Flooding downpours closed roads and caused other problems across the Southwest over the weekend, and more heavy rain is in store.
The combination of the intense heat baking the Southwest and the presence of monsoonal moisture is once again allowing thunderstorms to develop from California to the Four Corners this afternoon.
"Much of the activity will favor the high ground through early tonight, but there can be a few exceptions," stated AccuWeather.com Expert Senior Meteorologist Alex Sosnowski.
A couple of the thunderstorms could drift over neighboring lower elevations.
Enough moisture is present that some of the thunderstorms will do more than provide a spectacular light show and briefly force those outside indoors. Torrential and slow-moving downpours easily capable of triggering flash flooding and mudslides will be produced.
This threat is greatest across the mountains and neighboring deserts across central and southern California and the higher terrain outside of Las Vegas, Nev.
Officials may be forced to close roads that become inundated with flood waters or debris. Streams and normally dry washes could turn into raging waterways.
Flood scenes that played out across the region late Saturday are sure to be repeated.
A few fire crews battling the Chihuahua Fire in San Diego County, Calif., became stranded when heavy rain from a thunderstorm flooded roads in and around the blaze Saturday afternoon. No one sustained injuries.
On a positive note, the rain did enable firefighters to get the upper hand on the blaze which was started Thursday by lightning. The Los Angeles Times reports crews expect to fully contain the 1,900-acre fire tonight.
Another thunderstorm Saturday afternoon caused water with embedded boulders to stream down Highway 38 near Big Bear City, Calif.
The danger of thunderstorms sparking flooding downpours will subside Tuesday across the Southwest as a dome of high pressure suppresses the monsoon moisture into Mexico.
That moisture may not stay absent from the Southwest the rest of this week, likely surging back northward and enhancing thunderstorm activity Friday and into next weekend.
The focus for severe storms will move into the Ohio Valley and resume over New York state on Wednesday.
So far this year California has seen 1,569 wildfires, 85 percent more than in an average year.
The Memorial Day weekend will begin cool, windy and rainy in New England and part of the mid-Atlantic.
GOES-East failed again late Tuesday. It is one of the main satellites meteorologists use for the eastern part of the United States and the tropical Atlantic.
The tornado tore through a path 17 miles long on Monday and had wind speeds as high as 200 mph.
On the two-year anniversary of the EF-5 tornado that leveled Joplin, Mo., the town has deployed assistance to Moore, Okla.
Sichuan Province China (1986)
More than 35,000 homes and 7,700 acres of crops were destroyed by a devastating hailstorm. Reports indicated that 100 people were killed and 9,000 injured. (Reports vary as to the exact date of the hailstorm.)
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.
Hallam, NE (2004)
The "Hallam" tornado touched on the ground for 2.5 miles and reached F4 status at it's peak intensity. 95% if the town of Hallan's buildings were damages or destroyed.