Hotter Than A Firecracker

It's a holiday weekend heat wave. With oppressive humidity and soaring mercury, this celebration of our nation's history could make history itself -- in the weather books. CBS News Correspondent Elizabeth Kaledin reports.

Throughout much of the Southwest, temperatures are already well into the 100's, and will stay that way through the weekend. The Northeast will have it even worse, as heat coupled with humidity from Boston to Virginia will be as unhealthy as it is uncomfortable.

CBS Meteorologist Craig Allen says that the weather will be especially hard on people in the Northeast, where the normal high temperature should only be in the 80s this time of year. This weekend, it will probably hit 95 to 100.

Urban heat advisories are being posted, warning people -- particularly the elderly -- to take it easy. For many it will be difficult advice to take on the biggest holiday weekend of summer.

The culprit is a weather system known as the Bermuda High. High pressure sitting out over the Atlantic that circulates tropical air in from the Gulf states, and blocks all other systems from breaking through.

"This time the Bermuda high is very strong," Allen says, "the strongest we've seen in several summers and that means that the heat wave once is going to stick around."

So once the sizzling fireworks are just a memory, the sizzling temperatures will linger on well into next week.