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.
While Hurricane Cristobal will track east of the United States this week, it will spread rough surf along much of the Atlantic coast and will have some direct impact on Bermuda.
While the weather over much of the Atlantic and Pacific coasts will be free of rain this Labor Day weekend, a zone of unsettled weather will reach across part of the Central states.
Though Hurricane Marie will weaken through this week, it will bring dangerous waves and rip currents to Southern California.
After several days of summerlike warmth and humidity, cooler and more pleasant air will return to end the week.
The Cleveland area is facing the threat of thunderstorms later this week.
Warm weather fans in the Boston area will have something to be happy about this week, but Atlantic Ocean bathers may need to be aware of Cristobal.
Mt. Washington, NH (1856)
A total of 3 inches of snow on peak of mountain.
Georgia & South Carolina (1881)
335 died in a hurricane. The most severe damage was in Savannah and Charleston.
South Carolina (1893)
First of 3 great hurricanes that year in SC. Over 1,000 people drowned in tidal surge at Charleston.