GeezerHiker

February 8, 2013

Hot air Mass

Filed under: Hiking, North Cascades, Weather — Tags: — geezerwriter @ 1:30 pm

Yesterday the Senior Trailblazers took our weekly hike, this time to Gates Overlook in the Chuckanut Mountains. In addition to covering almost 2000 feet of elevation change there was a front coming through, so we encountered a broad range of weather as day went on – fog, drizzle, snow flurries and brilliant sunshine. My pictures were pretty poor but I’ll include a few to make the post look more interesting. But the main impetus for my current bloviation was something I read in another blog.

Mass-information

In my last posting I included a link to the Cliff Mass Weather Blog, since he is generally considered to be the Go-to Guy for weather around here. I am starting to regret that after reading his most recent post, where he made a really stupid comment.

Finally, the meteorological honor of Seattle citizens is at stake. Atlantic Monthly has called us “weather wussies” because we are sensitive to a little snow. Let them check out our hills or the ice that tends to develop after light snow. Consider that East Coast types, such as the Atlantic editorial staff, give names like “Storm of the Century” and “Perfect Storm” to events that would invoke a tepid shrug from a Northwesterner. We know who the real weather wimps are.

A cascade along Fragrance Lake Road

A cascade along Fragrance Lake Road

Can he really think that there are no hills or ice east of the Cascades? And is he really sneering at the tornados, blizzards and hurricanes that occur every year elsewhere in the country when he has to dredge up fifty year old storms like the “Columbus Day Storm” to get a decent example of inclement weather? Is he saying that a city that vilifies and throws away a perfectly good mayor because he didn’t show adequate deference to the city’s courage in facing a modest snowstorm deserves to call anyone a “weather wimp”?

No, that would be too outrageous for words. So I choose to assume that he was just kidding, and is not really an ignoramus. Maybe a bit provincial, maybe a little juvenile, but not an ignoramus. And he does seem to know a thing or two about meteorological processes so I won’t ashcan his bookmark just yet. [I left a comment on the blog – I’ll be interested to see if it is approved. It has only been a couple of hours – I’ll update when and if it appears.]

Trees and Weather

I love living in the Pacific NW, where we have been for the last 13 years, and would not gladly move anywhere else. But one of the main reasons is that the weather is so incredibly mild. One a fairly typical day recently, in the middle of “winter”, the temperature swung wildly all the way from 39 to 40 degrees! As a general rule the best way to forecast the weather for tomorrow is to look out the window today. On our hike yesterday we encountered drizzle, snow and bright sunshine, but we had to climb to 2000′ above sea level for that – in town they had mild sunny weather all day.

And I love the fact that snow is available throughout the year, but not in my driveway!

Another grand "view" - just trees in the fog

Another grand “view”

Of course everyone wants to believe that one’s own experiences are the toughest anyone has ever faced, and faulty memory can gild one’s lily (“Why when I was a pup, we walked to school fifteen miles in 40 below, dadgummit!”) but seriously, folks, even a tiny garden-variety tornado is probably more intense than anything the NW has ever seen.

The one thing that is not mild here is the wind and that may help explain why NW natives can convince themselves that the weather here is harsh. We get frequent windstorms that blow trees down left and right – we find fresh “blow-down” on almost every hiking trail in almost every winter. And that is not something I remember seeing much of before I moved out here – a big ice storm might break branches off trees, but a huge, mature tree just toppling over is not a common sight most places.

But I think that may have more to do with the nature of the trees than with the strength of the wind. Most of the trees that topple are big cedars, hemlocks and firs that have very shallow root systems, lacking the big tap root that most trees drive deep into the ground to serve as an anchor. The geology does not permit such deep roots, since in most places other than broad river valleys there is only a thin layer of soil over the bedrock.

On yesterday’s hike down the Fragrance Lake Trail in the Chuckanut Mountains south of Bellingham, as I was thinking about writing this posting, we came across an almost perfect illustration of this phenomenon.

a root plate

A root “plate”

(I didn’t do a very good job of framing the photos, but I hope you can get the idea. The two pictures are right next to each other; stepping back and taking a single photo would have shown the scale of everything better.)

In the photo on the left Amy (who is only about 5 feet tall) is giving scale to a fallen tree. This would be called a “root ball” in a horticultural publication, but root “disc” or “plate” would be a better word. These large, flat root masses are a very common sight around here. This one is about 8 feet across, but they can be much larger; there is one at the north end of Lost Lake that must be about 20 feet tall.

a nurse rock

A “nurse” rock

Right behind where Amy is standing is a fine illustration of the reason for these “plates”. What you are seeing is a set of three decent sized trees (trunks are a foot or two in diameter)  with their roots spreading across on top of a large boulder. Only in the lower right hand corner can you see the roots making contact with anything that passes for soil.

Another phenomenon associated with these fallen trees is called a “nurse log” – as a fallen tree gradually decomposes you will see other plants and even whole trees growing directly on top of the log and drawing their nourishment directly from the log. This boulder is providing very little nourishment, I imagine, but I can’t resist calling it a “nurse rock”.

sunshineBy the time we got back to the trailhead the little bits of sky that we had seen poking through the clouds for most of the day had coalesced into a glorious wall-to-wall blue. This allowed me to get one picture of the group without the blur of a shaky camera.

Advertisements

February 5, 2013

Winter Potpourri

Filed under: Hiking, North Cascades, Snowpack, Weather — Tags: , , , , — geezerwriter @ 1:02 pm

I’ve been kind of lazy about posting lately, so I have a backlog of weather-related things to spout about.

The Great Inversion of 2013

A couple of weeks ago western Washington experienced a protracted temperature inversion. Usually the temperature of the air decreases as you go to higher altitudes (during the daytime, at least) due to the fact that the sun’s energy heats the ground faster than it heats the air, whereupon the warmer ground proceeds to heat the air from below. This situation is a bit like a pot of water on the stove: the lower layers are warmer, but warm things (generally) are lighter, so we get an instability where the warm stuff rises and the cooler falls, and everything gets all stirred up and burbly.

At night the opposite situation often occurs, since the ground also cools off faster than the air, giving the common situation where there is a layer of cooler air near the ground, often causing fog and frost or both. Sometimes you’ll even see frost forming on the ground when a thermometer a few feet higher reads several degrees above freezing

But the thing that breaks that cold layer down and makes our daily atmospheric pot roil and boil was that business about the sun heating the ground – which doesn’t happen so much here in the winter. We sometimes forget what the sun looks like for extended periods of time. Anyways, now and then conditions converge that allow that frosty layer to persist for days and grow to hundreds of feet thick. And that layer is quite stable, with the heavier, colder air at the bottom and warmer at the top. Usually we think of stability as a good thing but in the atmosphere it has the downside that the air just sits there, allowing all the dust and nitrogen oxides and other crud that we are so good at spewing to build up and form a low-lying smoggy cloud that further inhibits the sun from warming the ground, and so on, and so on.

[You read further, and more authoritative words about this and other meteorological phenomena on Cliff Mass’ weather blog.]

Another side effect of the inversion was that it gave us an extended period without new precipitation, allowing the snowpack in the mountains to settle and consolidate and bringing the avalanche danger down into a comfortable range. Just a day before the inversion was broken by the arrival of a strong Pacific storm Amy and Jan joined me as we left the gloom of the lowland smog for a snowshoe outing near the Mount Baker Ski Area. We were only a few miles from town and a few hundred feet in elevation when we passed out of the inversion layer and the sun broke through.

Snow or Frost?

Snow or Frost?

As we continued up Mount Baker Highway along the North Fork of the Nooksack River just before the road turns and climbs steeply to the Ski Area, we were admiring the heavy layer of snow on the trees along the road when it occurred to me that there hadn’t been any noticeable precipitation for about ten days. Snow on the trees is a pretty common thing up in the mountains, but we were seeing something that you usually see the morning after a heavy snow – these evergreens are shaped to shed the snow pretty quickly. Furthermore, the trees on the surrounding hillsides, and even the tops of some of the taller trees, were completely bare, so the snow was not fresh – how had it hung around for so long?

I puzzled about this most of the day and it wasn’t until we were on our way back to town that it made some sense. Maybe that snow wasn’t snow at all but a heavy layer of hoarfrost that had built up for days. Or maybe a combination of both. There is a phenomenon in the mountains called “cold air drainage” which results in localized inversions – the cold night air drains down the river valleys and picks up fresh moisture from the unfrozen river. While we were above the level of the coastal inversion, the calm stable weather meant that there were no windstorms to knock the snow off the branches. The sun had melted the tops of the trees but the snow had persisted or even grown with hoarfrost in the shade along the river.

Southern Sky

Southern Sky

I wish now I had spent more time trying to get some better pictures since this was such a combination of things that I might just never see it again.

We had a beautiful day for snowshoeing although the weather system that would ultimately break the inversion down was heading in from the west, making for some interesting skies. On the picture on the right you can see in the clouds a dark V-shaped pattern pointing toward the sun – just one of a number of odd fantastical shapes that we saw.

I will tack a picture gallery at the end of the post.

A Return to Normalcy

The "View" Point

The “View” Point above Cedar Lake

Loons on Cedar Lake?

Loons on Cedar Lake?

That snowshoe outing was on Tuesday, January 22, and by Thursday the inversion was pretty much gone and we had a nice sunny hike to Alger Alp. [As always, you can read about that hike on Jan’s blog, D-Jan-ity.] But another week later we were back to full-blown normal, a bunch of crazy geezers hiking in the chilly rain to Pine and Cedar Lakes. After visiting the lakes we hiked on over to Raptor Ridge, not so much for the view but because of the overhanging rock ledges that form shallow caves and provide some shelter from the wind and rain.

The State of the Snow

This morning I dug out my spreadsheets from last year that I had used to compare the snowpacks for the last several years and updated them with this the current Year-to-Date data in an attempt to get an idea of what this year’s hiking season might be like. The last two years have seen abnormally high snowfalls in the mountains which have delayed and disrupted our high country hiking. Here is the new graph:

Snow Depth (Water Equivalent) at 4900' near the town of Glacier

Snow Depth (Water Equivalent) at 4900′ near the town of Glacier

The blue line is this year so far and the red is an average for the last ten years or so, with the most extreme years (2006 was very low and 2011 & 12 were very high) omitted. [That “moderation” of the average seemed reasonable last year when I started doing this, but maybe there is a new “normal” developing?]

This year’s line is a little above “normal” but not enough to make a prediction – it seems to be the late season snows that have the most effect on the hiking season. Notice that in 2011, the year they couldn’t open the road to Artist Point, the snow depth was pretty average until well into March but then it snowed like crazy through most of May and it didn’t clear until mid August. Last year was a bit on the high side at this point before the ceiling fell in and it snowed through April.

Snowshoe Gallery

Swift Creek Valley from Artist Point area

Swift Creek Valley from Artist Point area

And one in the bush

And one in the bush

A bird in the hand

A bird in the hand

taking flight

Trudging uphill

Trudging uphill

Blog at WordPress.com.