A moisture-rich river approaching the southern California coast is expected to trigger the first significant rainfall of the year from late Monday.
The storm – fueled by a plume of subtropical water vapor at lower and middle levels of the atmosphere – could bring 1 to 3 inches of rain to the area at least for Wednesday. Some southern areas, including the foothills of the San Gabriel Mountains, could see up to 4 inches of rain, said Oxnard National Weather Service meteorologist Richard Thompson.
The most intense rain is expected all Tuesday, increasing the chances of a bad morning and evening commuting. Meteorologists are also keeping an eye on the conditions that could cause thunderstorms across the region. If a thunderstorm occurs, it will be able to produce rainfall rates in excess of one inch per hour. Officials say these rates could cause flooding near recent combustion areas.
Rain is expected to decrease by Wednesday, but scattered rains could linger Thursday and Friday, meteorologists said.
While the northern part of the state has seen some showers scattered from a previous storm over the weekend that has largely lost southern California, that region will not see much humidity from the atmospheric river, Thompson said.
“Southern California will be the big winner of this storm,” he said.
Rain appears to be just in time to help the region rebound from disappointing total rainfall after a parched start to 2020. A high-pressure backbone that spanned the eastern Pacific Ocean for much of January and February hijacked the storms. winters that typically bathe California and the Pacific Northwest during what are usually the rainiest months in the state.
A total of 0.04 inches of rain fell in central Los Angeles last month, balancing it with February 1899 for the driest February 10 ever recorded. Downtown L.A. it also recorded its combined combined driest quarter January and February after only 0.36 inches fell in the first two months of 2020. The combined driest January and February occurred in 1912, when a mere 0.07 inches of rain fell in the center.
Meteorologists and water managers who keep an eye on rainfall hope that a wet month, a phenomenon known to meteorologists as a “miracle march”, can help sustain the total lackluster of winter rain and keep the state out of drought.
A few dry months have already put a lot of strain on the state. Almost 70% of California, including much of Los Angeles County, is considered to be in abnormally dry conditions. Just over 34% of the state, including parts of the Bay Area and much of the San Joaquin valley, is considered to be in moderate drought conditions, according to maps published last week by U.S. drought monitoring.