Snow Festoons

Snow does funny things sometimes.

I’m not talking about the wet snow you can build snowmen from, or the cold snow on warm ground that produces depth hoar. I’m talking about plain, dry, snow that has built up over a period of weeks or months on surfaces exposed to the air, like a picnic table or a fence rail. Fresh-fallen, it’s like powder – but it doesn’t stay that way.

Every snowflake has parts that stick out, and other parts that are concave. While the snowflake is falling through supersaturated air, the points that stick out attract the most moisture, and grow fastest. Not so once it has settled to the ground. Then the points tend to evaporate, and the moisture collects in the concave areas. Where two flakes touch, an ice bridge will form between them. But undisturbed snow is still mostly air, with a three-dimensional, lacy structure.

This year's festoon. You can see the hanging part through the lattice, but the base is still attached to the top rail. (Yes. the window needs cleaning, but from the outside.)

Sometimes that lacy structure is even flexible. I have a lattice with 2x4s on top. We don’t have much wind, and every winter the snow slowly builds up on the 2x4s. 4” wide and 18” high is not unusual by early spring. As the air warms and the sun comes back, it begins to sag a little, and once it starts to sag sideways gravity takes over. The lacy structure continues to hold together, and if the snow is held to the top rail only by its weight, part of it may even slip off the top rail, while remaining held up by the rest.

This morning, Feb 18 2012

I don’t think it will hang as far this winter. It’s started to bend over, but we had a thaw at the very beginning of the winter, and the base of the snow is glued to the top rail by ice. Late yesterday a tear developed between the base, which is still stuck to the top rail, and the top, which now hangs at the bottom of the festoon. I took a photo this morning. Anyone want to make a guess on how long it will hold together until the whole thing tears awat?

North Pole Weather 2/13/12

The sun will rise this morning at 8:57, and set at 5:14 for 8 hr 16 min with the sun above the horizon — 6 min 49 seconds more than yesterday. The daily increase is almost constant now, as is the gain in noon altitude — .3° a day. The sun will be almost 12°, 24 times the solar diameter, above the horizon today.

It’s warmed up almost too fast, and there’s been a little dripping water. We don’t need that this time of year! Water just freezes into ice, and a thaw produces roads like glass. Warm weather is fine once it’s late enough in the season it will stay warm, but right now it’s more of a nuisance. Not that I mind the +20’s forecast for next week; I just don’t want it getting any warmer until March.

It’s staying light long enough I can attend afternoon seminars and drive home in daylight. That means I don’t have as much time for writing, and I’ll have even less when OLLI (adult learning) classes start at the end of the month. But right now I’m just enjoying the freedom to get out of the house without counting every precious minute of daylight.

Indoors, the Christmas cactus is blooming, and most of the citrus plants have put out new leaves. Haven’t started anything for the garden yet, but it’s time I begin getting my orders in to those luscious seed catalogs. Rocdor and Gina beans from Park’s definitely — this year the raised beds will be ready and I think I’ll go back to starting the beans indoors.

Fairbanks Weather 12/5/11

The sun will rise today at 10:30 in the morning and set at 2:52 this afternoon for a mere 4 hours 22 minutes of theoretical sunlight. Very theoretical, as the sun at its highest is only 3° above the horizon and clouds are hiding it anyway. The day-to-day difference in length of day is dropping, at least – it’s only a little over 2 weeks to the solstice.

We had a group reading Saturday, starting at 2 in the afternoon. I had to leave just before 3 and it was barely light enough for me to drive by the time I got home.

We actually had temperatures above freezing yesterday, which is a real pain this time of year. According to this morning’s radio, we got up to 47°F. The snowpack was settling, and it was about 7” deep when it got too dark to see yesterday evening. But I expect once it’s light this morning, fresh snow will have made up for the fact that snow was melting as it fell yesterday. (Well, that’s what I expected yesterday. As of 8:10 this morning, it looks like Fairbanks got less than an inch overnight, and we might get another inch at the most.) Good thing I don’t have to go anywhere today; the combination of above-freezing air temperatures, precipitation and below-freezing roads produces wicked driving conditions. In fact the schools and state offices are closed today because of the road conditions, the university says “use your own judgement” though it’s open, and employees at the Army base are allowed to be as much as two hours late. Blowing snow is expected on high ground, but not so much in the valleys. And it’s supposed to cool throughout the day, from current temperatures around 20°F.

Out my front door, about noon.

Next week it’s supposed to cool off again, going back and forth around 0°F, but with continued clouds and chances of snow. I’m glad for the plants this time of year, even if I do need artificial light for them.

P.S. at 10:20, still 10 minutes to sunrise. The snow stake shows a bare 8″, and it is not snowing. In fact the sky has only scattered thin clouds, and the temperature has dropped to 18°F.

Noon: It’s snowing, though small flakes and they’re falling straight down.  Any wind is confined to the hilltops.

North Pole Weather

I photoshopped this to brighten it a little. It's a gray day and the original was very dim.

March 28: Sunrise 7:22 am, sunset 8:31 pm for 13 hours 9 minutes of daylight. We’re still gaining 6 3/4 minutes a day. Yesterday that pesky ice from the November rain was just about gone from the pavement. except north of hills. Melting snow was still refreezing – overnight low temperatures were below zero until a couple of days ago, and are still forecast to be well below freezing.

Things may be slick again today, though – it snowed last night. Two to four inches for Fairbanks, officially. The snow stake shows 22” so I got enough snow to make up for last week’s melting and settling plus 2”. The wind spinner is up and spinning a little, with only a little snow sticking to it. The roads? I’ll have to see when I drive to OLLI (Osher Lifelong Learning Institute) classes this morning for the last session of “The science of smell.”

P.S. The roads were blown clear where the speed limit was above 50, and packed snow on slower roads. Lots of water coming back home, though, and it’s likely to be icy tomorrow. And we finished the science of smell with a discussion of champagne and terroir. Wonder if I can work some of that into Derry’s appreciation of fine wine?

More on Ice Melting

I meant to post on the leopard gene in horses today, but I just didn’t get the post finished. I took a few more pictures of melting ice yesterday, so I thought I’d put them up for today.

Note the difference between the left side of this block, which has been exposed to strong sunlight, and the side facing the camera. This particular block is either in the same orientation it had in the pond or upside down, as shown by the vertical fabric of the sunburned ice.

This coumn was a little better sheltered, but there is still some solar melting on the right side. Notice the clarity of the shaded ice.

The middle part, between the clear ice on the left and the wood on the right, shows the intergrain boundaries as seen from the end. This block must have been turned on its side relative to its original orientation.

The blocks for the single-block competition are 8′ by 5′ by 3′ and weigh a staggering 7,800 lb each. Needless to say, they are positioned by power equipment! The multi-block competition can have up to 4 carvers and use up to 10 blocks of ice, but the blocks are smaller–a mere 3′ x 4′ by 6′. Repositioning and stacking these blocks is done by cranes, and the crane operators really have a job hoisting these delicate carvings into precise position. Aside from Harvest Moment, the photos in yesterday’s post were all single block.