Downpours and thunderstorms will be common across the Southwest into the middle of the week as a pair of disturbances join forces to bring a flash flood threat to the region.
An upper-atmosphere storm over the region will combine with a similar feature arriving from the Pacific Ocean to spark numerous downpours and thunderstorms into Wednesday, especially during the afternoons and evenings.
"Abundant monsoonal moisture will add fuel to the disturbances crossing the region," said Meteorologist Brian Edwards.
"Torrential downpours and flash flooding will be a major threat during the first part of this week," added Edwards.
Las Vegas, Palm Springs, Calif., Phoenix and Flagstaff, Ariz., will be among a host of other cities across the Southwest that will be at risk for flash flooding.
Although the valley floors will be at risk, it will be even higher across the mountains.
Drainage washes and ditches can turn into a raging torrent of water in a short amount of time in these situations.
Flood waters can quickly inundate some roadways as well over the next couple of days. If drivers ever encounter a water covered road, they are urged to never cross it.
The flash flood threat will move farther east on Wednesday toward the Four Corners region. Later this week, the moisture-laden air will move into the Plains, contributing to some very beneficial rainfall for the drought-stricken region.
As for the Southwest, the stormy weather will move away by the latter part of this week as a high pressure system settles into the region. This system will promote plenty of sunshine and warm afternoons as highs rebound into the 100s.
The corridor of showers and thunderstorms will move over central and western Texas and the southern Plains, where rainfall is desperately needed.
Heavy rain returning to the northern Plains will generate a renewed flood threat for the Red River.
More than 20 tornadoes were reported by the National Weather Service with hundreds of hail and wind reports Sunday afternoon through Sunday night.
Several tornadoes touched down from Oklahoma to Iowa, including near Wichita, Kan., and Oklahoma City, on Sunday.
Severe storms may erupt from Oklahoma to Wisconsin on Monday as the storm system that spawned several tornadoes across the Plains on Saturday and Sunday shifts slowly to the east.
Normal snowfall for the month of May is 13 cm (5 inches), according to Environment Canada (EC).
A slow-moving storm resulted in a week of below-normal temperatures that will likely continue into the week.
Milford, OH (eastern suburb of Cincinnati) (1982)
2.50" of rain in 30 minutes (3:30-4:00 p.m.)
Patuxent River, MD (1996)
Alberta, Canada (1992)
Snowfall of 1-2" between Edmonton and Grand Prairie.