Large wind shifts pushing cooler water to the shores are also key for great lakes surf fishing its all timing, water temp, light conditions. Browns as you know are a very smart and cautious fish. Need to fish them in low light or darkness when all of the variables are correct. IMHO late fall and early spring are the best chances at river mouths or the lower parts of rivers. Thats also when the gear anglers get them with spoons and bait, etc.
The warm water discharges are also key but darn off limits for the most part.
In Steelhead Dreams there are a couple of chapters on this.
Nothing like casting the river mouths in darkness never know if the next fish will be a steelhead, brown, or big chrome salmon. Make sure you have a saltwater fly reel setup and lots of backing.
Its fun but I never expect a big result due to the low proability of success.
Gotta go, good luck