Decline in aircraft traffic could degrade West Coast weather forecasting | KNKX

Decline in aircraft traffic could degrade West Coast weather forecasting

Mar 27, 2020

Sprinkles and showers are in the forecast for most of Western Washington this weekend, with temperatures hovering around 50 degrees. It’s perfect weather for gardening or maybe taking a long run or walk in your neighborhood. The skies above likely will be quieter, too.

The spread of the new coronavirus already has slowed air traffic aloft. An even more dramatic decline in commercial flight schedules is coming soon. And that could affect weather forecasting.

“Aircraft are an important observational system used for numerical weather prediction,” says KNKX weather expert Cliff Mass.

Globally, weather satellites are the number one system for observations. “That’s probably 95 percent of it,” Mass says. But he says there are many other important sources – especially over the oceans.

Aircraft, in particular wide-bodied planes, record weather data as they fly.

“This is a huge amount of information,” Mass says. “Right now it’s about the fourth-most important weather-data source that we have – much more important than weather observation at the surface even.”

That data is plugged into the large-scale computer models as a starting point for forecasts.

Because the West Coast faces a the vast Pacific Ocean – a source of much atmospheric activity – Mass says the impact here could be slightly greater than in places in the interior of the continent.

He doesn’t expect it to undermine our ability to know what’s coming too seriously, especially not now because spring weather is relatively benign. Most people won’t really notice. But he thinks about a 3-5 percent decline in skill will show up for meteorologists like him, who verify the forecasts retrospectively.

“I suspect we’ll see it,” Mass says.

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.