Guys, I'd like your input.  I currently run a set of MOD 3's on two different helmets.  Ive got one Team Wendy Bump and one Opscore Fast Bump.  I like them both, but my main beef is that during cold/windy/rainy weather I can't pull my hood over those helmets.  They are just too bulky.  The shell I use is a mil surplus USGI GORETEX ECWS Parka Woodland.  I'm hoping that the skull mount will be lower profile that the two bump helmets I currently own and allow me to pull the hood of my parka over it and still have some head mobility.  Can any skull mount owners out there speak to this?  Thanks.

The OpsCore Skull Mount looks just marginally smaller than a full bump helmet.  It looks like it might just squeeze in there but I don't know for sure.  I run a Crye "Nightcap" which I know will fit under a GI ECWG gen III hood. Both levels 5 & 6.  You can also fit a "watch cap" around it for additional insulation as required.  I know that really didn't answer your question but maybe it will help if you find out the Skull Mount is a No Go.

Please, advise regarding estimated temperature and wind speed. I have had good results by just taping the vent holes shut, wearing a Polartec beanie under the helmet and wearing a Polartec neck gaiter. In colder weather, I have a balaclava that I substitute for the beanie because it covers the ears. This setup is less restrictive than what you want to do and makes less noise. Our average ambient temperature is higher than yours but it does get cold here.

Take a look at a Crye Precision Night Cap. It's very light weight and it'll definitely fit under a hoody. If it's adjusted correctly running binos shouldn't be a problem.

X2

Yeah terrain and weather.  If you get one of the skin-tight, one-layer beanies, otherwise known as helmet liners, this will work under the bump, ballistic, and Skull Mount helmets.  As SOT said, this will work in cold weather.  But I have been up in the mountains where you really need a hood, like when the wind and rain is coming at ya sideways.  I can get the ECWS hood on both the L5 & 6 parkas over my OpsCore bump, and Revision ballistic helmets, but just barely.  You will need a neck gaitor because the helmet widens/opens up the face hole quite a bit.

There are pros and cons for wearing the hood.  Depends on likelihood of enemy contact versus the severity of the weather.  You could perhaps travel with it, then take it off for security halts.  Whatever your SOP calls for.

One other advantage of a hoody is that if you start to over heat because of moving around a lot you can easily take it off vs having to remove your helmet, take off your beanie, then readjust the straps on your brain bucket. It's definitely not a good idea to start sweating in the freezing cold.

Yeah true it adds another wrinkle to layer management.  But it is what it is.  Sometimes the weather gets a vote too.  You can't just sit there and freeze, but you can't just sit there and sweat either.  Last year I was up on this mountain and man the weather swings were incredible.  At the base it was about 50, light wind, little drizzle.  By the time I got up the near the summit, it was in the 30's, the wind was howling, and the rain was coming in side-wise.  You had to have your hood up or your face would freeze.  Once I went over the top and started back down, the conditions eased up again.

If I had been tactical, I would have had to probably adjust my layers under or at least around my helmet.  So yeah when you add in BA, not to mention NV, it complicates things.  

I know this is an extreme example but it serves to illustrate one size does not fit all.  In the desert southwest, a beanie under the helmet works pretty good.  In the high mountains, or up north, you will probably need a hood.  In the humid southeast, you could need both.

If I didn't need a ballistic helmet for the threat level, I would use the Crye Nightcap, just because it's a lot easier to carry them both.  With the helmet in my pack beaver tail, I would sport the Nightcap and a looser watchcap that would fit over it.  And then maybe a hood as required.  Much easier to pull off the watch cap when not needed than to take off the beanie and re-adjust the (bump/skull) helmet.

Edit to add:  This is not a ding against OpsCore or an ad for Crye.  I use both their products.  This is just what works for me.

Guys, thanks for your replies.  

1.  Main use conditions will be Wisconsin winters so -10 to 40 degrees with 10-25 mph winds with or without rain/snow.  Anybody who's spent more than an hour sitting still on those conditions knows how critical wind management is.  I've spent many years learning to stay comfortable in extreme conditions and the gortex shell with hood (in addition to a neck gator and beanie) is an indispensable part of that system.

2.  Those using a Crye nightcap:  I assume you use a counterweight as well right?

Thanks

1.  Yeah for you a hood is definitely something you would want.  You can even get an oversized balaclava over the Nightcap.  

2.  Yes.  I modified mine so there are two Velcro webbing straps in back, which makes the whole rig mo solid, and gives you a nice spot to hang the CW pouch on.

Nightcap is OK with binos, perhaps not dual 14 but a lighter weight real bino body.

The default counterweight velcro placement sucks a bit, too high to get the most out of the weight. Regardless 600 grams of binos are okay, not perfect, but does the job. You may need to modify the fore head padding as it tends to start leave some marks after longer use. Modifying the counterweight placement helps with this too.

I use  a PVS-14 a Rhino II without a counter weight it feels good, but when I run it with a SureFire M1, 2 AA and 3 123A it feels more balanced