If you head south from Katahdin later that August, you may end up having to wait at times for “weather windows” - particularly in the Whites. There have been many weeks this Fall in the Whites where the hiking above tree-line was almost impossible - hurricane force winds, sub-zero wind chill and almost zero visibility. Of course, there have been a few weeks of ideal conditions as well.
My two cents of advice would be to make sure that you wait out bad weather in town and not get caught in brutal above-treeline situations. Timing is everything. Carrying a weather radio may be a very good idea as well - you would have a better idea of when to bomb off the trail.
Rime ice can be a big factor on all the exposed granite - I can’t imagine trying to get down Mahusooc Arm, or any other cliff like section of trail on rime. Snow deep enough (say half a foot) to bury the trail makes for interesting navigation issues, particularly since the blazes are white! (Yesterday I XC skied a section of the A.T. in Pomfret VT - the snow was about 8" deep)
Every year is different - check out “Squeaky’s” '05 triple crown hike on TJ’s. He started SOBO from Katahdin on October 15th and got buried by 4 feet of snow in the Mahoosuc’s… He figured that the PCT & CDT would be the hardest part of his journey, but the SOBO leg on the A.T. through the Fall into Winter turned out to be the hardest part of his long hike by far.
All things considered, if I were planning a Fall/Winter SOBO hike, I would want to get as far as Glencliff, NH by late October - on an ‘average’ year. After Moosilauke, its mostly a ‘walk in the woods’… ‘:)’
Happy Trails,
freebird
freebird