Need help selecting outer wear for the JMT

What about this combination:

Marmot Ion Windshirt (hike in this breathable windshirt when cold+ windy)
MB UL Inner Down Jacket (for camp and if needed to supplement sleep system)
Buy a Driducks jacket (stays in the pack unless sustained or heavy rain)

Here's a Driducks set on ebay for $15.00 (I just choose size L to get an url): http://cgi.ebay.com/NEW-FROGG-TOGGS-DRIDUCKS-RAIN-GEAR-JACKET-PANTS-KHAKI-L-/310325174904?pt=LH_DefaultDomain_0&hash=item4840d26278#ht_1257wt_1141

This 3 piece combo should not much heavier than your 1st choice.

Edit: I know this means buying add't clothing, but the Driducks is pretty cheap!

I'm so tempted to buy a Driducks set to replace my Precip jacket. My Precip is one of the heaviest and bulkiest items in my pack.

Steven:
I have been giving the DriDucks a lot of thought lately and could see them as an inexpensive alternative, which I wouldn't mind going with. With the DriDucks jacket, the Marmot Ion, and the Montbell Down jacket, that would put the total weight to approximately 19 oz. Not sure if its worth the 5 oz savings over the Precip setup.

Clothing seems like one of the hardest things to pin down with any finality. In the last few years, I've bought a Driducks jacket and a NF Triumph pullover shell in addition to a Patagonia Rain Shadow I already had. Any one of the 3 would be fine but I keep trying to realize that PERFECT combination.

I do take a breathable hooded windshell and have totally bought into using one for wind, cold and light rain. I still will carry one of the above waterproof shells though in the PNW and I would probably do so in the Sierra too b/c the margin for bad weather is too great, even though you'll probably have great weather.

Good luck deciding!

My take: the $15.00 for 5 oz lost and a more versatile system is pretty good in UL currency!

I took an ID silnylon cape (never used), a Montane windshirt and a MB UL jacket; that was walking in July though – about 430g

Later in the season (as you are) I would probably replace the cape with my TN Triumph anorak for an additional vast 36g penalty.

I would not do the JMT without a waterproof upper layer. You won't be warm or dry while hiking in a windshirt + Thermawrap if freezing rain is coming down… you would have to stop and set up your shelter if you encountered bad weather. I would go at the Precip with some scissors, save a few oz, and bring that + the down parka.

Andrew

Here's what I decided on after reading the suggestions here.
Montbell UL Inner Down Jacket – 9.6 oz.
DryDucks Rain Jacket – 6.4 oz.
Marmot Ion Windshirt – 3.7 oz.
Total Outer Wear (Upper Body) weight – 19.7 oz.

Thanks again for all your suggestions.
Jim

^ exactly what i would have recommended. You could even scratch the wind shirt and just put on the rain jacket for that situation..

*oh and you might as well get the Inner parka (same thing just with a hood..)

Use your down and Ion and get a poncho tarp.