Parts of California and Arizona brace for two YEARS worth of rainfall this week raising the risk of flash flooding after lengthy drought

Flash flood watches have been issued across the Sonoran Desert in parts of California and Arizona, where as much as one to three inches of rain are possible through Friday.

Some parts of the area, long stricken by drought, typically see that much rainfall only over the course of two years. 

'A low pressure system off the Baja coast will continue to produce heavy rain over the Desert Southwest tonight,' the National Weather Service said in a flash bulletin on Wednesday.

'A Slight Risk of Excessive Rainfall leading to Flash Flooding is in effect over this region as a result. This system, and the associated heavy rain threat, is likely to weaken and dissipate tomorrow,' the NWS said.

Radar shows the storm moving over the Sonoran Desert on Wednesday

A forecast map shows rainfall predictions through Thursday night in the Desert Southwest

In Imperial, California, forecasts are predicting two to three inches of rainfall in the region. Imperial's average annual rainfall is typically less than 2.5 inches.

It could be the beginning of several weeks of wet weather for the region, with long-range models suggesting two to three storms marching inland from the Pacific over the next two weeks.

'The storms that will roll in every two to four days are likely to drop southward to a certain point along the Pacific coast before taking a turn inland,' said AccuWeather Senior Meteorologist Brett Anderson. 

NWS forecasters in Flagstaff, Arizona, said Wednesday that a series of stronger and colder storms will produce 'widespread rain and snow' this weekend and early next week.

'Expect some slippery roadways especially as the rain starts given the length of time we've had without rain,' said NWS forecasters in Tucson. 

Flash flood watches have been issued across the Sonoran Desert in parts of California and Arizona

It comes on the heels of fierce Santa Ana winds that have whipped Southern California this week, making travel hazardous for tractor-trailers.

Some trucks were blown by the winds. One gust hit 86 mph in northern Los Angeles County, the National Weather Service said. 

The area has suffered under a lengthy drought, with 70 percent of the Southwest characterized as in 'extreme drought'. 

Downtown Los Angeles has had only 1.95 inches of rain since the October 1 start of the 'water year,' nearly four inches below normal. 

And in Las Vegas, rain has only fallen twice over the past 273 days.