I am thinking of getting either a WM flash vest or Montbel EX Light Jacket specifically for hiking the JMT this summer. Which do you think would be better for an insulation layer? I will have a long sleeve shirt, and silk base layers with a rain coat when needed. Thanks for any input on this.

I'd bring the full on jacket. Mornings at elevation are often around freezing. Eat the 1-2oz penalty, and actually be comfortable enjoying your hike

I have used both a vest and jacket at high elevation for my insulation layer and I did the JMT with a WM vest and was not cold and of coarse I had a layering system. The morning is always cold but you soon warm up. I just got a new WM Flash vest at 6oz for the up coming season. IMHO it is up to you and where your genetic roots are from. Either way would work just fine.

If I get a coat should I then get one with a hood, or should a beanie be more than enough, I was thinking WM Flash coat.

I hiked the JMT last year (11'), it was a great time. I had 2 coats, a down jacket ~35-40 degree style that I made myself and a 3 oz wind breaker.
I would wear the down with a wool beanie during my dinner, breakfast and morning camp breakdown. Then I would switch out the down for the wind jacket and start hiking.

I vote for the jacket because it can get pretty cold at higher elevations. Some mornings the tent had frost on it and the trail was icy.
Stay warm and have a good hike.
-Dale

I'd lean towards a coat. Maybe its just me but I feel like my body has a harder time keeping me warm when I'm all tired out.

I've never really understood the vest thing other than as a fashion statement. I'm sure it serves a purpose for many but when my torso is cold my arms are too and require cover. I would recommend the Montbell EX Light for the JMT. I have a Montbell Thermowrap parka that has served me well on many miles along the JMT both in the cold mornings and evenings as well as those occasional below freezing nights when I wore it to bed. If you get the EX please get a size large--in case you don't like it I'll buy it.

Don

That is what I was thinking, getting the coat, does not weigh much more. Are there currently any sales on this coat?

I did trail work up there most of the summer this year, and I felt my NB Fugu jacket was overkill. I would like to have had a lighter down vest. A very light base layer might be nice when it's not possible to hike fast enough to put out a lot of body heat, like when crossing icy passes where the going is slow.

Eugene, I think the fugu is in a different category altogether. A jacket like that is def overkill given its down fill weight (winter appropriate for CA). OP is looking at vests/jackets with only a couple ounces of down fill

Konrad, you may be right. I have a vest arriving today that I'll be using during a trail project that starts tomorrow. It'll probably get cold enough to know if it'll work on the JMT during the summer.

A jacket would be nicer, but I have a WM vest. I use the vest, a Polartech 100 shirt and throw on my 4oz. anorak in the wind where needed. That's my insulating layers for summer trips. It does freeeze. I've been in the Sierra for years now. However, a few August's back, it did get into the low 20's or lower when a snow storm came thru I've heard from Paige.

Duane

I personally would bring the coat. I have been snowed on at least three times in August. Lots of frozen mornings. If you are fast enough you might be able to camp low and not bring one, but I like all the high camps.

"If you are fast enough you might be able to camp low and not bring one, but I like all the high camps."

I agree, the high camps are sooo much better. The lower sub-alpine camps are usually among dense trees, mosquito infested, and lacking in views. We tried our best to camp above treeline, even if it meant colder mornings.

The reason for a vest instead of coat, is that the torso skin temperature is warmer than your arms.

Therefore, insulation over your torso results in less heat loss than insulation on your arms.

Heat loss = Temperature difference across insulation / insulation value

But, lots of people like vests, and lots like jackets - either works

I now need to decide if I need a new one. I have the Sierra Designs Gnar hoody at 390 grams and love this coat, I need to decide if it is worth $190 to save about 190 grams, what do you think? To get the Montbell EX light down or not.

Look at Patagonia or Western Mountaineering. True and Tested!!!!

2 cents worth

Jay, the Montbells are true and tested too. In fact Richard Nisley has done a lot of testing on the clo values of MB and patagonia. MB is also usually noticeably cheaper than any competitor's product with similar performance/specs.

As for the OP, I'm a big fan of having a hooded insulating layer. On paper you lose some performance (down to total weight ratio decreases) but having your neck and head well insulated provides far more "warmth" than a jacket and hat in my experience. Really I would only consider a vest as a supplemental insulating layer in case I was between a light inner parker and a heavier winter parka (or in AZ summers as a sleep system!).

I'd say 'Jacket.' One late July morning @ Garnet Lake, my wife rinsed out her bandana and hung it over a bush to dry. 5 min later, it was frozen stiff when she picked it up.

With your other gear, You will almost never need either jacket or vest when actually hiking the JMT in summer. So it's just for rest stops, around camp, or to supplement your sleep system. For that reason I would go with the lightest hooded long-sleeve option.

(Currently I'm very impressed with my daughter's Stoic Hadron down anorak at 8 oz.)

Edited by jimqpublic on 01/14/2012 22:47:54 MST.