***Unsettled weather pattern in the Eastern U.S.***
***Major heat wave continues in the Western U.S.***
A persistent trough and stationary frontal boundary near the Appalachian Mountains will keep the weather pattern unsettled across the eastern third of the country. Deep southerly flow from the Gulf of Mexico, along with weak shortwave energy aloft, will lead to the development of scattered to numerous showers and storms from Florida to New England. It will also remain humid along with highs in the 80s.
A drier airmass will be found over the north-central U.S., where northerly flow from Canada will usher in mostly clear skies and pleasant temperatures for this time of year.
For much of the Western U.S., excessive heat warnings and heat advisories remain in effect for a major heat wave that is ongoing from the Mexican border northward into the Inter-Mountain West. A big upper level high, combined with subsiding air and abundant sunshine, will allow temperatures to reach dangerously high levels. Some of the lower deserts near the Colorado River may reach 120 degrees! Triple digit heat is also expected for much of the Great Basin going into early next week.