With the ridge of high pressure still spread over the west, temperature records in some of the lower elevations like Grand Junction could be broken today and tomorrow (low to mid-60’s), records set early in the last century. The high pressure ridge will begin to move east today and by Monday evening the upper level air flow will transition from NW to SW accompanied by high cloudiness & gusting winds. The low pressure disturbance will arrive by Monday evening.
Models seem to be in agreement of a fast moving closed low building over the 4-corners but lacking good moisture. Orographic lift over the San Juan’s should be enough dynamic to squeeze a few inches (2-5″) from this fast moving system above 11,000′ favoring southwest aspects. By Tuesday afternoon most of the actions will be over.
Late Wednesday there’s another system moving into the area into Thursday morning. Models are not in agreement on this storm so it’s a wild card.. Late Thursday high pressure builds back through the end of November but looking out into the Pacific there is a big storm system developing in the Gulf of Alaska and could bring decent moisture to our mountains as it slides down the west coast and moves onshore by next weekend. OpenSnow below seems excited about it … Stay tuned.
Between about December 3-6 expect the potential for snowflakes each day, with the deepest amounts in the southern mountains.
The map below shows the average precipitation forecast from multiple models through December 5th. To estimate snowfall for the December 3-6 storm, multiply the numbers by about 13 and subtract a few inches for the potential storms on November 27-28 and 29-30.
The southern mountains are favored (Wolf Creek, Purgatory, Silverton, less for Telluride due to the southwest winds). Snow amounts in the south could be 13-26 inches.
The graphic below shows 51 versions of the precipitation forecast for the European model for Wolf Creek. The green bars at the bottom are the average of the 51 versions, and they top out at about 1.8 inches of precipitation or multiplied by an estimated snow-to-liquid ratio of 13-to-1, about 23 inches of snow.