White Christmas Chances

Wishing for a white Christmas? Could be, probably not, but could be, but not very likely. Finally, some data that shows how close a white Christmas always is.

Yes, it does snow on Whidbey Island. But, it doesn’t snow every year. That’s a relief for many. No snow to shovel, though there may be lawns to mow. Even when it does snow, getting it to snow on that one day, December 25th, makes the odds even longer.

The good news for skiers and other winter outdoors types is that we can see the snow from here. From mid-autumn through to mid-spring fresh snow can be seen on the Cascade Mountains to the east and the Olympic Mountains to the west. Head east and find Stevens Pass Ski Resort on Highway 2, or go farther south then east for at least four other ski hills. Or, go big by heading north a bit then east to Mount Baker. We’re not talking about light dusting of snows on a tiny hill. We’re talking world record snowfalls. One year Mt. Baker set the record at 1,140 inches. That’s 95 feet. On a volcano. That’s enough to cover a forest letting cross country skiers see a blank snowscape that in summer holds trails between ancient conifers. Imagine the squirrels who might not have to worry about hawks for a season. Or, go west to the aptly-named Hurricane Ridge in Olympic National Park. The slopes aren’t as large but the quiet is impressive – as long as the wind isn’t howling.

Drive to snow and come home to clear roads, all in a day.

It’s relatively easy to see how and far such seasons are on a map recently released by NOAA. It shows the probability of at least one inch of snow on Christmas. Without much surprise, saltwater islands in Puget Sound have single-digit percent chances. Altitude makes a difference. Islands tend to have elevations – let’s see – about at sea level. Saltwater in the Sound is relatively cold in summer, but becomes relatively warm in winter. The water temperature doesn’t change much, but the air temperature ramps up and dives down. Whidbey Island is surrounded by an enormous heat sink set at about 50F. That makes it harder for snow to stick to the ground.

Despite the low probabilities, the reality is that some places on the island are more likely to have snow. Up and in make the difference. The farther back from the water and the higher the land gets produces micro-climates that encourage snow to fall and stick and stay. It’s common for rain or slush by the water, and then a few inches of snow on the high points. Simply driving to get some groceries can be a journey from clear-and-wet to traction-tires-recommended (unofficially) to oh-dear-do-I-really need-to-buy-eggs-today.

New residents can be forgiven for thinking the locals are silly for worrying about such an event. What difference can a few inches of snow make? People who are familiar with wintry conditions drive through worse for weeks or months. But those places have more plows and more experienced drivers.

On the island, snow can surprise folks. Local forecasters might suggest the region will get some cold rain, and quickly mention “except possible snow showers in the Puget Sound Convergence Zone.” The PSCZ is a regular occurrence, a narrow band of clouds that form when storms systems recombine after being split by the Olympic Mountains. The PSCZ can form without warning, frequently north of Seattle, as in over Whidbey Island. Within a few miles some people can think they’re in a blizzard while their friends on social media are posting photos of rainbows.

The snow’s departure is encouraged by the few plows available, but in true island fashion, nature is allowed to set the pace. Rain can be more powerful than sunshine at melting the snow and ice. Especially in winter, the Sun doesn’t shine everywhere. Tall trees, short days, and lots of clouds mean waiting for a melt could mean waiting for spring. The rains, however, are more reliable and get everywhere, everywhere. Messy, but effective – eventually.

So, how about a white Christmas in 2020? Predicting anything in 2020 is a silly idea. Maybe we’ll get enough for cross-country skiing on the beach, or maybe we’ll continue to set records for a very dry December.

Despite the low probability, listen for proof of folks who learned lessons in previous years. The crunch of studded snow tires announce someone’s desire to deal with snow, slush, and ice. You see, there was this Christmas when it snowed and stuck for days… Or was that in January?

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