The nation’s weather

Weather Underground Forecast for Thursday, June 16, 2016

Active weather will affect the eastern third of the country on Thursday, while extreme heat continues across the Plains.

A wave of low pressure will transition east southeastward over the Midwest. A warm frontal boundary associated with this system will ignite strong to severe thunderstorms across the Ohio Valley, the Appalachians and the Mid-Atlantic. Severe thunderstorms will be possible in eastern Ohio, eastern Kentucky, northeast Tennessee, western North Carolina, western Virginia, West Virginia, western Maryland and southwest Pennsylvania. These thunderstorms will be capable of producing large hail, dangerous straight line winds and isolated tornadoes. Prolonged heavy rain will bring threats of flash flooding to Pennsylvania, northern West Virginia, Virginia and Maryland. Showers and thunderstorms will also develop in the Deep South and the Southeast.

Just to the west, temperatures will spike 10 to 15 degrees above normal from the central and southern Plains to the Mississippi Valley. Scattered showers and isolated thunderstorms will be possible in the southern Plains and the lower Mississippi Valley.

Meanwhile, a cool weather pattern will linger over the Pacific Northwest and parts of northern California. An onshore flow from the Pacific will bring rain and high elevation snow to the Northwest. High temperatures will return to the triple digits across most of the Desert Southwest on Thursday as high pressure starts to expand over the region.

Temperatures in the Lower 48 states Wednesday have ranged from a morning low of 27 degrees at Redmond, Ore. to a high of 104 degrees at Salina, Kan.