summit temp.

[skiseason]

Does anyone know about how much colder it is on the summit than it is in the town of Wilmington? Basically, just wondering if the temps will be cold enough to blow snow every day from now til' new years.

[highpeaksdrifter]

Does anyone know about how much colder it is on the summit than it is in the town of Wilmington? Basically, just wondering if the temps will be cold enough to blow snow every day from now til' new years.

I’m not a meteorologist by any stretch, but I know there are a lot of factors involved. Sometimes there is a temperature inversion and it is colder at the base then the summit. Speculating completely unscientifically I would guess on average the summit is 6 to 10 degrees colder then the base.

[cloudspin]

One can get a general idea by reference to the Mt. Washington observatory site <www>. There is a temp profile for the auto road. In general, there is about a 20 degree difference between the base there ~1,600 and the summit at 6,288. There are intermediate remote sites all the way up, so it is something of a guidepost for you. Hope that helps.

[ajl50]

depending on humidity air temp drops 3-5 degrees per 1k of elevation gain. However night time cooling changes this. Valleys are often cooler at night for two reasons. First cold air sinks into the valleys and second the valleys lose the sun sooner. Therefore if the low at the base is 10 you can't assume that at the summit is colder. Also inversion is very very common in the northeast this time of year. That means that warm air moves in at mid levels (5-10k) and therefore you can warm air at the summit that traps cold air below it.

[NPN]

Or, on a daily basis, you can call the snowphone, and they will give you the exact temps for the base, mid, and summit at the start of the day.

Granted, as you've read from the other posts in this thread, there are a number of variables that may change that breakdown throughout the day, but, at least, it's a concrete start.

depending on humidity air temp drops 3-5 degrees per 1k of elevation gain. However night time cooling changes this. Valleys are often cooler at night for two reasons. First cold air sinks into the valleys and second the valleys lose the sun sooner. Therefore if the low at the base is 10 you can't assume that at the summit is colder. Also inversion is very very common in the northeast this time of year. That means that warm air moves in at mid levels (5-10k) and therefore you can warm air at the summit that traps cold air below it.

If your are not a weather person, you missed your calling. I thought I was a freak about the weather! It sounds like your are almost a freak geak. Can you do a snow dance for us and get us a blizzard?
Happy Holidays

[ajl50]

I'm a general geek. My problem is all my junk knowledge hasn't helped me yet in law school.
I've liked weather since the blizzard of 1996 and I won 20 dollars off my dad for betting him it would snow more than 12 inches. ( still have never been paid)

Actually I've been snow dancing like crazy and shutting my mouth cause things are actually starting to look positive for placid after this weekend.

[KT22]

I'm a general geek. My problem is all my junk knowledge hasn't helped me yet in law school.
I've liked weather since the blizzard of 1996 and I won 20 dollars off my dad for betting him it would snow more than 12 inches. ( still have never been paid)

Actually I've been snow dancing like crazy and shutting my mouth cause things are actually starting to look positive for placid after this weekend.

Do you ever use the NAO forcasts from NOAA to keep track of the weather? I've started looking at these last week after reading about the effects of El Nino on Northeastern weather and how the current El Nino makes NAO- less likely. The way I understand it is that NAO+ keeps the Jet Stream North and NAO- pulls the Jet Stream (and the cold artic air) South. You seem fairly knowledgeable about weather, I was just wondering how useful these forcasts are.

check out this graph of the NAO index for the last several months. Its seems to correlate well with the temperatures we've seen.

http://www.cpc.noaa.gov/products/pre...nao_index.html

[ajl50]

The NAO represents two things in my mind. 1- blokcing high pressure that holds cold air, in the form of a trof, over the northeast. Examples are the last three weeks of october and the first three weeks of December 05. The NAO also represents storm tracks. When the NAO changes - neg to pos or pos to neg we, in the northeast tend to see more storms along the coast.
It's not great however for determining the extent of the weather. When there is a pac jet that is powerful and a gulf of alaska low that pulls the northern branch of the jet stream north, there just isn't that much cold air to pull in and hold. That's the problem we have now. The air that comes in just isn't that cold. Canada isn't that cold. ALL the cold air is stuck over the pole and siberia. It has been migrating towards us but don't look for nasty winter weather until the middle of jan.
That doesn't mean the 'dacks will not see snow. Actually I think that the nex three weeks will be a snowier(anything is snowier than the last three weeks) period but with above normal temperatures because even with a neutral to negative NAO the air being blocked isn't really cold arctic air.

[KT22]

You really know your stuff. I guess you’re right about there not being very cold air in Canada. I think I assumed there was always frigid air North of the border due to Don Cherry’s blustery personality.

At any rate, I think we all deserve a good 24” lake effect dump pretty soon.