UPDATED 5 P.M. SATURDAY — Hurricane Rosa made a northward turn, as expected, and will curve toward the northeast over the next 24 hours and take aim on Baja California and then Arizona. There remains some uncertainty as to whether Rosa’s center will pass directly over Phoenix, but it likely won’t make much difference what exact path the storm’s center takes.
Editor’s Note: This archived article is from Saturday. Click Here for the Latest Updates on Rosa.
Rosa packs ample precipitation well beyond the storm center, with tropical-storm force winds extending 160 miles from the center. Rainfall in North Phoenix could range anywhere from 1 inch or less to nearly 3 inches. The National Weather Service has issued a Flash Flood Watch for Monday and Tuesday. Showers are expected to arrive late Sunday. Full Details:
Moisture from hurricane Rosa still on track to spread into the area later Sunday into early next week. Heavy rain w/ some flooding expected. Flash Flood Watch is now in effect across the deserts! #azwx #cawx pic.twitter.com/65T2prc6ma
— NWS Phoenix (@NWSPhoenix) September 29, 2018
Rosa’s top sustained winds dropped from 140 mph yesterday to 105 mph this morning and held at the level into Saturday evening. That weakening was expected, as the storm moved over cooler waters. Forecasters predict Rosa will weaken to tropical storm status by early Monday.
The means wind won’t be the big problem for North Phoenix, said Andrew Deemer, a meteorologist at NWS office in Phoenix.
“We might see some isolated thunderstorms, but it’s heavy and sometimes prolonged rain that will be the concern,” Deemer told North Phoenix News. “The biggest threat will be flooding from excessive rains.” [Read More]
As of 5 p.m., Rosa was moving at 12 mph, according to the National Hurricane Center. Its forward speed is expected to increase Sunday. Here rainfall latest predictions from the NHC:
- Baja California and northwestern Sonora: 3 to 6 inches, isolated 10 inches.
- The Mogollon Rim of Arizona: 2 to 4 inches, isolated 6 inches.
- Rest of the Desert Southwest, Central Rockies, and Great Basin: 1 to 2 inches, isolated 4 inches.
“These rainfall amounts would produce life-threatening flash flooding and dangerous debris flows in the deserts, as well as landslides in mountainous terrain,” the hurricane center stated.
The Phoenix NWS office now predicts a 40 percent chance the first showers will arrive Sunday evening.