I'm looking for a sleeping bag, probably about 30 degrees F, that can be left compressed for extended periods (like 6 -8 months) without significant damage. Anybody know the synthetics well enough to answer this one? Thanks, jcp

I don't think that kind of bag exists. Synthetics break down faster than down bags, and while down shows remarkable recovery after being compressed, I wouldn't leave a down garment or bag compressed tightly for more than a week tops. Just not worth it to destroy an expensive item that way.

That <del>lunatic</del> er, sorry clever businessperson Wiggy used to claim his bags could be compressed indefinitely, but I question the practice with any known fill.

What are you trying to achieve?

My question exactly!

My granddaughter lives in an area where she has been in danger from weather quite regularly lately (she's program director of a camp for "at risk" kids -- in the hills near Little Rock). She's had to run twice in the last year, once from flood, once from tornado. I want to put together a "go bag" that would allow her to camp in a safe area not too far away with gear she would not have to scrounge up and pack (she had only a few minutes warning on the tornado, and the flood came up fast). Her skills are very good. Best and thanks, jcp

Okay, got it. I'd guess an inexpensive synth bag, so long as it's not packed too tightly, would retain a good deal of its loft for a long time so long as it's well sealed and not subject to moisture. An alternative could be a fleece bag and extra clothing that would add up to the same warmth. Perhaps including a bag-style "Space Blanket" for added warmth and heat reflection and/or a bivy sack. Fleece should stand up to long-term compression with no problems.

Good luck!

I agree with the above. I think you should be looking for non-lofting bags. A wool blanket might be a good idea.

If she's just using this in an emergency, and you'd like to avoid spending a lot of money on a tent, you might consider an 8x10 coated nylon (not hideously expensive silnylon) tarp, plus an REI bivy sack:

http://www.rei.com/product/794292/rei-minimalist-bivy-sack-regular

http://www.rei.com/product/766383/outdoor-products-coated-tarp-95-x-8 (these come in 3 different sizes - enter "tarp" in the search box)

For about $140, you've solved the whole shelter problem. The bivy offers several advantages: it's weatherproof, which means it will add some warmth (OK, slow heat loss) to whatever you put in it, and protect against blowing rain or snow. If you use a fleece bag, it provides a shell material for it. You don't need a separate groundcloth (I never used one with it.) As I recall, mine was fairly generously cut, and it only weighs a pound and change.

The tarp isn't light compared to silnylon, but it is fully functional. There's also a 10x10 size, for $10 more, that is even moreso - using a hiking pole, it pitches nicely into a wedge that can be pointed into the wind. Not a palace, but it would work in a pinch.

Thanks much folks.

I have a well-used ID South Col bivy and REI fleece bag that I used for about three-quarters of an AT thru-hike some years ago, and I had laid these out as a possible solution. Looks like I was on the right track. I've also thrown in a set of wool long undies that I have replaced with silk. Yes, I think that should do the job, just not as compact as I'd like. I've also put in a Sierra Designs rain suit. I wore mine into the sleeping bag one very cold night and I think it helped.

Incidentally, she has a Cascade Designs 40 degree synthetic bag that I used on the cold ends of that same hike. She's been very careful with it, and we might use that, although she loves it and may not want it wrecked in the go bag. Too bad Cascade no longer makes it. It has lasted well over ten years....more like 15.

Again , thanks. Best, jcp

In this scenario, is she literally running on foot from the hazard, or is she able to evacuate by vehicle. If the latter, I would store the uncompressed bag next to your 'go" bag so that it could be compressed and taken if time and circumstances allow; if otherwise, the items suggested by others will allow her to get by.

I am not sure about your circumstances, but I personally would nto attempt to run from a tornado. I would find a root cellar, /enclosed space/ cave/whatever and hunker down. i would not care to be caught in the open

Old Ranger,

Good thinking. Both times she got out by vehicle, though the flood was driving through a lot of water, and two out of the three escape routes were blocked. With the tornado, they had five or six minutes warning and generally knew the route it was on. She was able to drive 90 degrees to that route. got a fierce bunch of wind and rain, and, as it happened, the tornado left the ground just before her camp. Mercifully, there were no kids on site either time. I was not really thinking of being out in the open in a tornado, but having what she needs in easy to carry form, probably in the trunk of her car, where the unpacked sleeping bag, in it's storage bag could safely live. The tornado danger past and she went back to camp. The flood she made it to a nearby fire house and basically camped out on the floor for two days. She had grabbed a blanket on her way out and the firemen had more. She lives in a trailer. Thanks, jcp

I've got an older (25+yr old) bag, with halo-whatever in it, that was a 20' bag when bought. It's spent years at a time compressed. The shell is in great shape and it's still usable in anything above freezing. At 45' I have to unzip to cool off.

Which leads me to observe: Maybe get a bag with a lower temp. rating than you are preparing for and when it's lost some loft later it's still in your target temperature range.

Or you might consider using an oversized stuff bag with compression straps that lets her store it uncompressed. Then, as the situation dictates, she could grab it and throw it in the car as is, or compress it and go on foot.

Or if she adjusted her expectation from 'staying comfy-cozy in sub-freezing weather' to 'staying alive in an emergency' she could use a lighter bag that would be easier to backpack, if she had to. Speed might matter and lighter is faster.
If she stayed with the car she'd be out of the worst of the weather anyway.

take what you can use, leave the rest