January 15, 2005, Hatchery Creek weird stuff
1/15/05
6419
11
Sketchy avy conditions meant a low angle safe tour, so we tried for Big Jim mountain, not really expecting to summit (looks like there is avy terrain near the summit). We ended up making it to the ridgeline around 6300ft, where my friend's dogs were too exhausted to continue.
The snow conditions were generally good, though there is very little snow cover. Enough above 5000ft or so, where there is no underbrush. Sections exposed to winds had hard slabs. Heard a whoomph maybe once. Didn't dig any pits, since we didn't travel through anything steep enough to slide. In places sheltered from the wind (which is most places on this tour), the snow seemed to have a favourable density profile (lighter on top, gradually getting denser). Snowdepth was variable... 1-2 feet at 4500ft, and maybe 2 to 3 feet at 6000ft.
The first 2000ft of this trail switchbacks up through dense forest with thin snowcover, although there was a steep open section with deep enough snow cover to make for some nice turns in light powder, but still enough brush to limit avy danger.
Now for the weird stuff. Clockwise from the Chiwawa river valley to the Stuart Range, above a lower cloud deck, there was some kind of "lens" that was "smearing" the view of the mountains, stretching them out vertically, like a TV scan line repeating itself. It looked like this:
Here is another one:
http://www.mtnphil.com/Temp/Lens2.jpg
Very cool - I've never seen anything like it. We postulated about its cause, until we encountered something very strange where we were, and presumed we must have climbed into it in our location. Over the course of maybe 200 yards horizontally, and 100ft vertically, as we climbed, the temperature changed from bone-chilling "put-down-jacket-on-immediately-if-you-stop" cold, to "unzip-jacket-and-take-off-hat-for-5-minutes-and-still-don't-get-cold" warm. I've never experienced such an extreme temperature change over such a small distance. It was like walking from the Arctic to the tropics (well maybe not quite). We guessed the temp changed from 10 degrees to 25 degrees over 100ft.
I just checked out the Mission Ridge telemetry for today, and I see something pretty similar.. at 2 o'clock it was 9 degrees at 5300ft and 25 degrees at 6740ft. Our temperature change occured from 6200ft to 6300ft.
And the other weird thing was the trees cracking on the descent, maybe around 5500ft. I've heard a tree crack and pop here and there, but this was like the climax of a bag of popcorn. A symphony of pops - I've never heard anything like it before. I guess there were undergoing extreme warming maybe? It was only occuring over a very narrow slice of elevation.
The descent down the narrow trail was positively frigid - had to stop an warm my face up every few minutes.
The drive back over Stevens Pass was not too bad, but between Skykomish and Sultan the road was horrible - black ice with blowing snow and high winds. Took about 45 minutes to get from Index to Sultan.
The snow conditions were generally good, though there is very little snow cover. Enough above 5000ft or so, where there is no underbrush. Sections exposed to winds had hard slabs. Heard a whoomph maybe once. Didn't dig any pits, since we didn't travel through anything steep enough to slide. In places sheltered from the wind (which is most places on this tour), the snow seemed to have a favourable density profile (lighter on top, gradually getting denser). Snowdepth was variable... 1-2 feet at 4500ft, and maybe 2 to 3 feet at 6000ft.
The first 2000ft of this trail switchbacks up through dense forest with thin snowcover, although there was a steep open section with deep enough snow cover to make for some nice turns in light powder, but still enough brush to limit avy danger.
Now for the weird stuff. Clockwise from the Chiwawa river valley to the Stuart Range, above a lower cloud deck, there was some kind of "lens" that was "smearing" the view of the mountains, stretching them out vertically, like a TV scan line repeating itself. It looked like this:
Here is another one:
http://www.mtnphil.com/Temp/Lens2.jpg
Very cool - I've never seen anything like it. We postulated about its cause, until we encountered something very strange where we were, and presumed we must have climbed into it in our location. Over the course of maybe 200 yards horizontally, and 100ft vertically, as we climbed, the temperature changed from bone-chilling "put-down-jacket-on-immediately-if-you-stop" cold, to "unzip-jacket-and-take-off-hat-for-5-minutes-and-still-don't-get-cold" warm. I've never experienced such an extreme temperature change over such a small distance. It was like walking from the Arctic to the tropics (well maybe not quite). We guessed the temp changed from 10 degrees to 25 degrees over 100ft.
I just checked out the Mission Ridge telemetry for today, and I see something pretty similar.. at 2 o'clock it was 9 degrees at 5300ft and 25 degrees at 6740ft. Our temperature change occured from 6200ft to 6300ft.
And the other weird thing was the trees cracking on the descent, maybe around 5500ft. I've heard a tree crack and pop here and there, but this was like the climax of a bag of popcorn. A symphony of pops - I've never heard anything like it before. I guess there were undergoing extreme warming maybe? It was only occuring over a very narrow slice of elevation.
The descent down the narrow trail was positively frigid - had to stop an warm my face up every few minutes.
The drive back over Stevens Pass was not too bad, but between Skykomish and Sultan the road was horrible - black ice with blowing snow and high winds. Took about 45 minutes to get from Index to Sultan.
That's a bizzarre light effect. Cool!
Now for the weird stuff. Clockwise from the Chiwawa river valley to the Stuart Range, above a lower cloud deck, there was some kind of "lens" that was "smearing" the view of the mountains, stretching them out vertically, like a TV scan line repeating itself.
On 3 Feb 1996 I skied Jim Hill Mountain with some friends and saw a similar phenomenon. Here's how I described it in my journal:
"Saw intriguing mirage caused by the dome of cold air settled over eastern Washington (top about 5000 feet). Created illusion of mesas and even floating mountains as we looked east from above the cold/warm interface. Warm front clouds were starting to override from the west."
So it seems like this should be a predictable phenomenon when you have really cold air in eastern Washington and a warm front starts to override it.
Interesting... actually, I first noticed it looking to the northeast, and it *really* did look like mesas... I was like "hmm... I didn't know we had that kind of terrain in washington". Then only when we got a better view of the Maude/Entiat area did we realize what it was.
Some more mesas:
Another strange thing we experienced was a pronounced echo on the ridge top at 6200ft. I assume it was from the trees scattered around the edge of the meadow, but I've never heard such a strong echo from trees - when we talked it was like we were in a big cavern. The lack of wind maybe helped the effect.
I guess it was a good day for odd natural phenomena....
Some more mesas:
Another strange thing we experienced was a pronounced echo on the ridge top at 6200ft. I assume it was from the trees scattered around the edge of the meadow, but I've never heard such a strong echo from trees - when we talked it was like we were in a big cavern. The lack of wind maybe helped the effect.
I guess it was a good day for odd natural phenomena....
Very cool Phil! I love this kind of stuff. The explanation is actually quite simple for this and is a reverted mirage from the typical ones you see on the road where the cold air is on top of the warm air.
Here is a website that gives a good explanation on this:
Now for the weird stuff. Clockwise from the Chiwawa river valley to the Stuart Range, above a lower cloud deck, there was some kind of "lens" that was "smearing" the view of the mountains, stretching them out vertically , like a TV scan line repeating itself.
Here is a website that gives a good explanation on this:
Now for the weird stuff. Clockwise from the Chiwawa river valley to the Stuart Range, above a lower cloud deck, there was some kind of "lens" that was "smearing" the view of the mountains, stretching them out vertically , like a TV scan line repeating itself.
I once saw a similar phenomena once several years ago looking at the Olympics from somewhere in the Cascades. I can't find any notes on it. As I recall it was winter and several of the Olympics peaks had images of themselves floating directly above. I even remember that each image seemed sort of upside down. Is this possible? Guess I'll go read the link given by Michael.
This is really interesting - thanks for the report and photos, Phil. I had never heard of this before, but can see how it is analogous to the mirages over a hot road or sand. The temperature differences which led to this phenomenon can be seen in the NWAC telemetry data, along with some amazing temperature swings. Good examples on the Stevens Pass pages.
From the Stevens Hwy2 page (OSOSTS), hourly temperatures on 1/16 from 3 am to 7 am:
4000' temp: 10, 11, 10, 11, 10
4900' temp: 7, 8, 29, 28, 32
From the Stevens Ski Area page (OSOSK9), hourly temperatures on 1/15 11pm to 1/16 2am:
5240' temp: 8, 18, 24, 29
5400' temp: 3, 4, 5, 6
Warm air overriding the cold, except that the 5400' station (Tye Mill Chair) remained in cold air?
The Alpental page (OSOALP) is pretty interesting too. Overnight and into today, the 5400' station climbed slowly from 13 to 33 degrees. The 3120' station climbed slowly from 12 degrees to 22 degrees. The mid-level, 4300' station, however, went through this progression over the same time period: 5 to 19 to 12 to 40 to 23 to 45 to 20 to 44 to 28 to 40.
Other stations that get east-side influence, like the White Pass, Snoqualmie Pass, and Mission Ridge stations showed similar wierd stuff going on. What a great place this is - even when the snow sucks!
From the Stevens Hwy2 page (OSOSTS), hourly temperatures on 1/16 from 3 am to 7 am:
4000' temp: 10, 11, 10, 11, 10
4900' temp: 7, 8, 29, 28, 32
From the Stevens Ski Area page (OSOSK9), hourly temperatures on 1/15 11pm to 1/16 2am:
5240' temp: 8, 18, 24, 29
5400' temp: 3, 4, 5, 6
Warm air overriding the cold, except that the 5400' station (Tye Mill Chair) remained in cold air?
The Alpental page (OSOALP) is pretty interesting too. Overnight and into today, the 5400' station climbed slowly from 13 to 33 degrees. The 3120' station climbed slowly from 12 degrees to 22 degrees. The mid-level, 4300' station, however, went through this progression over the same time period: 5 to 19 to 12 to 40 to 23 to 45 to 20 to 44 to 28 to 40.
Other stations that get east-side influence, like the White Pass, Snoqualmie Pass, and Mission Ridge stations showed similar wierd stuff going on. What a great place this is - even when the snow sucks!
The Alpental page (OSOALP) is pretty interesting too. Overnight and into today, the 5400' station climbed slowly from 13 to 33 degrees. The 3120' station climbed slowly from 12 degrees to 22 degrees. The mid-level, 4300' station, however, went through this progression over the same time period: 5 to 19 to 12 to 40 to 23 to 45 to 20 to 44 to 28 to 40.
The mirage photos are very cool, as are the various sudden temperature swings. But the Alpental 4300' temp sensor is just flaky, it has been having random 20-40 degree jumps for the past few weeks despite the stable cold weather (check the past 10 days archived data before it's gone). So that weird progression is unlikely to be real.
I think the progression at Stevens is real though. The was really warm air aloft (look at Baker and Paradise telemetry) and cold air at the surface and trapped in Eastern Washington. At the passes, cold air from the east kept the surface below freezing, but allowed the air aloft to warm, and hence freezing rain.
Stevens trail maps:
http://www.stevenspass.com/html/mountaininfo/mountainmap.shtml#
In this sort of situation, the temperature at the passes will be locally extremely variable depending on wind. I suspect at Stevens, cold air comes up the backside and flows through the pass at the top of Tye Mill/Double Diamond, then sinks past the Daisy chair (4300). Skyline must be relatively protected from the cold air. Grace Lakes is tucked somewhere behind Cowboy Mtn/Skyline chair, and I've noticed it can be a few degrees warmer than the other sites becauses it gets less cold air from the east. Has anyone who skis at Stevens a lot seen this or something similar?
I've seen a similar thing happen at Snoqualmie. Cold air flows up to Alpental from the interstate than escapes over the tiny pass at the top of the quad and over the divide above Source Lake to the warm Middle Fork. I wouldn't doubt that the temperature at the top of the quad (4300 ft, if this is where the telemetry is?) could shift wildly if the wind were switching direction, but I agree with you Amar that it is hard to know since the temperature sensor is broken. There are some interesting wind shifts at the pass too - look at the wind directions on the Snoqualmie summit site and at the top of Alpental. All easterly at the summit, but Alpental shifts from east to west to east again.
Stevens trail maps:
http://www.stevenspass.com/html/mountaininfo/mountainmap.shtml#
In this sort of situation, the temperature at the passes will be locally extremely variable depending on wind. I suspect at Stevens, cold air comes up the backside and flows through the pass at the top of Tye Mill/Double Diamond, then sinks past the Daisy chair (4300). Skyline must be relatively protected from the cold air. Grace Lakes is tucked somewhere behind Cowboy Mtn/Skyline chair, and I've noticed it can be a few degrees warmer than the other sites becauses it gets less cold air from the east. Has anyone who skis at Stevens a lot seen this or something similar?
I've seen a similar thing happen at Snoqualmie. Cold air flows up to Alpental from the interstate than escapes over the tiny pass at the top of the quad and over the divide above Source Lake to the warm Middle Fork. I wouldn't doubt that the temperature at the top of the quad (4300 ft, if this is where the telemetry is?) could shift wildly if the wind were switching direction, but I agree with you Amar that it is hard to know since the temperature sensor is broken. There are some interesting wind shifts at the pass too - look at the wind directions on the Snoqualmie summit site and at the top of Alpental. All easterly at the summit, but Alpental shifts from east to west to east again.
Amar is right that the 4300' temp at Alpental is erratic and we should have put a reminder at the top of the NWAC data file some time ago. We will do it today. The weather station is at the bottom of chair 2.
I've seen the same thing you've described, Garth, looking in winter towards the Oly's. At the top of an inversion the Olympics appeared upside down as mesas riding on the top of narrow pillars. Oh wait....maybe I was high at the time. ;)
Yep, it looks you all are right about the Alpental 4300' readings. The strange thing is I wondered about that and so I randomly clicked one of the 10-day archives, and it looked very consistent. It appears that if I had chosen just about any other archived page I would have seen that erratic pattern.
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