9:34 AM: Thanks for all the tips/questions/photos of military helicopters that have made a few passes. These kind of helicopters don’t usually show on trackers but we’re checking around. So far we’ve reached somebody at Joint Base Lewis-McChord, who says it’s not theirs. … As for a Seahawks flyover, that game isn’t until 1 pm.
Image search says the helicopters are Boeing AH-64 Apaches.
(Added: Reader video from Brandy DeWeese)
10:14 AM: Thanks to the commenter with the tip. The Boeing Field operations hotline confirmed to us it’s practice for a Seahawks flyover later and that they are Army helicopters but not from JBLM.
11:11 AM: None other than the 16th Combat Aviation Brigade just replied to us and tweeted directly that the helicopters ARE from JBLM – two BlackHawks and two Apaches – and were indeed practicing for the game flyover. “They flew up from (JBLM) this morning to work on their timing.” (If you follow the link to the tweet, you’ll see video of what it looked like from the field.) So again, that means you’ll likely see/hear them again before the 1 pm kickoff.
ADDED 2:35 PM: And indeed, they returned. Jessica got a closeup look south of Fairmount Park:
Lumen Field tweeted a photo of the view from there.