Fox News Weather Center

Relief From Historic Western Heat, but Not for Long

The record heat wave going on across the West will ease across many locations by this weekend. However, the relief is only temporary as another round of extreme heat is expected by early next week.

The large bubble of hot air in place across the West will be shunted to the south as a dip in the jet stream moves into the Pacific Northwest Thursday and Friday.

As this occurs, temperatures will drop anywhere from 10-15 degrees across the West as compared to previous days.

Even Death Valley, Calif., where the temperature hasn't dropped below the 90-degree mark since June 25 will finally fall into the 80s by Friday morning.

Temperatures will first ease by Thursday across the Pacific Northwest as the dip in the jet stream moves onshore. Temperatures Thursday afternoon in Pendleton, Ore., and Boise, Idaho, will rise into the lower 90s, a far cry from the 100s of recent days. Both cities will cool off into the upper 80s by Friday and the weekend.

It will take until Friday and more so Saturday for the slight relief to move into California, Arizona and Nevada. High temperatures will remain in the 100s on Thursday for Reno, Nev., and Sacramento, Calif., before falling into the middle 90s by Saturday, which will be more reminiscent of this time of year.

It will remain quite hot across Phoenix, Las Vegas and Death Valley right through the weekend, but temperatures will at least revert to more typical values instead of these extreme, near-record highs.

Instead of highs closer to 115 degrees for Phoenix and Las Vegas, afternoon highs on Saturday and Sunday will be around a more normal 105 degrees.

Across the Intermountain West, moisture will begin to increase in coverage late this week and this weekend as the heat wave breaks down. This will lead to elevated chances for afternoon and evening thunderstorms from Phoenix and Albuquerque through Grand Junction and Salt Lake City.

This increase in moisture could lead to locally heavy downpours, and with a very dry soil in place across the West, any downpours could lead to flash flooding across the interior West.

Arroyos and dry streams could easily turn into raging rivers from any of the afternoon thunderstorms later this week and this weekend.

For more information and to check out the latest flooding or heat-related watches or warnings, click over to the Severe Weather Center.

The relief from the extreme heat won't last all that long as meteorologists track another round of above-normal heat which is expected to expand across the West by early next week.

While temperatures aren't expected to be quite as extreme as the last few days, highs will rise toward 110 degrees Monday and Tuesday for Phoenix and Las Vegas while Reno and Sacramento approach the 100-degree mark.

Unlike the last heat wave which was confined to the western half of the country, this next round of heat early next week could stretch all the way through the East and Gulf Coast regions.