The western states are well and truely in the midst of the first big heatwave of 2012 thanks to an intensifying upper level ridge of high pressure currently centred over the Four Corners and extends all the way up into Canada. Death Valley peaked at 123° yesterday, setting a new yearly high for the site and US. Today may get close to 125° while the heat core nudges slightly north. It got to 113° in both Las Vegas and Phoenix yesterday and like DV, it may be hotter today with 114° possible. For cities further north, Reno and Salt Lake topped out at 100 and that number will likely be coolest of this week. Boise, ID topped an impressive 108° and while this number will be hard to beat, it may be hit again once or twice before a late week cooling trend kicks in. Reno, Salt Lake and even up towards Billings, Great Falls and Spokane may all eye 105° at least once if not twice this week.

While the heat extends all the way up the western side of the continent, temperatures and humidity is much closer to normal for July with upper 80s to around 90 extending from Denver to Atlantic City. From the DC on south, big rains are expected over the next 5-10 days as a front stalls out across the Southeast.

Tags: death valley, desert southwest, US heat, western heat wave, western us heat