The boundary touched off some severe thunderstorms as it tracked south into warm, moist air over the state on Wednesday. The National Weather Service said more thunderstorm activity was possible as the front stalls and retreats northward on Thursday.

Triple-digit temperatures were still possible, but the high pressure ridge causing the intense heat is expected to shift east of Oklahoma by late in the weekend, forecasters said.

On Wednesday, clouds and rain held temperatures down slightly in northern, central and eastern Oklahoma.

Daytime highs ranged from 91 degrees in McAlester to a blistering 106 degrees in Lawton in southwest Oklahoma. Other triple-digit readings included 105 degrees in Hobart; 104 degrees in Altus and Frederick and 102 degrees in Clinton, according to the weather service.

The mercury peaked at 94 degrees in Bartlesville, Guthrie and Oklahoma City and reached 98 degrees in Tulsa.

An excessive heat warning remains in effect for Tulsa County through Friday and a heat advisory is in effect for 23 counties in eastern Oklahoma.

Skies are expected to be partly cloudy on Thursday as a slight chance of storms lingers, mainly for the Oklahoma Panhandle and eastern sections. Temperatures should reach the 90s and low 100s for highs and dip into the 60s and 70s for lows, forecasters said.

Clear to partly cloudy conditions are expected on Friday and generally clear skies should be the

Partly cloudy conditions and a slight chance of rain for the Panhandle and eastern Oklahoma are in Sunday's forecast and eastern Oklahoma may see rain on Monday.

Temperatures should reach the 90s both days before falling into the 60s and 70s both nights.