After days of tropical heat, New Haven will be hit by a tropical storm this weekend.

Hurricane Earl is expected to reach Long Island and southeastern Connecticut on Friday evening, bringing a heavy downpour and winds thatcould reach more than 70 miles per hour.

University President Richard Levin said Yale has a contingency planfor hurricanes, but is rarely much affected by them. Because students almost always live either on or within walking distance of campus, theUniversity does not usually cancel classes for weather and has not done so because of a hurricane since 1978, he said.

The rain may start as early as Friday morning, but should end by Saturday, whilethe temperature in New Haven is expected to drop into the 70s.

Storms sometimes knock out the power on campus, Levin said, but Yale has back-up generators for critical functions such as science experiments and patient care at the Yale-New Haven hospital.

The City of New Haven put out a press release Thursday advising residents ofsafety precautions they can take, and at least one residential college has been in touch with students.

“Close your windows!” Barbara Munck, an administrative assistant in Davenport, wrote in an e-mail to the Davenport community.

The city press release urged citizens to replace batteries in flashlights, secure yard furniture before the storm and pay attention to the weather forecast in case ofchanges.

New England generally experiences at least one hurricane per year, mostcommonly in the late summer or early fall. Most hurricanes are weak by the time they reach the northeastern coastline, though some, includingHurricane Earl, can still achieve tropical storm status.

The worst hurricane to hit New England did so in 1938, killing between 650 and 800 people.