Franconia Notch Question. Help me out!

[murph]

Somebody has to know the answer to this question. I have been riding up north now for about 3 or 4 years after several years around the lake. It seems like every single time i go up north Franconia Notch is beautiful until you hit the bridge and start heading toward twin mountain. please, anyone, how come there is NEVER snow after you pass cannon mountain? I went there yesterday and the only snow on the ground at all was the dusting they got up there the other night. Somebody help me out!

[VitaBene]

Somebody has to know the answer to this question. I have been riding up north now for about 3 or 4 years after several years around the lake. It seems like every single time i go up north Franconia Notch is beautiful until you hit the bridge and start heading toward twin mountain. please, anyone, how come there is NEVER snow after you pass cannon mountain? I went there yesterday and the only snow on the ground at all was the dusting they got up there the other night. Somebody help me out!

Murph. We just came back from Bretton and noticed the same thing and have in years past as well. It only lasts a few miles or so then picks up again.

Maybe Don can move this to weather forum- those folks will chime in

[Rose]

Precipitation shadow (http://en.wikipedia.org/wiki/Rain_shadow)

There are several papers available online (http://www.google.com/search?q=precipitation+shadow&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a) for those who want to read more about it.

[murph]

thanks rose! that explains it.

[chipj29]

I think it is a combo of what Rose posted about, and wind. The wind seems to constantly scream through the notch, which acts to blow both the falling snow and the snow on the ground out of the notch. I noticed that exact effect last week when I drove through there. You could see the snow "dunes" from the wind.

[fatlazyless]

Up north of the notch, all it snowed last storm was 8", while Meredith got 14". Storm before that, up north just got a light dust'n and Meredith got about ten inches.


"The answer is a-blow'n in the wind." Bob Dylan 1965


North of the notches is like a very different place from the hustle-bustle of the lakes region.

[jmen24]

I have a quick question regarding the shadow theory. Are the mountains in the northeast really tall enough to cause this? I know that we are tall enough for a wringing affect to occur but I question the height to block precip. Having stood atop Cannon during a many a storm, it is my observation that the clouds advance over without to much stalling. Now, my second observation of the weather at the notch is that when it is raining to the south of the notch it is usually snowing to the north on the mountain itself, which is consistant with the wringing affect that has been mentioned as well as the drying shadow effect but the precip continues over. I do not have an answer for why there is no snow on the trails past the notch but these are my observations living and playing in the northcountry my entire life. Having been atop mountains that far surpass the height of our mountains here you see substaintial differances in weather changes at altitude, we get some but nothing compaired to other ranges. We do have unique weather here though so I am open to a lesson from someone in the know.

[SIKSUKR]

Hey Chip, I'm the guy to ask as I've been at Cannon since the late 70's. I've watched the crazy difference in weather conditions for many a moon. First, Cannon gets a much higher melt than most areas because of it's topography. When winter storms go to the west of the Franconia range, the south wind will blow up the notch. Because the notch rises 1000 ft and has very high walls on each side, the wind has to compress as it makes it way to Cannon. By the time it gets to the top the winds can easily be twice that of the Lincoln area. At least 3 times a season my house at Mittersill feels like the roof is about to blow off with these systems. With this wind brings much higher temps at Cannon. It's not uncomman to have a 10 degree higher temp than in Lincoln. I've seen this happen uncountable times in my 30 + years living at Cannon in the winter. Second,the terrain north of Cannon drops sharply down in elevation to Franconia and this had a big drying effect on any system. It simply does not snow as much right at Cannon vs just 3 miles south in the notch. Even nor'easters are not kind to Cannon. We actually can end up with better snowfall than other close ski areas from small Alberta clippers that come from the west. The opposite can be true also in that small disturbances will hang right over Cannon and put out snow when its not snowing at all at Loon.Yesterday was a classic example. It was snowing lightly all day at Cannon. I left to head south and there was not a cloud in site from Loon south. The notch creates it's own little micro climate that's amazed me for decades. The 2 biggest factors though in answering your question are that Cannon simply gets much bigger melts and the snow shuts down pretty dramatically right at the top of the notch. :(

[no-engine]

Climatological phenomonons.

Find an experienced meteorlogist/climatologist.
If professors formerly from Burke were around, Bill Hovey, be great.
The great Don Kent, retired from Boston TV/Radio, and I think lives in Sanbornton.

They'd be able to send one to great sources.

The weather always changes north of the notches, by my observations also.

[SIKSUKR]

I actually won a beer bet with another Lyndon State College grad Tim Kelly from NECN. Him and Joe Joyce (also LSC grad) were at the Cannon bar a few years back after coming to my house for a few beers. Tim gave his estimate on an upcoming storm and I gave him the nay nay not here. The storm was headed west of us and I explained the same scenerios as in my last post. He did not forget when he came back to Cannon a month later and paid me in full. I think I gave him a little locals insight.

[Rattlesnake Guy]

As air moves up and over a mountain, the temperature drops 5.5 degrees for every 1000 feet of rise. The water vapor in the air condenses at the lower temperature and precipitates on the mountain and notch below. As the air comes back down the other side, the air warms 5.5 degrees per 1000 feet and has an increased capacity to hold onto it's moisture. Sort of like squeezing moisture out of a damp towel. The towel that was just dripping while squeezing is now drier and not likely to drip.

[SIKSUKR]

RG is correct in that rising air cools and condenses and is the reason you'll see mountain areas that just seem to "grow" clouds as if they are not coming from anywhere. However, I've witnessed countless times on my winter weekly trek through Franconia Notch the temperature increase 8-10 degrees when a south wind in blowing up the notch. Believe me, I've watched this for 30+ years of driving through FN every winter weekend.