Weatherwatch

The heart of winter

By Bill Biddle
Your weather aficionado takes cues from poets Neil Young and Donald Hall to start and end this month’s “Weatherwatch.” This column reveres the change in our seasons – imagine writing “Weatherwatch” from and for Miami, Florida, where the average temperatures may vary by 30 degrees in a year. Barring hurricanes, there’s not a lot going on.

I want to live,
I want to give
I’ve been a miner
for a heart of gold.
It’s these expressions
I never give
That keep me searching
for a heart of gold.
– Neil Young

You don’t need to search anymore because the heart of winter – which is gold for our valley – has arrived. We are deep into it now.

Early in the month you may get the feeling that winter is nigh over, because of the increased daylight and less contact with marine air. That will be a false assumption, because later on February will again feel more like winter. Below-zero cold, more snow, more daylight will all mark the month, and you can even look forward to night skiing a cloudless full moon on Feb. 7. “As the days lengthen, the cold strengthens” – this ancient proverb at first read seems completely wrong. While it’s obviously true that the longer something is exposed to something warm the warmer it will get, there are other factors at work.

One of the most important is that there is more snow on the ground in February than in December, which holds the shortest day of the year. Snow is a tremendous insulator and reflective surface which counters the promise of warming a longer day may hold. Snow traps in temperature and holds onto it stubbornly. February still means very cold nights, and that cold penetrates even more deeply than the suns rays.

This is another reason that February is the heart of winter – daytime air temps may start to feel downright mild but nighttimes will remain quite cold. The average temp may go up but the bottom of the spread doesn’t move nearly as much, if at all.

There are over two feet of snow in the valley now and more to come in February, making this possibly one of the snowiest years in the valley of the past 50. We’ll have nearly 100 inches total snowfall by the end of the season! (That’s total, not accumulated. You will still be able to see out your first floor windows.)

While our beloved and tempestuous La Niña will have lost her effect by the end of the month and with her departure we may find a warmer spring, that doesn’t mean we aren’t still in the heart of winter.
Here’s a hint on forecasting February snowstorms: Be attentive to the sky and look for vapor trails from planes. In an otherwise clear blue sky with visible vapor trails, you can forecast that there will be snowfall within 48 hours. What you are seeing in those vapor trails is moisture that is evenly distributed across the sky – not enough in any one place to form a cloud, but enough to condense into vapor due to the passing of a cold plane fuselage.

Back to February – the heaviest 24-hour snowfall for the whole winter will come sometime the middle of the month. You’ve been warned. January was definitely the coldest month and February probably won’t have as many mornings of sub-zero temperatures. A walk under the full moon in 10 below zero will give you the magic of a Methow Valley winter more than any email or exclamations over the telephone. If ever you wanted to express something romantic, Feb. 7 really ought to be a time to consider. (We know who I’m talking to – ski or go home!)
My friend Donald Hall ended his recent column in the New Yorker with the following line, and I can’t think of a more apt way to make the end of mine. Until snow falls again!

“Out the window, I watch a white landscape that turns pale green, dark green, yellow and red, brown under bare branches, until snow falls again.”

Feb. 1, 2012

Links:

National Weather Service

Northwest Weather and Avalanche Center