Friday, November 15, 2013

What made the Halloween nor'easter of '91 the perfect storm?

While these conditions are rare, this was not a one-time occurrence. The storm's iconic name and its popularity in film and literature have greatly helped make this storm stand out the most, but according to Kottlowski, storms from such conditions have occurred since then.
Satellite image of the Perfect Storm. Photo courtesy of Wikimedia Commons.
"It's rare for a tropical and a non-tropical system to join," he said. "But these conditions are favored this time of year. Late October to early November southern Atlantic waters are still warm enough for a tropical system, but cold air is already coming down from Canada. It's the right time for these systems to meet."
The Gale of 1878, for example, was created with similar conditions. In late October a tropical system moved out of the Keys northward along the East Coast, bringing 4.5 inches of rain to Cape Hatteras, N.C. By the time the storm reached Philadelphia, it met with a cold air system. The result was hurricane-force winds on Oct. 23 in the city and its surrounding areas, up to 72 mph. Estimates gauge that from 500-700 buildings were destroyed.
Superstorm Sandy was another similar storm, since it was part tropical and part nor'easter.

No comments:

Post a Comment