Heat not normal for this time of the year

Roughly onethird of Americans are seeing midsummerlike temperatures this weekend as heat and humidity began to roast the Northeast and mid-Atlantic states Saturday, potentially setting hundreds of daily heat records. More than 38 million people were under a heat advisory Saturday afternoon.

In West Virginia and New Hampshire, public health officials urged people to look out for symptoms of heat exhaustion. In Washington, D.C., officials activated heat emergency plans, opening splash parks and cooling centers.

Elsewhere in the country, the misery set in weeks ago. In drought-parched New Mexico, the largest wildfire in the state's recorded history is burning months before peak fire season. Other blazes are driving evacuations and fears in Colorado, Arizona and Utah.

And in a sign of just how strange things could get, Denver whiplashed from 90-degree weather recently to a late-spring snowfall.

Memorial Day, the unofficial start of summer, is still a week away. But by the end of this weekend, more than half of all Americans will have experienced temperatures climbing to 90 degrees or higher from a blast of hot air that started in the Southwest, swept across the eastern third of the country, and move through New England.

Meteorologists warned that scores of heat records could be tied or broken in some 20 states.

The good news: The heat in much of the country is expected to pass relatively quickly — too quickly even to qualify in most places as an official heat wave. A strong cold front reaching from the Great Lakes into the Southwest is predicted to gradually drift south and east over the weekend, according to a Weather Service forecast issued Friday. Still, officials warned that even brief spells of intense heat carry the potential for grave danger, particularly for the most vulnerable populations.