Heat blankets Midwest

Heat is expected to rise thorugh much of the country over the next few days, with high temperatures triggering heat-related warnings in come areas.

According to Weather Underground, 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.

The 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.

The National Weather Service in Cheyenne says high pressure at the mid and upper-levels of the atmosphere will remain locked in place across the southern and central plains through the next couple of days. While a few isolated showers or thunderstorms will be possible along the dryline, most areas will remain dry and hot. High temperatures on Thursday and Friday are forecast to be 10 to 15 degrees above average across much of the central and southern plains. Heat indices may reach 100 to 110 degrees for some areas, and heat advisories have been issued for much of this region.

Warm and dry weather will hold across the Cheyenne Weather Area (CWA) through Friday under southwesterly flow aloft. Little in the way of cloud cover seen with a generally dry airmass emanating from the desert southwest.

Upper high will build over the southern Rocky Mountains Saturday keeping mid level temperatures warm and the airmass capped. A eak surface front may slip southward over parts of the Nebraska Panhandle late Friday but little effect should be seen.

In the long term, Saturday through Wednesday, strong upper-level ridging is expected to yield a prolonged period of hot and dry conditions across the CWA through Sunday. A general southwesterly flow should prevail in the mid and upper levels with the majority of shortwave energy tracking to the north and west of the forecast area.

A lack of forcing/moisture would suggest little or no chance for precip through the weekend. Widespread temperatures in the 90s for highs along east of I-25. Shower and thunderstorm chances should increase by early next week as ridging flattens and weakens capping. A cold front progged to sweep across the area early Monday will likely be the focus for storm development for Sunday night through Tuesday.