Pinkham Window

[forestgnome]

I learned of Pinkham Window while snowboarding at Wildcat many years ago, when I commented on the phenomenon to a patroller who identified it. It's a hole in thick cloud cover that just hangs over the notch. Both Wildcat Ridge and the Presidentials are socked in, but the hole remains. In the afternoon, the sun shines through and directly hits the slopes while snow lightly falls. I've experienced this several times over the years.

So, in meteorological speak, what's going on?

[Brad]

I learned of Pinkham Window while snowboarding at Wildcat many years ago, when I commented on the phenomenon to a patroller who identified it. It's a hole in thick cloud cover that just hangs over the notch. Both Wildcat Ridge and the Presidentials are socked in, but the hole remains. In the afternoon, the sun shines through and directly hits the slopes while snow lightly falls. I've experienced this several times over the years.

So, in meteorological speak, what's going on?

The Gods are with you.

[Bill O]

Its descending air. On the windward side of the mountain the air is rising and cooling to form clouds. On the leeward side (Pinkham) the air is sinking and the clouds are evaporating.

[Mike D]

This very phenomenon is why Twin Mountain is the snowmobile capitol of New Hampshire, while Attitash spends hundreds of thousands of dollars a year on snowmaking.

Bill, do you know where to find stats on sunshine minutes/hours/days for towns on either side of the Whites? I'd wager that Conway has twice as many sunny days as Twin Mountain.

[HikerBob]

Cloudwatching is facinating and the new time lapse movies from the web cams offer a whole new perspective on cloud formation and dispersal.

Bob

[Bill O]

This very phenomenon is why Twin Mountain is the snowmobile capitol of New Hampshire, while Attitash spends hundreds of thousands of dollars a year on snowmaking.

Bill, do you know where to find stats on sunshine minutes/hours/days for towns on either side of the Whites? I'd wager that Conway has twice as many sunny days as Twin Mountain.

I don't think there is anything official, there just aren't enough weather observers out there. Sunshine minutes data is typically only recorded at airports, but not always. Co-op observers don't really deal with that kind of data either. You may want to play around on the NCDC website, but you'll quickly find how frustratingly inconvenient it is.

[afmrintern]

Looks like the Pinkham window effect is this morning. Brad, stole this from your website!

[Mike D]

This very phenomenon is why Twin Mountain is the snowmobile capitol of New Hampshire, while Attitash spends hundreds of thousands of dollars a year on snowmaking.

We will be able to see this firsthand once the Presidential Cam goes online; there will be times when the Ravines Cam will be clear while the Pres view will be foggy.

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