Bill Jennings: Continuance of El Nino doesn’t necessarily mean poor snow conditions
Avid skiers and riders are well aware that a strong El Nino has been percolating in the Pacific Ocean. As if last winter weren’t bad enough, the prospect of El Nino rearing its ugly head after a drought is enough to drive a snow enthusiast to despair. Or is it?
“We talked about El Nino quite a lot last winter, but in fact if it did form it only formed for a month or two,” said John Livingston, head meteorologist at the National Weather Service in Spokane. “As opposed to this year, where it looks like one of the strongest on record, which is saying the sea surface temperatures down along the equator, off South America and across toward Indonesia, are going to be among the warmest ever measured.”
The El Nino Southern Oscillation (ENSO) is a cycle of warming and cooling temperatures in the tropical central and eastern Pacific. El Nino is the warm phase of ENSO and La Nina is the cool phase. A La Nina forecast will have skiers and riders in our region dancing in the streets. But historical averages lead us to expect that in the Pacific Northwest, temperatures will be above normal and precipitation will be below normal with El Nino.
That’s not the recipe for a good season, but there are reasons for positive thinking. For one, after hanging around for nearly two years, “The Blob” and the “Ridiculously Resilient Ridge of 2013 (RRR),” a pair of climate phenomena that have contributed to our unusually warm, dry weather, have gone away. The departure of these malingerers could make a repeat of 2014-15 winter conditions unlikely.
The RRR, christened by meteorologist Daniel Swain on the California Weather Blog, is a persistent region of high pressure that emerged off the West Coast in 2013. The Blob is an area of unusually warm water in an area of the Pacific that at one time extended from Hawaii to Baja California and north to Alaska.
The RRR is a roadblock that had been pushing the storm track up and over the Pacific Northwest for quite some time. A recent shift in global weather patterns has seen the RRR finally go away. The El Nino occurring now is finishing the job on The Blob.
“It’s widely held that the RRR created the blob,” Livingston said. “With the switch in the global weather pattern, storms coming across where the blob used to sit have stirred up the water and it’s disappeared.”
Strong El Ninos usually generate big winter storms across the northeast Pacific that have a good chance of passing over our local ski areas. Forecast models show El Nino true to form, spawning a queue of storm systems in the Gulf of Alaska.
There’s more good news in the short term. Cliff Mass is a University of Washington atmospheric scientist who provides a running commentary on climate with his blog (cliffmass.blogspot.com). According to Mass, this week a pattern is forming that shows the jet stream slipping south of us in a cool northwesterly flow with an embedded trough of low pressure. This is a strong snow forecast for higher elevations. The northeast mountains and Idaho Panhandle could expect from 6-8 feet of snow this weekend.
Historically, El Nino has its greatest effect on temperature and precipitation for the Pacific Northwest in January. Toward the end of the season those effects have tended to weaken. We could have some good powder days in November and December. We may have to settle for carving on groomers in January and February. With any luck, conditions could improve to finish out the season.
However things turn out, meteorologist Larry Schick at powderpoobah.com assures us that this season will be a big improvement. According to Schick, snowfall was about 70 percent below normal statewide last season. He predicts this year it will fall only 20 percent below normal, mainly in lower elevations. He also pointed out that even the worst historical El Nino seasons weren’t as bad as last year.
It’s time to move on.