Friday the 13th Snowstorm in January, 1950 still rates as Sea-Tac's snowiest day
January 1950 is chock full of weather history in Seattle as an unprecedented series of arctic blasts pummeled the city for a full six weeks, but perhaps no event was greater than the snowstorm that hit nearly in the middle of the mayhem: A blizzard on January 13th -- Friday the 13th, no less...
With arctic air already well entrenched and a few snow falls already under the city's belt just after the calendar turned 1950, a monster 983 mb storm rolled in off the Pacific Ocean into around Astoria, dropping copious amount of moisture into the freezing air. And with the storm tracking in from the south, it pulled in even colder air out of B.C.
Seattle would go on to get about 10 or so inches of snow in the city, but Sea-Tac would measure 20.0" of snow - still the greatest one-day snowfall on record there. (Seattle did manage to register 21.5 inches of snow during the Feb. 2, 1916 blizzard -- long before Sea-Tac was built.)
In addition to the snow, it was quite cold with a high of just 19 and a low of 11 that day.
"High winds lifted the waters of Elliott Bay onto the waterfront and frozen salt water instantly stuck to anything it splashed," local historian Paul Dorpat wrote on HistoryLink.org.
Low temperature records would fall for the next six days as the snow kept coming, although mostly adding about 1-2" here in spurts.
Seattle abruptly warmed up on the 19th climbing all the way to 42 degrees. The 20th and 21st must have felt like summer with highs of 48 each day and a low of only 42 on the 21st! But it wasn't time to run outside -- it rained quite heavily those days. (Can you imagine the slush?)
After a typical Seattle January rainy 22nd, we started cooling off on the 23rd with even some snow late.
By the 24th, it's back into the ice box with highs in the mid 20s and lows of 10 and 7 for the 24th and 25th, respectively; both records.
The 26th was greeted with another mega snow event -- 10" in Seattle, but surprisingly, not a record low as it "only" cooled to 21. Snow tapered off on the 27th as lows dropped to 19.
And then, as if Seattle hadn't suffered enough that month, came the mini-ice age: A brutal seven-day stretch of single digit lows between Jan. 28 and Feb. 3 (7, 6, 7, 0, 1, 8, and 8). Doesn't look like it snowed much then, so I'm guessing it was one of those blazing sunny but bitter cold Fraser Wind days. The zero degree reading on Jan. 31 still stands as the all-time record low temperature in Seattle. Aside from that 0 and 1 degree low, Seattle's next-coldest low since 1900 is 6 degrees.
Finally, on Feb. 4, it warmed to 41 and the weather became relatively sane after that. Even today, 18 of the 34 low temperature records from Jan. 1 to Feb. 3 are still from 1950 --12 of them in single digits. Only two of the Jan. 1950 lows that had been under 20 degrees have since been topped -- Jan. 12 (18 degrees in 1950; 13 in 1963) and Jan. 27 (19 in 1950; 11 in 1957).
With Seattle undergoing quite a bit of growth in the past few decades, those 1950 record lows may stand the test of time. Urban areas stay warmer at night than rural areas as asphalt and concrete absorb the day's heat better than vegetation/grasses, meaning Seattle generates a bit of its own overnight warmth.
The last time Seattle was in single digits was a 9 degree low on Dec. 23, 1983. Seattle hit 12 a few times in December, 1990, but even lows under 15 are exceedingly rare these days-- just twice since 2000 (both 14 degrees.)