MORONGO BASIN — A high-pressure system is chasing El Niño storms away from Southern California, shrinking the region’s chances for a winter wet enough to ease the drought.
The same system has been blocking Pacific rainstorms from California for several years, National Weather Service meteorologist Chris Stachelski said.
“It moves around slightly, but overall it’s been there most of the winter. It’s generally the same pattern we’ve seen in the last few winters, which is why we’re in such a severe drought,” Stachelski said Tuesday.
“If it stays where it is, you’re not going to get a lot of storms coming in.”
Some rain is getting through. Tuesday brought a small storm through the Morongo Basin, leaving trace amounts of precipitation in most Morongo Basin communities.
“The high is not totally blocking the storms. It’s blocking the storm track from setting up for a prolonged period to bring storms from the Pacific into Southern California and Southern Nevada,” meteorolgist John Adair explained. “It’s directing the storms into Northern California and Southern Oregon.”
Even Tuesday’s storm, while light in Southern California, sent more water to the north.
The high-pressure system is not impenatrable.
It moves around a little bit. Storms can come in and temporarily knock it down and come across,” Adair said.
The system also broke down for about a week in early January, when two storms dropped more than 2 inches in some places in the Hi-Desert, but there’s no guarantee for when it will go away again.
“The bottom line is it doesn’t matter if El Niño is there or not; if that high stays there, there’s not much of a way for storms to come in from the Pacific,” Stachelski said.
High-pressure systems more commonly set up in a certain area for a few weeks, not a few years, and meteorologists are not sure why this one is so persistent.
“It’s not really understood exactly why it’s sitting there,” Stachelski said. Possible reasons range from warmer ocean temperatures not related to El Niño to large-scale factors in the atmosphere.
The system has flipped El Niño expectations. Late last year, national forecasters explained that El Niño weather patterns typically create dryer winters in Northern California and the Pacific Northwest and wetter winters in the southern strip of the United States.
“What’s happening is the storms that Southern California would be getting are going to the north instead,” Stachelski said.
The storms are helping California’s dry spell by recharging northern reservoirs, but it won’t be nearly enough to end the drought.
“For the areas that can’t tap into or depend on getting that water from Northern California, there’s going to be problems,” the meteorologist said.
If Southern California stays dry, it also won’t help the wildfire risk.
“The outlook was never for El Niño to stop the drought,” he pointed out. “It would ease it, but at this point it’s not even easing it.”
There have been pockets of moisture in January, including parts of the Morongo Basin.
“The western part of the Morongo Basin — Yucca Valley, Morongo Valley — didn’t do bad with rain, but there were other areas that did not get as much,” Stachelski said.
January’s biggest storm so far, hitting Jan. 6 and 7, dropped more than 2 inches of precipitation in Morongo Valley and Yucca Valley, but less than a half-inch on Twentynine Palms and Wonder Valley.
All hope isn’t lost for storms to push through in the next couple of months.
The National Weather Service notes that typically, effects from El Niño in the Great Basin and Mojave Desert are more notable in February through April.
Seasonal outlooks for January through March still show a higher than normal likelihood of above-average rainfall in the West.
A three-month outlook from the National Oceanic and Atmospheric Administration released Sunday finds above-normal precipitation is still probable in Southern California, including the Mojave Desert.
“Confidence for precipitaton is still above normal largely becase we’re in El Niño, and there’s still hope the pressure could break,” Stachelski said.
“Typically in El Niño there is an increase in February, March and early April; it tends to get wetter,” he added. “There is still hope it could do that. It’s too early to write it off yet.”