Weather Eye: Arrival of December will bring change in weather pattern

Today will be the sixth day in a row without measurable rainfall as we have enjoyed beautiful sunny days and crisp cold nights. Beginning on Thanksgiving Vancouver had a low of 32 degrees, Black Friday was chilly with 27 degrees and 24 degrees Saturday and 25 degrees Sunday. Cold enough? Monday morning was the winner so far with 23 degrees.

That is plenty cold and winter is still a couple days away for us weather and climate folks. We begin climate-wise on Dec. 1 while the astronomical beginning is of course Dec. 21 at 7:27 local time.

As we approach the month of December, the weather pattern will once again begin to change. Remember November started off on the wet side? December appears to be a repeat performance. The storm track will consolidate and carry along Pacific frontal systems to the Pacific Northwest. That means we finally get some snow in the mountains.

The air mass when clouds and moisture arrive on Thursday will be chilly and light snow could fall to our foothills briefly. Precipitation amounts will be scant but heavier with another weather system on Friday.

A much more robust storm arrives for the weekend, but a southwest flow of air will raise snow levels to the timberline or higher before cooler air follows. Bottom line is that we will be entering an active weather pattern in December. Hopefully it won’t follow November with the last half of the month only providing light precipitation. I expect November to end up with below-average rainfall.

You’ll recall November’s average mean temperature recently was 4.5 degrees above normal, but with these chilly nights as of Monday they were only about 1 degree above normal.

I made my annual Thanksgiving trip to Sunriver, Ore., last week and both driving there and returning home there was no snow at all at Government Camp. Close-up views of the mountain Sunday showed more rockier areas than snowfields above the timberline. Unusual not to have snow on the roadways or at least roadside snow this time of the year. I can only recall a few years without snow in the 28 years of that tradition.

Enjoy the sunshine before the rain returns.