Even though an average winter gets 6 inches of snow, Portland has only a 1-2% chance of having a White Christmas. Specific to this year, Phil Volker of ERF Long Range Weather Forecasting says, “Given what is showing up from the models, I do not see any low elevation snows west of the mountains through New Year's! All of you should be able to relax with families during Christmas and New Year's and not worry too much about road or transportation issues…”
That being said, our current La Nina weather increases our likelihood of low-elevation snow as we go into January. La Nina has been developing all fall and predictions of a colder, wetter winter were predicted at the beginning of October. We have since had a rather mild late fall and early winter. However, similar La Nina years in the past were mild in December and snowy in January. We will see and are prepared if and when snow occurs.