Millions under heat alerts out West, early snow expected in Colorado, Wyoming

Over 48 million Americans in the West are bracing for a dangerous heat wave that will last through the holiday weekend.

Numerous record high temperatures are possible this weekend from California to Washington. High temperatures will reach the triple digits in Los Angeles on Sunday.

The last time downtown Los Angeles reached a high temperature of 100 degrees or higher was on July 7, 2018.

Elsewhere, the weather is pretty quiet for Saturday across the country. However, during the overnight hours Saturday to the early morning hours Sunday, a front will pass through portions of Minnesota, Iowa, Wisconsin and Illinois, triggering some thunderstorms.

Some of the thunderstorms moving through the area could have gusty winds and small hail. Storms should roll through Chicago just before 7 a.m. local time on Sunday.

By Labor Day, the quick-moving system could squeeze out a few showers and thunderstorms across the Great Lakes and into the Ohio Valley.

And as summer is winding down, a low-pressure system dives southward Monday afternoon and evening, producing rain and snow for the Rockies.

Accumulating snowfall is possible in Wyoming and Colorado Monday into Tuesday. It's not out of the question to see 6 inches of snow in the highest elevations, however places like Denver and Boulder, Colorado, won't see more than a trace of slushy snow before it gets washed away by rain.

The last time Pueblo, Colorado, saw accumulating snow in September was Sept. 27, 1996, when 0.8 inches was recorded.

The earliest snowfall on record in Denver occurred on Sept. 3, 1961, when 4.2 inches was measured. On Monday, Denver's high is forecast to be 88 degrees, the next day snow is in the forecast.