The “bomb cyclone” soaking the Pacific Northwest this weekend could dump 3 inches of rain in Oregon’s wildfire-ravaged southern forests and send Portland’s autumn foliage flying into gutters.
It’s also making up for lost time.
As of this morning, Portland is just 0.45 inches behind its standard annual rainfall through Oct. 22, says the National Weather Service’s Portland office. (UPDATE AND CORRECTION: The NWS was referring to the “water year,” which starts Oct. 1. WW regrets the error.)
That might come as a surprise, given how hot and parched the summer was—at one point, the city went 46 consecutive days without measurable rain. But a wet autumn is closing the deficit.
“Realistically, we could make it up this next week,” says NWS meteorologist John Bumgardner. “We’re not forecasting that, but it’s possible.”
The weather systems in the Pacific Ocean over the past week—called bomb cyclones because the atmospheric pressure drops so steeply—have soaked Oregon since Tuesday evening, although Portland hasn’t been nearly as drenched as Oregon’s southwest coast. Portland received 0.91 inches of rain over Oct. 21 and 22, Bumgardner says.
By now, you may have heard what about a 'bomb' off the Pacific NW coast. What the heck is that? Well, in weather lingo, a 'bomb' is used to describe a rapidly deepening storm, where the storm's pressure drops 24+ mb (millibars) within a 24 hour period. #pdxtst #orwx #wawx pic.twitter.com/QMPGgcVUs2
— NWS Portland (@NWSPortland) October 22, 2021
He isn’t expecting enough rain in PDX this weekend to cause flooding. (It’s a different story on the coast, where stormy conditions could dump 4 inches in places like Brookings.) But his office has issued a wind advisory, in part because Portland’s tree canopy is still crowded with red and gold leaves.
“If the trees still have all their leaves on them, they’re like little kites,” Bumgardner says. “Plus, we wonder if the trees had a little damage from the ice storm and from the heat this summer. They might not be as strong as normal.”
More good news for people who like wet news: Projections released today by the National Oceanic and Atmospheric Administration show the Portland area receiving at least a third more rain this winter than is typical.
Just in: U.S. #WinterOutlook --> @NOAA forecast favors drier, warmer conditions across Southern tier of U.S. & wetter, cooler conditions for parts of North.
— NOAA Communications (@NOAAComms) October 21, 2021
News release: https://t.co/4OH6UWujdK @NWS @NWSCPC #Winter pic.twitter.com/UnlvTl6rJL