Ok, so I am leaving for California on Saturday and I am wrestling with which jacket to bring. I have both a synthetic and a down by Mont-bell. I need to keep my pack weight down due to a bad knee. My down jacket is warmer than the synthetic, but of course, if it gets wet, I am screwed. They are both about the same weight. I do layer. I am nervous because I know California had a lot of snow this last winter, so it could be cold in the evening/mornings. Any one hike JMT recently and which would be the better options?

If there's a chance you'll get rained on, I'd take the synthetic. If you're expecting to get snowed on, the down jacket will be fine. Snow brushes off, and the material of most jackets will repel a little moisture.

BTW, there's nothing nastier, IMO, than a soaked-through down coat. You not only freeze your glutes off, but the weight of the wet coat is oppressive.

Stargazer

your insulated garment will be used when sitting around camp and possibly to augment your sleeping system- down wins out in this scenario IMO, your not going to be wearing it on the go and if it does happen to rain while in camp- don your rain jacket

store it in a waterproof liner along w/ your sleeping bag and dry clothing

a soaking wet syn insulated garment is no fun either

>a soaking wet syn insulated garment is no fun either

So true, but it squeezes out pretty well and still provides some insulation when wet.

Still, your points are well taken. However, as you say, you really do have to take extra care to keep the down dry, including wearing a rain jacket with even the hint of rain and, if you're going to wear it to bed, make sure that you're protected from water blowing under your shelter. I pretty much switched to synth when I am expecting bad weather after I woke up one night with my down bag and coat soaked through and freezing cold.

It takes a lot of water to soak a down jacket through. If you truly get it soaked you probably fell in a creek without having your down jacket in a waterproof bag, or you let your shelter get flooded. Both are preventable.

Most experienced backpackers will choose a down jacket for the JMT or PCT for light weight, warmth and compressibility.

If you have the skills to keep your down jacket from getting soaked down is the better choice. If you're unsure, perhaps synthetic is a better choice for now.

This is my own personal preference, but ...

I have done many Sierra trips and I never bring down into the Sierras, whether a jacket or a sleeping bag.
But my rule of thumb is : down only if temps will drop below 10-15* so that conditions are dry.

Sierra summers are not that cold. Chances are your JMT trip will not get below 35*.
But even at 25-30* you don't need down, and for me the chance of getting the down wet precludes its use.

Lots of warm synthetics out now a days, plus layering can keep you plenty warm enough.

Edited by asandh on 07/27/2011 09:48:00 MDT.

I live in the sierra and use nothing but down. i dont own a single synthetic. I keep both my quilt and my down coat, boots, hat in a cuben dry bag in my pack. I dont use a pack cover or anything else to waterproof my gear.

If it rains, i am covered, I get my tent out, set it up, put the pack inside and then take out my down.

I carry synthetic LJs for sleep and for extraordinary conditions while hiking.

The goose down jacket would be my personal choice. Neither insulation layer works well once wetted out. Synthetic is usually just a tad more rigid a material which is why it may stay fluffy and retain a better R value for just a bit longer while wet. The thing about high quality goose down is that it breathes really well and does an excellent job at moving moisture. Wear your down sweater through a rain storm and let it wet out a bit. The thing you'll find is that if you shake and fluff the jacket and then simply wear it the down will generally be dried out and fully fluffed in a matter of a few minutes to an hour depending on conditions.

If it's going to be so wet that you'd expect to get constantly rained on I'd drop both and move to a more rigid fleece type insulation layer. I'll go to a polypro to pull sweat, a light or heavy fleece base layer and then my heavy fleece jacket topped with a rain layer for a winter rain scenario. Everything can basically get wet but I stay warm and can do heavy labor in something like that day to day even if things never fully dry out.

Sierra summer, along the JMT? Down.

Don't get your insulation wet and you'll be rewarded with a warmer, lighter, more compressible garment.

Thanks everyone for your insight. I am leaning towards the down. I most likely would not hike in it anyway and I could wear my rain jacket over it in camp if it does start to rain. Everyone enjoy your summer and happy hiking.....

I just finished the Rae Lakes loop two days ago which follows the jmt for several miles. The weather was great. I never needed more than one extra layer. There was barely a cloud in the sky.