Remnants of Hurricane Kay could bring a rare downpour and flood California
“[C]Confidence is growing rapidly for a significant rain event in southern California, Arizona, and possibly central California and Nevada through Saturday,” the National Weather Service wrote in a Wednesday online discussion.
The relief from heat and dryness offered by such rains would be beneficial in this exceptionally dry region. However, there is a serious risk of flooding as runoff from downpours affects the parched terrain.
“[I]It’s never a good thing to have too much rain at once, an all-too-common trait among slow-moving tropical storms,” the weather service wrote. “So the potential for flash flooding is also increasing rapidly.”
Forecasters, however, point out that there is great uncertainty about exactly how much rain is falling and where.
A Category 2 hurricane with 100 mph winds, Kay is raging in the Pacific Ocean southwest of the tip of Baja California. It is expected to move essentially parallel to the Mexican peninsula over the next few days.
The National Hurricane Center is asking Kay to strengthen slightly Wednesday before beginning to weaken Thursday as it nears a possible landfall in Mexico. Hurricane warnings were issued for the central west coast of Baja California, where the storm is expected to be closest to the coast, while tropical storm warnings were issued further south.
Parts of Baja California could see up to 15 inches of rain from Kay, along with a damaging ocean wave and hurricane-force winds. Torrential rains in Kay have already killed three people in Baja California, according to local reports.
Kay’s winds are expected to hit nearly all of Baja California, even on the Gulf of California side. Kay is a large hurricane with tropical storm force winds (39+ mph) extending up to 230 miles from its center.
Potential impacts on Southern California
Kay’s size makes it likely that the storm will, in fact, have noticeable impacts on Southern California, Arizona and Nevada, although the current Hurricane Center sees the storm begin to move away from the California coast. and its offshore islands on Friday.
By Thursday, clouds from Kay will begin to spread across the southwestern United States, helping to relieve the heat. “[T]Kay’s huge cloud shield will very effectively end the ongoing heat wave in the region,” the weather service wrote.
A few outer bands of Kay could stray into far southern California as early as Thursday, according to the San Diego Weather Service’s forecast office.
Kay’s moisture is expected to spread seriously across the region on Friday, bringing the potential for precipitation from San Diego to Phoenix, with downpours possible as far north as Las Vegas.
The Weather Service has placed a large swath of Southern California in a mild to moderate risk zone for flash flooding between Friday and Saturday morning. He warned the risk could be high if model simulations converge on several inches of rainfall.
There remains uncertainty as to exactly how much rain will fall and where, but the counterclockwise flow around the storm will direct easterly winds over much of the southwest. This directional flow means that the heaviest precipitation is likely to be concentrated along the eastern slopes of the Southern California Mountains.
“The areas most susceptible to flash flooding will be slot canyons, burn scars and urbanized areas,” the weather service wrote. “The Southern California Peninsular Ranges, being the most southwestern mountains and therefore closest to the ocean and central Kay, will experience the brunt of the associated precipitation.”
The latest precipitation projections over the weekend from the wetness of Tropical Cyclone Kay. There remains uncertainty over timing and amounts, but the greatest potential for heavier rainfall remains on the eastern slopes of the mountains. #cawx pic.twitter.com/9NLlyZCeBS
— NWS San Diego (@NWSSanDiego) September 7, 2022
Current precipitation projections suggest that areas closer to the coast, from San Diego to Los Angeles, should receive around 0.5 to 1 inch of rain. The Weather Service wrote that if the storm’s track moves closer to the coast, it “would mean more precipitation in coastal cities, especially San Diego and nearby suburbs, but could eventually spread north to as far as Los Angeles on Saturday”.
Kay’s winds and rain are also likely to have an effect on California’s wildfire situation, which has worsened in recent days. Between Friday and Labor Day, four people were killed in two separate wildfires in the state.
If Kay moves closer to the coast, more precipitation is likely in Southern California and Arizona, which will help alleviate the region’s dryness and reduce the risk of wildfires. But if Kay heads further offshore, it would reduce drought relief and an acute fire risk would persist.
Kay wouldn’t be the first tropical system to impact California, but such occurrences in the state are fairly rare. They usually come from the remnants of tropical storms and hurricanes rather than direct strikes, as would be the case with Kay.
California’s most notable encounter with a tropical system probably occurred in 1976 when Tropical Storm Kathleen, previously an over-ocean hurricane, entered south-central California from Mexico. Kathleen triggered a peak rainfall of nearly 15 inches, a state record.
“Ocotillo, California suffered catastrophic damage, with 70-80% of the town destroyed,” NASA wrote in a storm summary. “Twelve deaths have been attributed to the storm in the United States.”
No named system has ever made landfall in California, although an unnamed storm in 1939 crossed the coast around Long Beach, bringing tropical storm conditions.
The tropical Atlantic is occupied, but there is no threat of American landings
Elsewhere in the tropics, the Atlantic is bubbling with activity after a rare August with no named storms.
Danielle, a Category 1 hurricane, dancing harmlessly in the Atlantic Ocean, is expected to loop more than 600 miles northwest of the Azores islands before heading towards Spain as a post-hurricane. tropical.
Hurricane Earl, currently also a Category 1 storm, is expected to become the season’s first major hurricane, rated a Category 3 or higher, on Thursday evening. The big storm is expected to graze Bermuda, which is under a tropical storm warning due to the potential for strong winds and rough seas over the next 36 hours.
Two other systems caught the attention of forecasters from the National Hurricane Center. A tropical wave west of the Cape Verde Islands has a 60% chance of developing into a tropical depression within the next 48 hours, while a strong tropical wave moving off the African coast has a 30% chance to transform into a tropical system. in the next five days.