The sound was from someone practicing the shofar. Shofars were blown this weekend on Saturday and Sunday at Greenlake and Golden Gardens, Queen Anne Hill, and other locations, at Taschilich ceremonies celebrating the Jewish New Year. The sounds carried for several miles, as I learned from my experience. It is considered good luck to hear the sound of the shofar.

Great article, thanks for looking into this. We heard the same mournful horns near Green Lake and were wondering about their origin. Also nice to read some local news that is merely interesting, and not existentially distressing.

It was audible in Fremont, and it sounded like it was coming from the Ship Canal, actually

Sound can travel quite oddly. Many years ago, on a very snowy night, Mr. Vel-DuRay and I were rousted from a deep sleep (each in our twin bed of course) by a woman screaming for her life. We thought it was the woman next door and called over there. She had also been awoken by the screaming, so we called 911 and looked around our respective lots and found no evidence of anything going on.

It turned out that it was a woman down in front of the 711 on Rainier Avenue (several blocks away, and at a lower elevation) having some sort of seizure. That sort of thing goes on all the time down there, but it was because of the snow or something, it sounded like it was coming from between our house and the neighbor's house.

There is a NOAA ship docked at NOAA contiguous with Magnuson park, and it occasionally lets out a "fog horn" (typically five times) to indicate that either: (a) it's pulling out (often just to turn itself around) or (2) someone is getting too close (still have some federal 9/11 restrictions adhered to). And indeed it blatted its" fog horn" (five times) during the peak of the smoke. That's my worthless bet as to the origin of it - albeit Magnuson park to Maple Leaf is quite the distance.

Sorry, folks! That was me. I farted.

Ducting is also why sometimes you can pick up distant FM radio stations, even though FM signals don't "bounce" the way AM signals do.