The heatwave in the West will expand into the Plains then into the East through Mid-August.
Early this week, the heat will expand into the Pacific Northwest, impacting eastern areas of Oregon and Washington with temperatures in the 90s and low 100s F.
Later this week through the weekend, the heat will expand into the Plains and Midwest where once again we will see temperatures in the 90s and low 100s F. For this area, the heat will last through August 14th before a cold front will bring some relief. The humidity will be high as well making it feel like it’s well into the 100s.
Next week, the heat will expand into the eastern part of the country. Many areas of the East have been in a rainy weather pattern and now the heat is coming which combined with the humidity will mean heat index values in the low 100s. Temperatures for the the most part will be in the 90s, but some places could hit 100 degrees. The heat will last through August 15th before a cold front brings change to cooler weather, and also sets the stage for tropical problems.