The Perseid meteor shower peaks locally late tonight and before dawn tomorrow, with dozens of shooting stars expected to zoom across the sky every hour. But you may miss the show.

A forecast of partly to mostly cloudy skies for much of the region during the zenith could mean curtains for the annual event. On a good night, nothing fancier than a dark sky, lounge chair or sleeping bag and bug spray are needed to view the Perseid (pronounced PER-see-id) meteor shower, which appears to burst out of the sky between Cassiopeia and Perseus, the constellation for which it was named.

Just lie on your back in the darkest place with the widest view you can find and look up in any direction, astronomers say.

Because viewing is so simple and the best hours for it occur after midnight in the middle of the week, few planetariums or astronomy clubs are organizing public events for the spectacle. Many county and state parks are closed after dark, but a few will be open for the shower.

Observatory Park in Great Falls opens at dusk tonight. Point Lookout State Park in Scotland, at the tip of rural Southern Maryland, and Blackwater Falls State Park in Davis, W.Va., will be open for viewing.

The shower's official peak worldwide occurs at 7 a.m. Eastern time. However, the sun is scheduled to rise locally a little after 6 a.m. tomorrow, so the best viewing times are between midnight and dawn.

Chunks of rock from space occasionally reach the Earth's surface if they are large enough, but the particles that make up the Perseid shower are considered too small to make it through the atmosphere and hit anybody before burning up.

The mid-August shower is one of the most "dependable" annual meteor events on the astronomical calendar, said Rob McKinney, 46, of Kingstowne, president of the Northern Virginia Astronomy Club. The Geminid meteor shower in December is the other consistently strong event.

However, the Perseid is believed to be the most popular meteor shower because lying in the snow before dawn in December is a lot to ask of even the most zealous stargazers.

Around this time every year, astronomers say, the Earth passes through the densest part of Comet Swift-Tuttle's dust trail. Comet debris the size of a grain of sand or a small pebble slams into the Earth's atmosphere at 37 miles per second. The resulting air friction creates white-hot columns as the particles vaporize. These brief blazes of light are the shooting stars.

"This is not fireworks stuff," said McKinney, referring to the limited color palette of the display. "But it's the next best thing as far as what nature can provide."

The 1,000-member Northern Virginia Astronomy Club is hosting a private event tonight to watch the shower at C.M. Crockett State Park near Warrenton, McKinney said. It is not open to the public because of prior agreements the club made with park officials.

McKinney said 80 to 100 people attend the club's regular public events, during which amateur astronomers set up telescopes to offer viewers "a tapestry of stars above us [and] things that whirl and mash about." He expects "nobody to a couple dozen" members to show up for the meteor shower, given the forecast and the timing of the event.

Hopefully, it won't be lights out.

A Perseid meteor streaks across the sky in this 30-second time-exposure photograph taken in Palm Beach Gardens, Fla., in August 2002.