Tropical Storm Rosa Spreading Into Southwest, Heavy Rains Expected
PHOENIX — October 2, 2018
After soaking northwestern Mexico with heavy rains as it neared the Baja California Peninsula, Tropical Storm Rosa is also expected to drench the U.S. Southwest.
Rosa had winds of 50 mph and was approximately 90 miles west-southwest of Punta Eugenia, Mexico. The storm is moving northeast at 12 mph.
Flash flood watches have been issued in parts of the region from Arizona to Utah; some residents have been filling sandbags in anticipation of heavy rainfall and potential flooding.
The center of Rosa, which was a hurricane until late Sunday, was expected to hit Baja California by Tuesday, bringing widespread heavy rains, which could cause potential flash flooding, mudslides, and landslides over the coming days. Rainfall of 1 to 3 inches per hour are possible in the areas of heavier rain, the U.S. National Hurricane Center said.
It's then expected to move quickly north-westward as it weakens, bringing 2 to 4 inches of rain to central and southern Arizona and 1 to 2 inches to the rest of the desert Southwest, Central Rockies and Great Basin. Isolated areas could see even more precipitation.
In southern Arizona, heavy rain flooded streets in Yuma and caused power outages in parts of the city on Monday. At least six roads in Tucson were closed due to flash flooding from overflowed washes.
The Utah National Guard was activated Monday to assist in flood mitigation efforts in Utah County.
Additionally, up to 1 inch of rain is possible in California, with the bulk of the rain arriving by late Tuesday and Wednesday.
The National Weather Service earlier announced flash flood watches through Wednesday for areas including southern Nevada, southeastern California, southwestern and central Utah, and the western two-thirds of Arizona.
Forecasts call for heavy rainfall in the watch areas, including Las Vegas, Phoenix, and Salt Lake City, with possible flooding in slot canyons and normally dry washes, and a potential for landslides and debris flows from recent wildfire burn scars.
Meanwhile, east of the Rockies, a pretty dramatic temperature gradient between two air masses has taken shape across the Central and Northeastern U.S. Some regions of the country could see dramatically different temperatures on either side of this frontal system.
National Weather Service meteorologists in Phoenix said central and northern Arizona stood to get hit with the heaviest amounts of precipitation.
Metropolitan Phoenix, where temperatures were above 100 degrees only a few days ago, had already cooled to the 80s on Monday thanks to Rosa. Omaha, Nebraska, will be stuck in the 50s — a difference of nearly 20 to 25 degrees over just 100 to 200 miles.
As the first week of October gets underway, temperatures across much of the Central and Northeast U.S. will be on the rise. Temperatures from the Plains to the Northeast will be nearly 80 degrees. It will feel more like summer than fall from Wichita, Kansas all the way up to New York. And in the northern part of the U.S., temperatures will be in the 60s and 70s.
Our climate forecast for the next one to two weeks shows that well-above-average temperatures are likely for the Eastern U.S.
The Civil Defense Agency for Baja California state said schools were closed Monday in several communities, including the state capital of Mexicali, across the border from Calexico, California; San Felipe, on the northern Sea of Cortez; and south of Ensenada, on the peninsula’s Pacific coast.
Federal authorities have declared a state of emergency for Ensenada and Mexicali. Various Mexican media outlets reported that a woman was swept away by floodwaters and drowned in the city of Caborca, Sonora, on the Sea of Cortez.
Meanwhile, Tropical Storm Sergio was strengthening in the Pacific and was forecasted to reach hurricane force, though it posed no immediate threat to land.
Sergio had winds of 70 mph and was centered about 695 miles southwest of Manzanillo, Mexico, moving west at 14 mph.