The NOAA stated that cooler ocean surface temperatures due to La Niña lead to a wet north and a drier south in the Golden State.
Fires are tearing through a dry Southern California, but rainy conditions have led to a wetter-than-usual winter in the state’s northern half.
As of Jan. 7, much of the Central Valley was “abnormally dry” and southern California ranged from moderate to extreme drought,
according to the U.S. Drought Monitor.
This disparity is known as a “precipitation dipole,” meaning one part of a region experiences more rain than the other.
“The average annual precipitation statewide is typically higher across northern CA than southern CA,” the National Oceanic and Atmospheric Administration (NOAA) told The Epoch Times via email. “However, this winter that difference has been on the extreme end so far.”
The NOAA stated that cooler ocean surface temperatures due to La Niña lead to a wet north and a drier south in the Golden State. The opposite occurs when El Niño conditions reverse that dipole.
In the first week of January, many parts of the state north of Santa Cruz received above-average rainfall. San Francisco received 10.36 inches, which is 110 percent of historic averages for the same time period, according to
data from the NOAA.
Around the Bay Area, major cities received between 5 and 10 inches of rainfall, NOAA data shows. Further north in the forested regions of Mendocino, Trinity, and Shasta, many areas saw between 20 and 40 inches of rain.
“While we have had several rounds of rain here in the Bay Area, southern California is still waiting on their first significant rainfall of the season,” the National Weather Service
wrote on social media platform X. “With Santa Ana winds, fire weather conditions will spike next week in LA and Ventura Counties.”
Throughout December 2024, some cities along the coast
reported surf warnings and flooded streets.
In contrast, all of Southern California has been relatively dry, recording around 1 inch or less of rain in the last three months.
Downtown Los Angeles has only
recorded 0.06 inches of rain since July 2024, though it normally receives several inches of rain during those months.
However,
data from the Los Angeles Almanac shows the area typically experiences a wet year or two followed by a few drier years, with 14.25 inches being the average.
While this season has seen a precipitation imbalance, water supply remains average or above average among 15 of the 17 major reservoirs in the state. Folsom and Millerton currently sit slightly below their historic averages, according to
data from the Department of Water Resources.
This is due to northern California rain and snow feeding most major reservoirs, which hold much of the water residents use.
According to the Jan. 2 Phillips Station snow
survey in the northern Sierra Nevada mountain range, state water officials recorded a snow depth of 24 inches. The water content of the snowpack is 91 percent of the average for this time of year.
“The forecast window is dry,” Andy Reising, manager of snow surveys and the water supply forecasting unit of the Department of Water Resources, said during the survey. “Most of the storms that are predicted are going to be north of California for the next two weeks.”
Northern California is expected to remain dry in the coming week.
“Temperatures remain warmer than seasonal averages, but recent rainfall should mitigate fire weather concerns,” the National Weather Service wrote in a Jan. 8
post on X.
It added that the rising temperatures are due to “strong high pressure along western North America.” A similar weather pattern was seen in January 1962, when the Bay Area experienced “record breaking warmth,” the agency
wrote.
Southern California is expected to continue getting dry and windy conditions,
according to the weather service.
