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Could be a little wetter this winter than last, and there could be a bit of valley snow, forecasters agreed.

ERIC NORBERG - These are the presenters at this years What Will Winter Be Like AMS meeting at OMSI on October 26: From left, Kyle Dittmer, Columbia River Intertribal Fish Commission; Tyree Wilde, National Weather Service, Portland; Kelley Beyern, KOIN-TV-6; Mark Nelson, KPTV-12 and KPDX-49 Television; and guest speaker Dr. Cliff Mass of the University of Washington. For 27 years, the crowd attending the annual "Winter Weather Forecast Conference" of the Oregon Chapter of the American Meteorological Society has grown each year – as word of this genial prognostication party has spread. In fact, this annual meeting held in the OMSI Auditorium in late October must get some of the credit for this local chapter having the most members of any chapter in the country; annual dues are just $10, and members are signed up at the back of the auditorium during the meeting.

The date was October 26 this year, and the two-hour meeting expanded to three this year only, to accommodate a lively illustrated lecture on the "Pacific Blob" by Dr. Cliff Mass of the University of Washington, before the winter forecasts got underway.

Dr. Mass explained that this large area of warm water in the North Pacific Ocean appeared in 2014, and returned this past summer. The "Blob" of warm water is caused by an area of persistent high pressure in the eastern Pacific, he explained, and reduces the mixing of water at different depths of the ocean, warming its surface. This has the moderating effect we all noticed this summer of warming the overnight lows in western Oregon and Washington summers, while moderating extremes of high temperatures in the daytimes – although the overall temperature trend is higher in these summers.

He went on to address the question about whether such summers could worsen the wildfire risk in the Northwest. Using intricate, high-resolution computer modeling he has explored this question, and finds that "Blob" summers could actually reduce the fire risk a bit, by reducing the incidents of gusty east winds which usually fan such fires. However, since higher temperatures increase the risk of wildfire, he said that it is hard to quantify the overall effect on fire risk. But higher temperatures may not worsen it, in any event.

After Dr. Mass concluded his talk and answered questions, the regular "What Will Winter Be Like" meeting got underway as it always does – with Meteorologist Mark Nelson of KPTV and KPDX television summarizing how the last winter turned out. Mark remarked that the past winter was the most boring one he could remember – until February and March. That's when snow and the interesting weather blew in, and snow levels returned to normal for the season in western Oregon.

Nelson added ruefully that some of the snow forecasting in February sounded apocalyptic – but weather does change as it approaches, and forecasters eventually realized that the massive snow event they saw coming was swinging away from Portland, and walloped Eugene and Roseburg instead. But, he pointed out, those early forecasts were being repeated and amplified on "social media" long after the forecasts had been corrected, and what was being gossiped about was no longer going to happen. People still cleaned out the grocery stores here in preparation for what did not happen. Then came the new winter forecasts from three forecasters. First was Tyree Wilde from the National Weather Service office at the Portland Airport, who pointed out what all the Meteorologists acknowledged – unlike last winter, when "El Nino" caused a drier than usual season, this year appears to be "neutral", and neither "El Nino" nor "La Nina" oceanic warming conditions apply in the western Pacific Ocean. In such years, there is no strong weather trend, but there can be a lot of variability in the winter weather. So, even though the NWS prediction is for average temperatures and average rain and snow, it might get interesting at times, and it could be a decently snowy year.

ERIC NORBERG - Kyle Dittmer always presents the most thoroughly-detailed forecast for the upcoming winter - and the hardest one to read, on his slide, due to the very small lettering such details require. But, he said, it should be a pretty average winter, with some decent snow in the city.The second forecaster was Kyle Dittmer, Hydrologist and Meteorologist for the Columbia River Intertribal Fish Commission, who has presented a forecast each year at the conference for the past two decades. As with most Meteorologists at this conference over the years, Dittmer selects "analogue years" from the past in Portland to project what we might see this year. Dittmer is an advocate of including the sun's sunspot cycle in this selection, and chose 1964, 1975, 1985, and 2009, as the years be believes are most analogous to 2019. He expects normal winter temperatures in Portland, with January wetter and perhaps slightly warmer than usual, and a wet April and May. He predicts seven snow events in Portland starting in December – "two medium, and five minor" – with a season snow total in Portland of 7.5 inches.

The final forecaster was Kelley Beyern of KOIN-TV-6 who, it was noted, was the first female private forecaster ever to present a winter forecast at this conference, although the National Weather Service had previously also been represented by a female forecaster. More women are entering the field, and more female participation is expected.

Beyern chose her own analogue winter years as a guide – all of them years following El Nino summers – and she expects 9.2 inches of snow for the season in the City of Portland (and, like the other two forecasters, she also expects a good snow year at Mt. Hood) – even though this would be the fourth good snow year here in a row, and we've never before had four good snow years in a row.

Her specific snow forecast for Portland is for an inch in November, four inches in December, three inches in January, and one inch in February. She also predicted near-normal rainfall levels here (which would be better than we experienced last winter); and perhaps a sizeable windstorm at some point.

At the conclusion of the conference, all the presenters sat at the edge of the stage in the auditorium at the Oregon Museum of Science and Industry and answered audience questions. The concluding question was directed to Dr. Cliff Mass, who began the morning with his featured talk on the "Pacific Blob": To what extent is the generally rising trend in temperatures a result of natural processes, and a result of man-made influences? He responded that, in his view, up to the last few years the predominant influences were natural; at present, he thinks the influences have become about equal; and by the end of this century, man-made influences will predominate.

However, he said, there are many influences in weather, and there are many legitimate views about these influences, and he encouraged everyone present to thoroughly consider all points of view, and maintain an open mind – "in weather, and in everything else."

For that, he received a hearty round of applause.


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