The high pressure system that kept Texas murderously hot is expanding to Utah, threatening to bring the worst heat of the year so far.

Salt Lake City has yet to break 100 degrees in 1998, although Monday's high reached 99.Tuesday's high should be slightly cooler, edging up to 95 degrees or 96 degrees, says William J. Alder, meteorologist in charge of the National Weather Service forecast office on North Temple.

But Wednesday the blast furnace turns on, and it continues burning through the end of the week.

"The big high that's been sitting over Texas is moving westward," Alder said. "It's just a big, fat high aloft, a lot of warm air."

Salt Lake City probably will roast later in the week with highs between 100 degrees and 103 degrees, possibly up to 104 degrees. In St. George - where the high was 104 degrees Monday - the temperature later in the week could reach 106 degrees to 110 degrees.

Still, Utah's heat won't be as damaging as the variety that has been killing residents of Dallas. "It basically doesn't have the humidity, of course," Alder said.

Utah's air is dry, and that makes the heat more bearable. Salt Lake's relative humidity hovers around 15 percent or 20 percent, while in Dallas it is more like 50 percent or 60 percent.

Meanwhile, Utah Power shut off the power to two Sandy neighborhoods Monday afternoon to prevent worse outages caused by heavy use of air conditioners.

Also, the Utah Department of Environmental Quality issued a health warning, saying ozone Tuesday could reach dangerous concentrations. The elderly, children and people with existing heart or respiratory ailments should reduce physical exertion and outdoor activities.