View Full Version : Mountain Point Forecast Accuracy (Are mountains warmer than the valley at night?)
ArvinSmee
09-17-2018, 11:47
Do any of you use Mountain Point Forecasts (https://www.weather.gov/btv/mountain)? I'm planning a trip in the Adirondacks that might involve camping at 4000', so I wanted to get a good idea of the cold we might expect. I've been keeping track of the forecasts for Marcy and I've realized that often the low on the mountain is often higher than the low in the city, ~3800' below. How is that possible?
Here's the last few days of data I've collected:
Marcy Forecast (5344') (https://www.weather.gov/btv/mountain_enhanced?loc=MOUNT%20MARCY)Saranac Lake Reported (1545') (http://w2.weather.gov/climate/index.php?wfo=btv)Difference12 55 / 50 62 / 52 -7 / -2
13 60 / 52 79 / 46 -19 / +6
14 58 / 51 80 / 42 -22 / +9
15 63 / 52 83 / 49 -20 / +3
16 62 / 53 83 / 54 -21 / -1
It looks like the high is typically ~20 degrees cooler, and the low is about the same or a few degrees warmer. I have no reason to not trust the Mountain Point Forecasts, but this goes against everything I've ever read, which states that you loose about 3.3 degrees per 1000 feet, with no difference between night and day. Theoretically, the temperatures on Marcy should be about 13 degrees less than Saranac Lake.
Anyone have any idea what's going on on here?
ArvinSmee
09-17-2018, 11:52
43659
attached a screen shot since the formatting got messed up.
DuneElliot
09-17-2018, 11:54
Do any of you use Mountain Point Forecasts (https://www.weather.gov/btv/mountain)? I'm planning a trip in the Adirondacks that might involve camping at 4000', so I wanted to get a good idea of the cold we might expect. I've been keeping track of the forecasts for Marcy and I've realized that often the low on the mountain is often higher than the low in the city, ~3800' below. How is that possible?
Here's the last few days of data I've collected:
Marcy Forecast (5344') (https://www.weather.gov/btv/mountain_enhanced?loc=MOUNT%20MARCY)Saranac Lake Reported (1545') (http://w2.weather.gov/climate/index.php?wfo=btv)Difference12 55 / 50 62 / 52 -7 / -2
13 60 / 52 79 / 46 -19 / +6
14 58 / 51 80 / 42 -22 / +9
15 63 / 52 83 / 49 -20 / +3
16 62 / 53 83 / 54 -21 / -1
It looks like the high is typically ~20 degrees cooler, and the low is about the same or a few degrees warmer. I have no reason to not trust the Mountain Point Forecasts, but this goes against everything I've ever read, which states that you loose about 3.3 degrees per 1000 feet, with no difference between night and day. Theoretically, the temperatures on Marcy should be about 13 degrees less than Saranac Lake.
Anyone have any idea what's going on on here?
It's called inversion...the coldest air sinks into the valleys at night and the warmer air stays higher up. I used to live at 5200ft in the foothills. It was always at least 10* warmer, and often 15-20* warmer, there than 20 miles away and 1500ft down in the valley where I worked. The biggest difference was one January when it was 65* at my house and 25* at work...crazy
ArvinSmee
09-17-2018, 11:54
seems like i posted the same image three times but you can't edit your posts on this forum for some reason.
HooKooDooKu
09-17-2018, 12:23
seems like i posted the same image three times but you can't edit your posts on this forum for some reason.
You'll notice there isn't much commercial advertising on this web site. It seems to be mostly supported by "contributing members (https://whiteblaze.net/forum/payments.php)".
One of the benefits of being a contributing member is the ability to edit your posts.
Slo-go'en
09-17-2018, 14:27
When I was winter caretake at Gray Knob at 4500 feet, early in the morning it would often be -30 in the valley but only -20 up at the cabin. I was glad I wasn't in the Valley :)
This is usually only very early in the morning when the cold air has settled into the valley floor and there is little wind to move the air around.
ArvinSmee
09-17-2018, 15:24
so it's called inversion... good to know. i guess i can trust the mountain point forecast! this is great news, i was expecting that we'd have to be ready for 20 degree lows, instead, it looks like we should be prepared for something closer 50. that's huge!
Inversion is not the normal relationship between elevation change and temperature.
“Although the actual atmospheric lapse rate varies, under normal atmospheric conditions the average atmospheric lapse rate results in a temperature decrease of 3.5°F/1,000 ft (6.4°C/km) of altitude.Feb 24, 2013”
Be warm. Be safe.
Wayne
the top of the mountain is closer to the sun during the day - but at night when the sun is on the other side of the earth, it is farther from the sun so colder
Time Zone
09-23-2018, 15:39
the top of the mountain is closer to the sun during the day - but at night when the sun is on the other side of the earth, it is farther from the sun so colder
I think it's a lot more complicated than distance from the sun. Mercury is far colder than earth during their night, yet it's much closer to the sun than we are.
DuneElliot
09-23-2018, 15:40
the top of the mountain is closer to the sun during the day - but at night when the sun is on the other side of the earth, it is farther from the sun so colder
While it sounds logical, that is not how anything works
come on now, go with the flow - just like the anti evolutionists claim the dinosaurs are deeper because they are heavy and sunk........
BTW, as I will be on the trail April 1 so I need to get some leg pulling in the bank, so to speak
I think it's a lot more complicated than distance from the sun. Mercury is far colder than earth during their night, yet it's much closer to the sun than we are.
While it sounds logical, that is not how anything works
2 victims, should I have waited longer for more?
DownYonder
09-23-2018, 20:00
the top of the mountain is closer to the sun during the day - but at night when the sun is on the other side of the earth, it is farther from the sun so colder
Is that also why you burn easier at altitude :-?
Is that also why you burn easier at altitude :-?
and down low ( closer to the sun and hell )
Time Zone
09-23-2018, 20:06
come on now, go with the flow
I think you are seeing flow where there was none, at least, none in the direction you took it.
the top of the mountain is closer to the sun during the day - but at night when the sun is on the other side of the earth, it is farther from the sun so colder
Is that you Ken M? Lol