Monday, December 20, 2021

Seattle Weather

When we moved to Seattle twenty-some years ago, I started encountering weather features and climate conditions that I hadn't encountered before, or had few references to. Here's a handy list for new arrivals:

Weather Forecast: Fiction. 

5-Day Forecast: Science Fiction. 

Mountain Day: We are surrounded by mountains - Cascades to the east, the Olympic range to the west. But when we say "The Mountain is Out" (and we do), we are talking about Mount Rainier (rah-NEER), which looms to the south like something out of Greek Myth.If we can see it from base to tip, we call it the "Full Mountain".  People are usually happy when we can see the Mountain, despite the fact that Rainier is an ACTIVE VOLCANO (not erupting, but not quite dead, either).

Sunbreaks: The opposite of Partly Cloudy, but rarer out here. It a term used from the Fall to Spring, and usually means "You might see some sun today." Most of the summer is pristine, blue, and cloudless. That's when your relatives from back East visit and tell you how nice it must be to live out here. You want people to stop moving to Seattle? Invite them out in the dead of winter.

June-uary: When we say "summer" in Seattle, we don't count the first two weeks in June. Sure, May is nice, with soft rain in the evenings and fogs in the morning, but a grey overcast dominates the landscape in early June, so much so that it gets its own month. Also called June Gloom.

Atmospheric River: A recent term, it reflects the fact that Washington State doesn't really have any large agricultural states to the west of it we can call up and ask for steady weather forecasts.What we often see on the doppler radar is the thick stream of heavy red bearing down on us. Makes the weathermen on the evening news excited.

Pineapple Express: When the atmospheric river commutes from Hawaii. Really makes the weathermen excited.

Convergence Zone: I mentioned the Olympics, they are a massive upthrust of mountain due west of us. They tend to stand in the way of the atmospheric rivers that buffet the coast. Of course, the weather tends to go AROUND this big chunk of mountains, so Seattle is often at the point where the weather coming around the northern side hits the weather coming around from the south. When they hit, we get interesting, local effects. So Kirkland can get heavy rain and hail while Kent gets nothing.

Rain Shadow: The flip side of the convergence zone. Because the mountains are in the way, some places get untouched by rain while it rains heavily to both the north and south. The Olympics become Seattle's umbrella, and like an umbrella, a treacherous wind can turn it inside out.

Microclimates: As a result of the differences in altitude, plus the rain shadow and convergence zone, microclimates mean that you can have radically different weather in relative close proximity. While in certain parts of the country, the saying is" If you don't like the weather, wait fifteen minutes" in Seattle it is "If you don't like the weather, drive fifteen miles."

Misting: What Seattlites call it when it really ISN'T raining. You don't need a slicker. You don't need an umbrella (a sign of being a tourist). It's just misting. Works up to the point when you start seeing hail.

Thunder:  A rarity. It happens maybe once a month, consists of one long, rolling peel. and people will talk about it at the office the next day. It is so cute to those who come out from the Midwest. 

Snowed In: More than a quarter inch on the roads. Everyone forgets how to drive. Archaic term now that everyone is working from home.

Snow Level: Snow is measured by altitude here, and as winter proceeds the snow level descends down from the mountains to the sea. So we really pay attention to where the snow level currently is. "Lowland Snow" sets off alarm bells and closes schools. Grubb Street is located at the 500 foot mark, just in case you were wondering. 

Seattle Freeze: Has nothing to do with the weather, but is as close as we get to feeling chilly. 

Black Ice: Not a uniquely Seattle phenomenon, its the scarier way of saying "It's a little slick out there".

Closing the Passes: The main east/west highways out of/into Seattle go over the Cascade Mountains, and as winter arrives, travel over them become perilous and often avalanche-y, until finally the passes are closed, sealing us off from the rest of the northern US. We're pretty happy with that.

Polar Vortex: Not so much a Seattle thing, this is a weather effect that has been picked up on the national reports. It is bitter cold with heavy snows and wind - what Wisconsin used to call "A pretty average winter".  The weakening of the Jet Stream around the Arctic Circle results is sudden bulges of cold air descending on the heart of of the country, giving Climate Skeptics the chance to complain "Where's your Global Warming, now?"

Pyroclastic Flow: We have an active volcano nearby (see Mountain Day, above). Someday, it will go off, and send a cascade of molten rock, hot mud, and melted snow down the surrounding valleys, including the Green River valley, where Renton, Kent, and Auburn lay. This is a reason that Grubb Street is up on a hill. Have a pleasant day. 

Subduction Zone: The Big One - that massive earthquake that will cause the West Coast to fall into the sea, belongs to us, Oregon and California, so it not unique to Seattle. However, we DO talk about the tectonic plates far out to sea that have the potential to slip and create a Tidal Wave, which, given the narrowing of the Straits leading to Puget Sound, will channel it like a shotgun blast at the city.

Tsunami Route: You can see signs occasionally. I'm not sure they're being kept in order. They are usually pointing towards higher ground (well, yeah), in case the subduction zone triggers a tidal wave that will swamp the low-level areas of the Sound.

Solstice: Solstice is an important holiday in Seattle. We are the furthest north major metropolitan center in the continental US. We are further north than most of the population of Canada. So this means that our day/night cycle takes wide swings back and forth during the year. In the summer months, we are used to the sun setting in the Northeast, and twilight showing up around 10 PM. In the winter months, we are looking commuting in the darkness both to and from work. Both are a bit wearing on the senses, and the Solstice is the moment when the pendulum reaches its furthest point, and starts slipping back.

Happy Solstice. More later.