crazy weather!

[BillyBob58]

OK, we all know how we have to be cognizant of the cooling effect that going higher into the mountains can have. How when we get our weather history based on towns near to the mountains where we are going to hike, we might need to lower the temp estimates quite a bit to adjust for the several thousand feet of elevation we might gain while hiking near those towns with their long term weather records available to us.

But sometimes it is enough to just be surrounded by steep mountains, rather than up on top of a mountain. IOW, the old temperature inversion, when the air is very calm, and the frigid air on a mountain top, being heavier than warmer air, sinks down into the bottoms. Look at this morning in Wyoming: At Big Sandy Trailhead, 9080 feet, it is about +1F at 0700.
http://www.wrh.noaa.gov/mesowest/get...e=1&banner=off
Over the other side of the Continental Divide, at Hobb's Park at 10,100 ft, it is a balmy 29F!

But at the nearby New Fork River, west of Big Sandy at 6800 feet, it is minus 13F!
http://www.wrh.noaa.gov/mesowest/get...e=1&banner=off

At the little town of Pinedale 6800 ft station, west of Big Sandy, it is minus 4
http://www.wrh.noaa.gov/mesowest/get...e=1&banner=off

On the eastern side of the range, not far from Hobb's Park at 10,100- but down at Bull Lake way down at 5600 feet, it is +5F!

This is not a whole lot of miles between any of these weather stations. But on the west side of the mountains there is a range of +1 at 9080 ft to minus 13 at 6800.

On the east side there is a range of 29F at 10,100 to +5 at 5600 ft! And the colder temps are way lower down. 24* colder nearby at 5000 ft lower elevation!

[breyman]

Weather is such an interesting thing - it always fascinates me. Anyone who has ever camped in a bowl and then up on a nearby ridge has seen this in action.

Over the summer, we had a group of about 20 boy scouts go on a high adventure trip. The older boys decided to camp down next to a small creek in some trees that looked very pretty and serene. The younger boys chose a site up on a ridge near some rocks a hundred yards away and probably 100 feet higher.

We used the backcountry spot as a basecamp to summit a 14er (a 14,000 foot peak nearby) and on the second day it got rainy and much chillier. The younger boys were suddenly feeling much smarter when their camp was a good 10-15* warmer than the older boys lower down. Nothing like those real-world experiences to teach everyone a useful lesson.

[mbiraman]

I think whenever your in the mnts it can be like that. The East and West Kootenays are separated by the Purcell Mnts. Historically there is about a 50-60 Degree(f) difference in winter, the East Kootenays being colder bounded on one side by the rockies.
Calgary Alberta has some of the craziest weather i've ever heard of what with getting the cold of the rockies and prairies and getting regular Chinooks creating 20-30 degree temp swings in a matter of an hr or two.

bill

[BillyBob58]

I think whenever your in the mnts it can be like that. The East and West Kootenays are separated by the Purcell Mnts. Historically there is about a 50-60 Degree(f) difference in winter, the East Kootenays being colder bounded on one side by the rockies.
Calgary Alberta has some of the craziest weather i've ever heard of what with getting the cold of the rockies and prairies and getting regular Chinooks creating 20-30 degree temp swings in a matter of an hr or two.

bill

Good examples!

I started this thread to show how the increasing elevation related temp decreases sometimes work just the opposite of how we expect. And it is not all that infrequent. Stll, normally it works almost exactly as predicted. Of course, sometimes comparing a high mountain weather station to the nearest town, there will be enough distance such that a front or different weather system can complicate matters. One place where that is usually not a factor is the Grand Canyon, where there are only a few "as the crow flies" miles between the top of the Canyon and the bottom. More trail miles than horizontal miles, I may not be wording that right. But draw a line straight up from the canyon bottom to the height of the rim, then measure distance from rim to line, very few miles.

So, this morning on the north rim, at 8134 ft, it is 26F. 5584 ft down the hill, more like a cliff, at 2550 ft, it is 53F, or 27F difference.

Old rule of thumb, for every 1000 ft of elevation change in precipitation, 3.5* change. Clear high pressure weather, 5F change. So, 3.5 to 5F change per thousand feet as I remember it. ( or roughly the equivalent of moving 300 miles north for every 1000 feet)

So 5584 elevation dif / 1000 = 5.584.
27F dif / 5.584 = 4.835*F temp dif per 1000 ft of elevation dif! Though there is a chance of snow increasing for today, there was zero precip this morning or yesterday, so I guess the closest estimate would be the no precip model of 5F per 1000 ft. So looks to me like the actual result of 4.835 works out awfully close to to the rule of thumb.

[HURTHEART]

I thought western Oregon, sitting between two mountain ranges had crazy weather until I moved to Calgary, AB.

[Deadphans]

Weather is pretty neat! I always pay attention to it - not to mention I am a young wildlife biologist and trying to see differences in climate (climate change?).

But it is so cool to play around with micro climates. Or how about how the wind blows off shore during the day, then on shore at night? Neato!