The risk of localized flash flooding continues through the end of the week over part of the interior West.
Cities at risk for flash flooding during the random storms include Las Vegas, Phoenix, Tucson, Flagstaff, Albuquerque, Salt Lake City, Cedar City in Utah and Riverside, Calif.
According to Western Weather Expert Ken Clark, "An upper-level disturbance drifting in from the Pacific will focus an already in place flow of tropical moisture, known locally as the monsoon."
The end result will be more numerous and locally, extra-drenching showers and thunderstorms from interior California to New Mexico, northward to Utah and Colorado.
The storms will tend to favor, but not be limited to the high ground.
Isolated downpours can quickly flow downhill, causing canyons and arroyos to quickly fill with water.
The spotty downpours can also lead to debris flows in recent burn areas.
While area residents will welcome any non-destructive rainfall, a number of the storms will bring little or no rainfall, frequent lightning strikes and the risk for new wildfires.
"By the end of the week the storms will consolidate farther to the east and south over the Four Corners states as drier air invades from the north and west and the disturbance pushes inland," Clark added.
At such time the risk for flash flooding in Las Vegas and Phoenix will have ended.
Meanwhile, a stalled front will continue to bring rounds of drenching thunderstorms and the risk of flash and urban flooding to parts of the southeastern U.S. this week.
A stretch of dry weather across Germany will continue for much of the week ahead across Germany resulting in continued pleasant conditions for Oktoberfest.
A tropical wave is likely to become the Atlantic Basin's next tropical storm as it approaches or crosses the Caribbean Sea later this week.
Bouts of wet weather will frequent the northeastern United States during the last full week of September.
Typhoon Megi will threaten lives and property across Taiwan and eastern China into the middle of the week.
Flooding downpours will continue to cause problems in southern Texas into Monday night.
The final day of September will bring a rare lunar event that hasn’t occurred since March of 2014, a Black Moon.
Dakotas & Minn. (1942)
26th-28th, severe freeze with temperature of only degrees F. at Parshall, N.D.
N.E. United States (1950)
Blue sun and moon from forest fires in British Columbia.
San Diego, CA (1963)
111 degrees, highest temperature ever recorded.