Late-summer heat wave baking West this week

The progression of this week's heat wave across the western U.S. is seen in this animated map showing warmer than average temperatures in red.

(Weather Bell)

A late-summer heat wave will be baking the West this week, with temperatures running as much as 17 degrees above normal in some places.

An upper-level high-pressure system will be moving through the region all week. This large dome of sinking air will produce temperatures near 90 in parts of the Pacific Northwest and triple-digit temps in the interior of California.

The forecast for a high pressure system causing the heat wave in the western U.S. this week is seen in yellow on this animated map created Sept. 7, 2021.

(Weather Bell)

Excessive heat warnings have been issued Tuesday for much of the deserts of Southern California, Southern Nevada and the Colorado River valley in Utah and Arizona. Heat advisories have been issued for a bulk of the California interior.

The National Weather Service forecast calls for high temperatures of 108 degrees in Las Vegas for the next two days. High temps of 104 to 107 are expected in the Sacramento and Fresno areas for the next two days.

Forecast high temperatures for Sept. 7, 2021.

(NWS/NOAA)

Forecast high temperatures for Sept. 8, 2021.

(NWS/NOAA)

The heat wave should peak Wednesday before the high pressure causing it begins to move inland, pushing the mercury up in the northern Rockies and Plains later this week.

Forecast high temperatures for Sept. 9, 2021.

(NWS/NOAA)

Forecast high temperatures for Sept. 10, 2021.

(NWS/NOAA)