Blockbuster western storm heading inland with heavy rain, fierce winds

The record-breaking bomb cyclone that brought flooding rainfall to Northern and Central California over the weekend will shift its focus toward a much broader portion of the western United States.

The atmospheric river of moisture inundating the West Coast easily smashed daily rainfall records in San Francisco, Sacramento and many other locales across California to end the weekend. As the storm continues to slam California on Monday, some places could end up with more than a month's worth of precipitation in a single day.

The enormous storm spent most of its focus on the northern half of California on Sunday, but forecasters say Southern California will be the next to experience heavy rains and damaging winds.

Cities across the Los Angeles Basin typically record around 0.50 of an inch of rain during the month of October, and this would prove to be beneficial if it were drawn out over the course of 31 days. However, this storm could rack up those amounts in a matter of 24 hours as it sweeps through.

Prolific rainfall totals like those that have been observed in Northern California are not expected farther south, but that doesn't mean the weather won't be impactful in and around Los Angeles. Rainfall totals in the neighborhood of 0.50 of an inch across the valley floors are expected and can lead to a multitude of travel headaches.

Higher rainfall totals ranging from an inch or two are expected across the mountainous terrain of Santa Barbara, Ventura, Los Angeles, Orange and San Diego counties throughout the day on Monday. Rainfall of this magnitude can lead to localized debris flows, mudslides and rapid rises of creeks and rivers.

The Alisal fire burn scar area in Santa Barbara County will face an increased threat of flash flooding, mudslides and debris flows on Monday. The nearly 17,000 acres of recently scorched ground have very limited capacity for absorbing and retaining fallen rainwater. Soot and ash from burnt trees can quickly be swept downhill during heavy rain, creating potentially life-threatening conditions.

As a result of the high threat of mudslides and washouts in this area, Santa Barbara County officials issued an evacuation order ahead of the storm on Sunday.

While most of the moisture will be wrung out along Southern California's coastal mountain ranges on Monday, a powerful enough surge of moisture should result in some of the interior deserts picking up some light rain. Amounts in these locations will not be nearly as high as areas closer to the coast, but upwards of 0.10 to 0.25 of an inch of rainfall will be possible.

A passing shower or two is expected to reach the Las Vegas area by Monday afternoon as the storm begins to press inland. On top of the chance for wet weather, a very windy day is expected as well. Las Vegas won't be the only city dealing with strong wind gusts on Monday, as an expansive area of 40- to 60-mph gusts will sweep across Southern California, Nevada, northern Arizona, Utah, Colorado and Wyoming.

Wind gusts in some of the higher terrain within this zone could even approach an AccuWeather Local StormMax™ of 80 mph.

By Tuesday, conditions will begin to improve greatly across all of California as the storm shifts into the Intermountain West. Bursts of snowfall, perhaps with embedded thunder and lightning, may sweep through Utah, Colorado and Wyoming.

Heavy mountain snow will likely remain limited to elevations above 9,000 feet across this area on Tuesday, but as cold air filters in throughout the day, anyone with plans to head above 7,000 feet will want to watch the forecast closely as rain can switch over to snow and potentially come down quickly for a short time.

Although the main event of heavy rain and mountain snow will have concluded across the Pacific Northwest by Tuesday, another round of rain and mountain snow showers will move ashore, keeping the grey and dreary conditions in place in Seattle and Portland through midweek.

The massive bomb cyclone as seen from space Sunday afternoon. The plume of moisture aimed at California extended well over 2,000 miles over the Pacific Ocean, leading to what is known as an atmospheric river (NOAA).

The unsettled weather will continue to benefit the ongoing drought conditions across much of the West. Although it will come at the risk of flooding, there will be a lot of benefits that arise from this stormy pattern.

The heavy rain and mountain snow have effectively brought the wildfire season to an end across the Northwest and Northern California, and even though there is still a long way to go to erase the drought across the West, the heavy rain and mountain snow will continue to play a beneficial role in helping to fill depleted reservoirs, some of which reached historic lows this summer.

For the latest weather news check back on AccuWeather.com. Watch AccuWeather Network on DIRECTV, DIRECTVstream, Frontier, Spectrum, fuboTV, Philo, and Verizon Fios. AccuWeatherNOW is streaming on Roku and XUMO.