'Massive heat wave' on way; Oklahomans urged to pray;
Much of U.S. will feel it by next week

"The stage is being set for a massive heat wave to develop into next week as a large area of high pressure is anticipated to circulate hot and humid air over much of the central and eastern U.S.," the National Weather Service warned. "Maximum heat index values of at least 100°F are likely across much of this area by the middle of next week, with heat index values in excess of 110°F possible over portions of these areas."

"The big story for the coming weekend will be the building heat," added Jim Keeney, a National Weather Service meteorologist. "It looks like it's going to be a long-term heat wave."

Drought in central US deepens — and widens: 'Things look like they will get worse before they get better,' Texas official says

The worst drought in decades tightened its grip on the southern Plains in the past week as triple-digit temperatures and a lack of rain scorched cattle grazing pastures and parched crops, according to a report issued by U.S. climatologists on Thursday.

Exceptional drought, the most severe category measured by climatologists, now encompassed more than 70 percent of Texas and more than 40 percent of Oklahoma.

In the throes of its third worst drought on record, Texas has been the hardest hit state. The weather forecast promised little relief, with below normal precipitation expected across the southern Plains for at least the next two weeks.