LOW RUMBLE ALERT: Western Washington/ Seattle low wumbling noise right now.

Hi all,
I've been reading GLP for some time, but this is my first post.

Starting about 9:00pm PST tonight to the present time as I write this note, I have been hearing an intermitent low rumbling noise in the sky.

I am in my backyard, where it is a quiet clear night in Western Washington and hear this intermitent low rumbling sound that is quite noticeable. It lasts about 40-60 seconds and it is the same intensity through that entire time. I asked my friend who was outside with me at the time if she heard it and she confirmed that she heard it as well. She thought it was a neighbor playing a shooter video game, but it was not. I also asked my good buddy to come outside and he also confirmed he heard it. He is a radio operator and started scanning all UHF/VHF freq's and could not hear any military activity in the sky's. Although, it does sound like a jet doing a low pass, those are very distinct and the intensity of the sound wave does gradually pass. However, not this sound.

I live in Redmond, which is a suburb 15 miles east of Seattle. When the sound does appear, the dogs in the neigborhood start barking and howling. When the sounds stops, the dogs stop.

I am a pilot and have been listening to aircraft and airport noise for decades and i can tell you, it is not that sound. As a matter of fact, I can hear aircraft coming through the seattle center approach into seatac and KPAE, and the low rumbling sound is actually under and lower thant the aircraft noise.

There is no contruction radio chatter, no trains coming thru town, and there are not delivery trucks in the area.

I have heard about these noises on previous threads, but this is the first time I have actually ever heard this. It is very fascinating but eery at the same time.

If there are any GLP'ers in seattle area or suburbs now, can you hear it too? Let us know if you do. It is very quiet in my neighborhood though, and I do live up in redmond ridge so I am on a hill, maybe that is why it is very distinct and clear sounding low rumble noise I hear.

Thanks and I'll update later if I can hear in the next few hours.

Regards,
Gooch