Image courtesy of WeatherBell





My blog on UW College of the Environment Censoring of Social Media is Here.

It is snowing right now at Stampede Pass at 4000 ft in the central Washington Cascades. At Stevens Pass, at a similar altitude, there is snow and slush on the roadway (see below). An image that will warm the heart of any Northwest skier.The upper level pattern associated with the influx of cold and precipitation is a classic and may be familiar to a regular reader of this blog (see below). This 500 hPa pressure level map (about 18,000 ft above sea level) shows a big ridge of higher pressure/heights over the Pacific, with a sharp, well-defined trough moving southward into the Northwest.Memorize this pattern. It is the one that brings lowland snow after November 15th. Alas, temperatures are too warm for that this early in the season (something that brings a smile to all snow-challenged Seattle mayors).Satellite imagery show cold, unstable air approaching western Washington and Oregon. You see the popcorn like elements off the coast? Those are convective showers--intermittent rain for us near sea level, snow showers above roughly 4000 ft.With westerly (from the west) flow aloft, the western side of the mountains will get plenty of precipitation as the air is forced upwards. To illustrate, here is the forecast total through 5 PM tomorrow. 1-2 inches of precipitation could fall west of the Cascade crest and profound rain shadowing over the Columbia Basin of eastern Washington. Want dry conditions and some sun? It is available.But what many of you really want to know about is snow. The forecast total through 5 AM tomorrow (Wednesday) shows snow above roughly 3300 ft, with up to a half-foot in favored locations. The Rockies and its eastern slopes get hit hard again.And for snow/cold lovers I have more good news. The Blob offshore is weakening with sea surface temperatures off the Northwest coast returning to near normal.Want more good news? The latest European Center 46-day forecast is going for colder than normal temperatures through November 22 (see below, blue color is below-normal temperatures). Time to wax your skis.________________________