Forecast skill has limits for predicting winter, but it's saving lives in Northern California | KNKX

Forecast skill has limits for predicting winter, but it's saving lives in Northern California

Oct 11, 2019

KNKX weather expert Cliff Mass says it’s going to get a bit warmer over the weekend and he’s confident that “real rain” won’t set in until Tuesday evening.

But it’s harder to answer the question many people in Washington are wondering about right now: with record early snowfall in our passes and the unseasonably cold start to fall, should we expect a cold, snowy winter too?

EXPECT ‘NORMAL’ WINTER — MAYBE

“Quite frankly the skill is not very substantial,” Mass said about our long-term forecasts. This year, the prediction is for a "neutral" year — no El Niño and no La Niña to tip the scales in any particular direction, based on sea surface temperatures in the tropical Pacific. So, despite the foot of snow that fell at Stevens Pass this Tuesday, Mass says he’s not expecting a hard winter. All bets are off.

“There’s no reason to expect the temperatures won't be anything but normal — precipitation normal," he said. "So that's what we expect for this winter."

But there are areas where forecasting skill is saving lives this week, Mass says. The precise predictions of Diablo winds that can cause and stoke wildfires in Northern California were used to strategically shut off power there. Mass calls this a “triumph.”

PREDICTING WINDS, AVERTING FIRE

“That prevented any of these faulty lines from starting fires,” Mass said. “We had very severe winds. Winds gusting to 70-80 mph in the hills. These are the kind of winds that would have started fires — would have caused electoral system to fail and spark. And with the power outage we didn't have any fires.

“So it was extraordinary," he said. "We avoided the just disastrous events of the last two years." 

Events like the devastating wine country fires in 2017 and the Camp Fire that leveled the town of Paradise last year.

That doesn’t mean forecasting is a panacea for wildfire. Thursday night, wildfires exploded across Los Angeles, where Santa Ana winds stoke blazes that in many ways resemble those attributed to Diablo winds. But Mass says there’s a key difference in Southern California. A densely packed population and people who aren’t always careful.

“There's a lot of human initiated fires — just a tremendous number of people down there,” Mass said. “And so you know shutting off the power doesn't necessarily help.”

He says the forecasts were excellent. Authorities knew the fire risk was there.

“I mean the population has to be warned you know that there has to be very, very careful not to start fires and people have to be ready to evacuate if they're in vulnerable areas.” Mass said.  

CLIFF’S FORECAST:

Friday: morning frost in places, cold and crisp temperatures yielding to “just a perfect fall day.” Sunny with highs in the upper 50s – low 60s.

Saturday:  dry with increasing cloudiness, temperatures around 60, showers on the coast, some sprinkles around Puget Sound.

Sunday:  partly cloudy, morning sprinkles in places. Highs in the upper 50s. “So you know really a pretty boring weekend.”

Monday-Tuesday: Dry Monday. Tuesday night, as a strong front moves in, the first “real rain” for days starts to arrive. Wednesday should be wet.

Weather with Cliff Mass airs at 9:02 a.m. Friday, right after BirdNote, and twice on Friday afternoons during All Things Considered. The feature is hosted by KNKX environment reporter Bellamy Pailthorp. Cliff Mass is a University of Washington professor of atmospheric sciences, a renowned Seattle weather prognosticator, and a popular weather blogger. You can also subscribe to podcasts of Weather with Cliff Mass shows, via iTunes or Google Play.