Global Warming Could Significantly Disrupt Northwest Weather
For those harboring the guilty hope that global warming will transform Seattle into a sun lovers' paradise on par with the Côte d'Azur, meteorologist Cliff Mass has some bad news: It might actually get cloudier.
Mass and his colleagues at the University of Washington recently completed the most detailed computer simulation ever conducted of the region's future weather. Among the surprises was a big boost in cloud cover in March, April and May.
"The spring is going to be gunkier — if you believe this — under global warming," he said.
The model also predicts that the number of summer days when temperatures soar into the 90s will more than triple before the end of the century, if greenhouse-gas emissions from cars and industry continue unabated.
And the hopes of some water managers appear to be dashed by the finding that catastrophic losses of winter snowpack will not be offset by more summer thunderstorms.
"We're not going to make up the precipitation in the summer months," Mass said.
Local governments may need to rethink their water-supply projections, said Doug Howell, of King County's Department of Natural Resources and Parks. "We had been predicting that this region would get warmer and wetter."
Mass cautioned that the analysis is only a first cut using a high-resolution forecasting model to tease out geographic details about the way warming would change Northwest weather. Future studies will attempt to root out glitches and make the scenario even more accurate.
But even the trial run reveals nuances that previous global-warming forecasts were not powerful enough to see.
"It's going to warm up pretty much everywhere, but some places are going to warm up a lot more than others — and that has all kinds of implications," Mass said.
While earlier forecasts predicted significant declines in snowpack, the new analysis shows that the most intense warming will occur on the windward slopes of the Cascade and Olympic mountains, with the biggest spikes coming in the spring. By 2090, mountain temperatures could rise 10 degrees or more, with snowpacks reduced to about 20 percent of current levels.
That's a much grimmer outlook than earlier forecasts, Howell said.
But the new work also suggests Western Washington won't warm as rapidly or as much as the east side of the state. By 2050, temperatures in the Puget Sound region will rise about 2 degrees, while some parts of the Columbia Basin could be up to 5 degrees hotter. In 2090, much of the basin will be up to 8 degrees warmer, according to the model.
"This is not good for Eastern Washington farms," Mass said.
Continue reading this story from the Seattle Times:
An even grayer Seattle from global warming?
