As Los Angeles has slogged through the punishingly hot days of the last month or so, it might not have been easy to see, but something in the air has changed. The high pressure zone that has been persistently holed up in the North Pacific for ages, and which has kept away big, drought-busting storms for much of the last four years of California drought, has apparently scattered and disappeared, says KPCC. In fact, according to a forecaster working for the National Oceanic and Atmospheric Administration, the Ridiculously Resilient Ridge has been gone for more than a month and could stay gone for a while.
NOAA researcher Nate Mantua says that the ridge hasn't really been present since August, and that it's unlikely to return for a while because it's been replaced by "a low-pressure trough" that doesn't yet have a cool nickname. Low pressure isn't a new obstacle to winter storms; in fact, low pressure is often accompanied by an El Niño, which is likely to bring rain and lots of it this winter. "Lower pressure in the Eastern Pacific is a classic pattern you'd see with an El Niño setting up with the jet stream a little more to the south," National Weather Service meteorologist Eric Boldt says. An El Niño this winter would be a mixed blessing, bringing much-needed rain and possibly destruction along with it.
There is another wild card in all of this. While the Ridiculously Resilient Ridge appears to have vanished for the time being, its "henchman," dubbed The Blob, is still around. The Blob is a large pocket of "unusually warm water" off the coast that was thought to be caused by the Ridiculously Resilient Ridge. Now that the ridge seems to have gone away, it could take a while for The Blob to follow suit, and it's not exactly known how it might interact with the El Niño. (There's "no precedent" for their meeting.)
Still, says Boldt, "We don't really have a good idea about how that might impact us, but warmer ocean temperatures typically lead to fueling the atmosphere and kind of energizing those storms. So I don't think it's going to be a negative for us." Meaning a big El Niño might show up this winter after all.
· 'Ridiculously Resilient Ridge' retires, making room for rain [SCPR]
· Meet the Two Weather Phenomena Battling This Winter For the Future of the California Drought [Curbed LA]
· Watch the Enormous El Niño Growing in the Pacific Right Now [Curbed LA]