I'll stick my head out and give my opinion on this. There are lots of
folks who have been doing this a lot longer than I have and have much
more experience so perhaps they'll share their opinions.

I'll start off by emphasizing what is hopefully obvious. Safety should
be your primary concern here. Your home is probably the safest place
to ride out any high winds and your car is probably one of the least
safe. If you're going far (IE, Gray's Harbor from the Seattle area)
it's best to either do this before the wind storm starts or after, and
ideally in daylight. Trees fall on cars and kill people every year in
these storms and even a tree that's already fallen could prove quite
deadly if you happen to come across it in the dark at 60mph. It's also
likely that fallen trees could block your route until cleared. Nothing
more frustrating than driving two hours and finding yourself stuck in
Aberdeen instead of getting to the beach.

I suspect that people's efforts would be best focused on marine birds.
Since the weather has been inhospitable to land bird migration for
several days, the likelihood that anything will be flying to get blown
off course seems low. Besides that, most of the passerine migrants
have already long since passed by. Additionally, since winds will be
out of the west and the land birds the migrate west of the Seattle
area are roughly the same as the ones the migrate through, even birds
blown off course would likely be the same expect species we commonly
see I would imagine.

There's always a chance that a bird could have been blown in from
Asia, but the likelihood of a bird surviving the trip and then
happening to be in the bush you're looking in is low enough that I'd
focus my efforts elsewhere for the immediate post-storm birding.

I'd say the best chance of seeing something "good" would be large
bodies of water, ideally marine areas with good vantage points.

As I read the forecast, it looks like the "eye" of this thing is
currently looking like it will pass right over Gray's Harbor. I'm not
sure if the low pressure system as the center is strong enough to keep
birds stuck there the way they do in hurricanes, but it seems
possible. I'd say you'd have a good chance of seeing some birds that
are hard to see from land such as our common tubenoses, Kittiwakes,
Sabine's Gulls, Pomarine Jaegers, and Red Phalaropes if you did a sea
watch at the mouth of Gray's Harbor (either Ocean Shores or Westport)
on Sunday morning. Rarer species could certainly be encountered as
well. I believe Mottled Petrels are expected well off shore in our
area this time of year, so it's easy to imagine one getting blown in.
A similar "atmospheric river" brought in a Frigatebird (not sure if it
was ID'd to species?) to the Oregon coast last year, I believe.

If the storm is really pushing it could push some of those same birds
overland or up the Columbia river so it could certainly be worth a
trip to your local bodies of water to see if anything interesting
turned up.

When I've tried to predict a push of pelagic birds into Puget Sound,
I've typically looked for strong winds out of the west at Neah Bay and
ideally winds out of the north in Puget Sound itself. The theory
obviously being that the birds would be pushed into the sound and fly
around a while before figuring out how to get back to where they came.
It was conditions like this that led to the day where many people saw
Northern Fulmars and Black-Legged Kittiwakes last year.

As I read the forecast, those conditions are not really set to occur,
but things can change rapidly (The forecast appears to have changed
even since I started this mail) and if I wanted to bird on Sunday
morning I'd certainly head to Puget Sound with my spotting scope.
Location wise, I assume the close to the ocean you get the better.
Cape Flattery (Neah Bay), Fort Warden, Fort Casey, Point No Point,
Edmonds, Richmond Beach, Discovery Park, and Alki Point all seem like
good spots from best to worst. There may be nothing at all, but even a
bad day birding is better than a good day raking leaves.

While seawatching in marine areas, more time spent looking will turn
up more and more as the birds are constantly moving. If you show up
and merely do a couple scans of the water you'll miss a lot. Think
three hours minimum.

Here is the forecasting site I'm using, btw. Someone just linked me to
it and I like it because it quickly allows you to see wind direction
and speed throughout the day:
https://www.ventusky.com/?p=47.48;-124.01;6&l=gust&t=20161015/22&w=0xIAb9A9A

I've also used this one in the past:
https://www.windfinder.com

Josh Adams
Cathcart, WA