Mt Washington is a great venue to learn and practice mountaineering skills before venturing out to the bigger ranges. Here is a list of gear I recommend taking on a winter Mt. Washington attempt.
Nordwand 6000 High by Mammut — Boots are a very personal decision. I recommend trying them on before you buy them to make sure they are a good fit. I find the La Sportiva and Scarpa mountaineering boots to be too narrow. I am a 10.5 in a medium width and these fit me perfect. They are light, warm, and comfortable.
Petzl Vasak Leverlock Crampons by Petzl — These crampons perform wonderfully and are light weight. Petzl crampons are modular, meaning you can interchange some of the front sections with other models. For example, the heel section on this is the same as the Darts.
Petzl Sum'Tec Adze Ice Axe Black by Petzl — This is the most versatile mountaineering axe. You can self-arrest, swing it, and plunge with it. And it is "T" rated. This is probably over kill for Mt. Washington, but if you are going to buy one mountaineering axe, this is it!
C.A.M.P. Geko Ice Pro Gloves by Camp — These are hands down my favorite gloves for technical winter activities They are the perfect balance between insulation and dexterity. I find the sizing to run normal. I wear XL in most gloves and these XL's fit perfect on me. I put these on at tree line. They provide the warmth but still have the dexterity to be able to do all the things I need to do along the way.
Men's Mythic Ultra Down Jacket by Rab — At just over a pound this is the lightest and best performing parka I have found. Fits true to size. Compresses down pretty small, too.
Men's Latok GORE-TEX Pro Jacket by Rab — This thing is a fortress! I am usually putting this on to keep the wind out. It is an incredible feeling when the wind is pusing on you with such ferocity, but nothing gets through. I am not an astronaut, but I feel like one up there.
Eiger Nordwand Pro HS Pants Men by Mammut — I wear these with a pair of merino leggings underneath. If I over heat, the 7/8 length zippers offer great ventilation. If I get cold, I slip my Rab Mythic Down Shorts on underneath.
Men's Mythic Down Shorts by Rab — Honestly, I like puffy shorts. If you have these on over your longjohns and under your goretex pants, they add so much warmth. I can also get these on (under my goretex pants) with out taking them or my boots off! This is the best solution to the delema of lower body layers.
Alti II GORE-TEX Mitten by Outdoor Research — This is mandatory gear in the winter on Mt. Washington. When the mercury drops and the wind is howling, you need to protect your hands. These things are a furnace. They do run large, so go one size down. I usually wear XL in gloves, but the L fits much better.
Ignik Toe Warmers - Multipack 10 Pair by Ignik — I use these in my gloves sometimes. It's my little trick. Handwarmers are too big to fit in most gloves. Plus these are stick, so they stay put better. They are also lighter and cheaper than handwarmers. Make sure you activate them by shaking and letting them "breathe" before you put them in your gloves.
Ignik Multi-Use XL Warmers - 24 Hr. Multipack 4 Pair by Ignik — This is another good insurance policy against the cold. Place these near your core if needed.
Stanley Classic Legendary Vacuum Bottle - 1 qt. by Stanley — Your water bottle will freeze. Get one or 2 of these. Fill it with a got drink--I recommend hot Gatorade for the calories and electrolytes. It is a bottle of happiness.
Superlite 2-Person Shelter by Rab — Those emergency bivies are pretty worthless. I refer to this contraption as a "Bothy Bag." It's basically an instant tent. They make them in different sizes, but the idea is you open it up and have people sit in it and it creates a micro climate. The thing blocks out the elements and warms up real fast. Imagine being high up on Washington in full conditions and a member of your group goes down. You will want one of these. Sorry for the nightmare fuel.
Therm-a-Rest Z Lite Sol Sleeping Pad by Therm-a-Rest — In the event someone in your group goes down, you need to insulate them from the ground otherwise hypothermia will set in quickly. This thing can't deflate. Mine has lasted me over a decade.
Cascade Classic by Smith Optics — Bring 2 pairs of goggles. I like the clear goggles for Mt. Washington because it usually has high wind and cloudy skis. You can bring one clear and one tinted, but definitely 2. If your goggles fog up on a really windy day, that is a bad situation.
Transfer Goggles by Smith Optics — This is a good Tinted pair of goggles for Mt. Washington.