Widespread major heat, highly unusual for early June, will expand across most of Western U.S. in coming days (minus some coastal areas). Record breaking high temps most likely Thu and Fri, but may persist in some areas for over a week. #CAwx #NVwx #ORwx #WAwx #IDwx [1/2]

In addition to record daytime warmth in some areas, even more locations will record-breaking overnight warmth, with widespread "record high minimum" temperatures during this prolonged event, including at higher elevations. #CAwx #NVwx #ORwx #WAwx #IDwx [2/2]