Monsoonal moisture over the Southwest will lessen somewhat early this week, but downpours will persist for some, leading to more flash flooding.
Moisture has been streaming northward into the southwestern quadrant of the U.S. over the last few days, leading to widespread drenching thunderstorms each afternoon and evening.
The moisture was streaming around a strong area of high pressure which was centered over the eastern Rockies and High Plains.
This high pressure system will continue to weaken and shift eastward as a large dip in the jet stream develops over the West Coast.
As the jet stream dives southward it will send that monsoonal moisture eastward, effectively drying out parts of the Southwest.
Still, enough moisture will persist through much of the upcoming week to produce more downpours and instances of flash flooding for some.
Heavy rains occurred on Saturday over southern Yavapai County, Ariz. where forest fires had left large burn scars. 2-4 inches of rain over this region in a short time lead to debris flows and mudslides as well as flooding of Turkey Creek and the Agua Fria.
A local bridge was washed out on the Havasu Creek at Supai, Ariz. as well.
More instances of flash flooding will occur through the first half of this week a bit farther east over the Colorado Rockies, eastern Arizona, and much of New Mexico while areas farther west dry out.
Daily bouts of drenching afternoon and evening thunderstorms will be common from Denver and Boulder, Colo. through Albuquerque, N.M. and Nogales, Ariz.
Thunderstorms across this region can produce rainfall rates of 1-2 inches per hour which is more than high enough to get flash flooding to occur. Especially since moisture values have been elevated for quite a while now.
Along with the heavy rainfall, dangerous cloud to ground lightning will threaten to postpone or delay any outdoor activities.
If flash flooding is occurring or imminent, take the proper precautions if you need to to travel. Never drive through a flooded roadway because you never know how deep the water might be.
Always carry an emergency kit in your vehicle in case you become stranded.
Heed all flash flood watches and warnings and keep an eye on the AccuWeather.com Severe Weather Center.
Another round of rain is expected to move through the Carolinas on Saturday, which may lead to rises on some small streams and creeks.
A strengthening storm system will bring the threat for flooding, mudslides and severe thunderstorms to areas from Italy into the Balkans later Friday into the 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 "blob" of abnormally cold water in the North Atlantic, located near Greenland, has the potential to put enough drag on the ocean current to impact weather conditions in the years to come.
“It was by far the most intimidating natural disaster I have ever chased,” Storm Chaser and Extreme Meteorologist Reed Timmer said of the historic flooding in South Carolina.
Cool weekend weather is in store for the Northeast after rain and thunderstorms dampen the region on Friday.
New England (1804)
Extraordinary "Snow Hurricane" - snow mixed with heavy rains from Washington, D.C. on north - heavy snow in interior New England. Up to 2 feet in Green Mountains of Vermont.
A few snow flakes in Philadelphia, PA (trace). Also a trace of snow in Baltimore, MD.
Damaging hailstorms - $7.5 million loss to crops.