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.
The 99th running of the Indianapolis 500 is set to take place on Sunday afternoon, but showers and thunderstorms may make an unwelcome appearance.
After a cooler and dry start to the holiday weekend, a surge of warmth will greet most Memorial Day cookouts and activities in the mid-Atlantic.
Memorial Day marks the unofficial start to summer, but the summer warmth set to dominate the Northeast next week will not be here to stay.
Dry weather will be the rule in Charlotte, North Carolina, this weekend, the site of this week's NASCAR race.
New Brunswick, NJ (1804)
Tornado destroyed 2 barns, 1 hotel and 3 houses. "The damage done in this village cannot be less than $1,500 or $2,000." New York Evening Post, June 5, 1904.
Waterville, ME (1832)
Kennebec Flood discharged 140,000 cubic feet of water per second -- high stage not equalled until 1901, and not exceeded until 1936.
Lewistown, ME (1911)
101 degrees -- hottest ever in New England during May.