For the past couple of weeks, Seattle has found itself in the bullseye of the Olympic Rain Shadow.
Check out the Pineapple Express last week that dumped 7″ of rain in the mountains … and a whopping .01″ on Downtown Seattle (a 700-fold difference):
(Image courtesy of the super-cool Kiro 7 Stormtracker @ http://www.kirotv.com/s/weather/interactive-radar/)
Now, seeing the rain shadow represented as a graphic on a digital map is all well and good, but actually experiencing it is something else. Today, I did just that. Experience it, that is.
I left a partly sunny Downtown Seattle shortly after 1pm, and when I got to the Seattle/Tukwila border at 1:10pm, the skies began to turn grey.
When I arrived at Sea-Tac Airport at 1:20pm, it began snowing. Since it was 39 degrees, the snow didn’t stick, but it was falling out of the sky at a pretty good clip.
When I got on SR-518 at 1:24pm for the return trip to Downtown, snow began falling more heavily under very heavy cloud cover.
When I got to the SR-509 interchange 2 MINUTES LATER and only ONE MILE AWAY from the snowstorm, there was nothing falling from the sky, and the cloud cover was substantially thinner.
When I got back to the Seattle city limits, only 3 minutes and two miles from where I took the snowstorm pictures, I could see definite sunny skies.
When I got to the West Seattle/SoDo border, only 5 minutes and four miles from the snowstorm pictures, I was once again under partly sunny and dry skies.
And that, boys and girls, is the Olympic Rain Shadow illustrated.
The Olympic Rain Shadow is the reason that Seattle gets only 38″ of rain each year, while towns like Aberdeen, Montesano, and Forks get over 70″.
The Olympic Mountains are not the only rain shadowers in our area, however. Few people are aware of this, but Olympia, Washington is also within a rain shadow. It is in the shadow of the Black Hills.
Peep this, my homies:
Look at this map, and note the locations of the towns of Elma and Olympia.
These places are at roughly the same latitude, and they are only 25 miles apart, yet Elma gets 69″ of rain annually while Olympia only gets 50″.
“Oh my god, Rex, you are blowing my mind! How could this possibly be true? How can you explain it? Is it magic? It’s magic, isn’t it? Go ahead, you can tell me, I’ll keep your secret! It’s magic, right?”
Believe it or not, it’s not magic at all. Do you see that big green area between the two towns?
Well, those are the Black Hills, and clocking in at over 2,000′, the hills are high enough to rain shadow Olympia to a significant degree.
Be they large or small, rain shadows are major factors in the weather of the Pacific Northwest.