A new tropical threat has developed in recent days, and it could flood parts of the drought-stricken southwest U.S. next week.
Hurricane Rosa was spinning over the eastern Pacific Ocean as a Category 4 storm as of late Friday morning (EDT). Sustained winds were measured at 140 mph. Hurricane-force winds were extending up to 40 miles from the center which, at the time, was 30 miles southwest of the Cabo San Lucas.
Rosa is the 7th eastern Pacific hurricane this season to reach at least Category 4 status. It will likely weaken a bit this weekend as it moves into cooler waters near the central Baja coast. The latest forecast from the National Hurricane Center has Rosa tracking into the desert Southwest early next week as a Tropical Storm or Tropical Depression.
Drought has been a stark reality for people in this part of the country for the past several months. The expected rain will mostly affect the Imperial Valley in California, as well as southern Arizona including Yuma and Phoenix. The latest U. S. Drought Monitor, issued Thursday, September 27, still shows “Extreme Drought” conditions in these areas. There’s only one category that’s worse.
Remnants from tropical systems can often account for 10%-20% of annual rainfall in the Southwest, so the coming rains should be welcomed news. However, it’s going to be too much at once. Rain will be steady and heavy at times from Sunday night through Tuesday. The parched ground and soils might not be able to hold all the water, leading to possible flooding of roads and maybe any crops that have somehow survived the drought. The latest outlook from the National Weather Service office in Yuma is is 1”-2” of widespread rain with 4” in some localized spots.