Monsoonal moisture from the tropics is bringing heavy rainfall to the Phoenix area and other parts of the Southwest.
Nearly an inch of rain had fallen between noon PDT and 1 p.m. PDT in central and north-central Phoenix.
"There are slow moving bands of heavy rainfall that are tracking across the area, producing rainfall rates of more than inch per hour," AccuWeather.com Meteorologist Brian Edwards said. Not everywhere is getting hit, but if you do get under a band, it won't take long for flash flooding to occur."
As of Tuesday afternoon, several reports of flooding and water rescues were reported northwest of the Phoenix area, according to Phoenix Fire Department and Rescue officials.
Portions of I-17 north of the city were inundated by floodwater, which forced closure. Several other roadways were also closed due to flooding and there was a report of a rockslide along I-17, according to NWS spotters.
Edwards said the storms will continue into the evening hours before the weather quiets down later in the night.
"It's unusual to get rainfall rates that significant, but if it's going to happen, it will happen this time of year with the monsoonal moisture," he said.
Each year, moisture from the tropics sets in across the region.
Incredible rescue! WATCH LIVE: Aerial coverage of Phoenix metro area flooding #monsoon2014 https://t.co/eNoy8u4FoE pic.twitter.com/UkIUwMttoz— FOX 10 Phoenix (@FOX10Phoenix) August 19, 2014
"It occurs during the latter part of the summer and early fall, July to early September typically," Edwards added.