“Winter is icumin in…”

No, I won’t finish Ezra Pound’s poem, beyond noting that at least we don’t have rain or slush. We do, however, have darkness. And cold. It is warming up, though. We might be up to 20 below  by this afternoon.

Noon from my south window. Unfortunately the camera insisted on focusing on the screen.

The sun will rise this morning at 10:09 am and set at 3:08 this afternoon, for 4 hours 58 minutes of daylight. We’re now losing 5 minutes and 39 seconds a day, and the sun at noon is only 4° above the horizon. I can barely see it out of the south window at noon, and I can probably say goodbye to it until well into January. There were enough ice crystals in the air in town Saturday to produce sundogs, but I think that was just in town. It’s cold enough that cars are putting quite a few ice crystals in the air.

The snow is still settling a little, but we haven’t had much snow accumulation for the last two weeks – just an occasional trace or at most a tenth of an inch a day. While there’s not much chance of snow, the Weather Service is forecasting a Chinook wind for midweek, with temperatures on the hilltops possibly close to freezing.

Why is a Chinook so warm? Moist air climbing a mountain range – in this case the south side of the Alaska Range – cools, and moisture condenses and falls out as snow. In the process, the latent heat released as the water condenses is transferred to the air. When the air moves down again on the lee side of the range, it warms, and the heat added by the condensing water makes it even warmer than it was on the windward side of the mountain. Here, away from the passes, it tends to ride over the colder air near the ground, so it’s not likely to get above freezing where I live. I certainly hope it doesn’t, because above freezing temperatures this time of year just makes things slippery.

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