said Louis Uccellini, director

of the National Oceanic and Atmospheric Administration's National Centers

for Environmental Prediction.

Since then, models have become even more accurate, have better resolution,

can run further out into the future and are capable of processing significantly

more satellite data, Uccellini said. In addition, computers are faster and

forecasters today have new tools in their arsenal, such as software that

helps them predict the height of ocean waves and the interval between waves.

"So when these storms happen again, expect [forecasters] to make better

forecasts," Uccellini said.

Bob Case, a retired NOAA meteorologist and the Boston-based forecaster

who coined the phrase "the perfect storm," said the weather models did a

"fantastic job" in helping him and other forecasters predict the storm.

"My job was enhanced and helped by the computers at the time," he said.

The data showed that the conditions were perfect for a monstrous storm in

the northern Atlantic Ocean.

Despite the data, it was difficult to convince the public of the severe

storm on the horizon because Boston was enjoying beautiful sunny weather

on that late October weekend, Case said.

Joe Sienkiewicz, a NOAA marine weather expert and a forecaster on duty

in Boston during the 1991 storm, remembers having to lay maps and other

paper documents all around him. "I had a 286 processor in front of me and

was embedded in paper," he said.

Now he has seven computer screens around him, including one that provides

Internet access. "We process a lot more data," he said.