Forecasting snow around here can be witchcraft
By ANDY WAPPLER
Mercer Island Reporter Contributor
December 23, 2008 · Updated 1:48 PM
It’s only a rumor that most snow forecasting is done by flipping a coin, but sometimes it might as well be “heads it will snow” and “tails it won’t.” Few things can frustrate like a snow forecast in the Puget Sound area, where a shiny quarter seems as helpful as the latest computer model or satellite image.
Snow is a tough forecast in our area for a lot of reasons. While there’s no such thing as being “too cold to snow,” there is a tiny bit of truth in that old saying. When the air gets cold, it also gets dry, and that means you need to add a little moisture back into the picture if you are going to have snow. The trick is in adding exactly the right amount of moisture, and we usually overdo it. In our area, adding moisture back in means getting a blast of wet air off the Pacific (which any salmon will tell you is a very moist ocean). Unfortunately for snow fans, we often go overboard on the moisture thing and end up with a sloppy mix of rain and snow that turns to rain far too soon for fun on the big sledding hill. But, get that mix exactly right and the results can be pretty impressive, with “impressive” being a code word for sliding into a ditch.
Our hills and elevation changes complicate the forecast also, with many storms bringing snow to some neighborhoods and leaving others without a flurry. Add in all the microclimates around the Puget Sound area and you quickly have a dazzling number of different scenarios for every storm. Every snowflake is different, they say, and so is every snow storm.
Most years, SeaTac airport, which is generally used as the benchmark weather reporting station for our region, gets about 11 inches of snow for the season. Some years, we won’t see a flake. And here’s a statistic that will win you a friendly wager (and the admiration of your spouse and children): our all-time record for a winter’s snow at SeaTac is an incredible 67 inches from 1968-69. For sure, we’ve all now had plenty of winter, and winter has only just arrived. If you haven’t taken a few minutes to get a storm preparedness kit together for your family, get to PSE.com. The Web site has some great tips on how to be ready, and links to organizations such as the Red Cross. A good plan at home with a three-day supply of all you need, and an emergency kit in every vehicle, is a comforting thought with many months of snow, ice, rain, wind and what-not still left on the calendar. Blizzard or bust, snow forecasting is a tricky thing and always will be. Heads or tails, you call it for the next snow. Regardless of the weather, being prepared always comes up a winner.
Andy Wappler can be reached at AskAndy@PSE.com.