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.
Following a wet and warm end to the week, the weekend will turn out dry and cool in Washington, D.C.
Joaquin continues its journey across the northern Atlantic toward Europe, where it is expected to impact Spain and Portugal this weekend.
Winter will kick off with mild weather in the Northeast and mid-Atlantic as an intensifying El Nino influences the weather pattern across the country.
A fall-like weekend is in store for the Northeast, after rain and thunderstorms will dampen the region on Friday.
Another round of rain is expected to move through the Carolinas on Saturday, which may lead to rises on some small streams and creeks.
Oho will hit parts of British Columbia and Alaska with drenching rain, gusty winds and pounding seas before the week comes to an end.
Des Maines, IA (2000)
A barometer reading of 30.73" - a new October record.
Philadelphia, PA (1703)
"...fall of snow,...northwest wind blows very hard." Isaac Norris quoted in Watson Annal Phila.
Chicago, IL (1871)
Great Chicago Fire: 250 lost, $196 million loss -- severe drought prepared scene - a strong S/SW wind blew fire across the city.