The Ocean Prediction Center and "The Perfect Storm"
The Halloween Nor'easter of 1991 brought great destruction to the
northeast coast of the United States, created waves that were
felt as far south as Florida, the Bahamas, and even Puerto Rico,
and threatened the lives of hundreds of mariners. Dubbed "The
Perfect Storm" by National Weather Service (NWS) meteorologist
Bob Case, this remarkable weather event cost the 6-person crew of
the Andrea Gail their lives as the storm exploded around then in
late October 1991.
Every day, forecasters at the NWS Ocean Prediction Center
formerly the Marine Prediction Center, located in the
Washington suburb of Camp Springs, Maryland, prepare the weather
warnings and forecasts for the high-seas areas of the north
Pacific and north Atlantic, including those remote fishing sites
far from the New England coast visited by the Andrea Gail. These
forecasts are transmitted to mariners many ways, including marine
radiofacsimile for graphics, single-side-band and satellite
transmission of text forecasts, and voice forecasts over WWV.
Additionally, all of OPC's products are available on this web site.
With the aid of complex weather forecast models of the
atmosphere, imagery from NOAA weather satellites, and their own
experience in predicting maritime weather, OPC forecasters
focused their attention on the north Atlantic in late October
1991. Although a number of monstrous storms with waves in excess
of 50 feet occur every winter in the North Atlantic and Pacific,
this particular weather situation seemed especially ominous as
OPC forecasters anticipated three major weather features
interacting vigorously to produce ideal conditions for a life-threatening
storm. One feature was a cold front that passed
through New England and into the north Atlantic where it
developed a frontal low-pressure center southeast of the Canadian
maritime provinces. Behind this system a very large high-pressure system
intensified (to a near-record 1046 millibars)
over eastern North America, an important ingredient for
Nor'easters. Making matters even worse, Hurricane Grace was
making its way northward off the U.S. coast, pumping significant
amounts of moisture toward the frontal low-pressure center.
On October 27, OPC forecasters sounded the alarm that a major
storm was developing in the north Atlantic within the next 36 hours.
The next morning OPC forecasters referred to the developing system as a
"dangerous storm" in their broadcast to mariners. This was one
of the first times OPC forecasters used this term and reflected
the seriousness of the situation. That evening the frontal low-pressure
center, tapping the moisture and energy from the
hurricane, the high-pressure system, and the ocean itself,
intensified very, very rapidly right over the position of last
radio contact from the Andrea Gail. The storm continued to
deepen through the morning of October 30, then blocked by the
immense high to its north moved westward toward the U.S. coast,
an unusual event. The combination of wind-driven water (known as
storm surge) of 4-5 feet above normal tides, waves up to 25 feet
high some places along the coast, and the long duration of the
storm, which meant that the coastline was pounded by heavy surf
through a number of tidal cycles, led to extensive damage of
structures and beaches along the coast from North Carolina
northward to Canada.
This storm was well forecast by the OPC and other NWS forecast
offices. Nevertheless, with the support of the U.S. taxpayers OPC
has made significant progress in improving its products and
services since that time. To learn more about the OPC and how it has
changed since "The Perfect Storm", please click here.
Former Director, Ocean Prediction Center