Temperatures around twenty degrees at all elevations and bluebird skies are over the Steamboat Springs area this Thursday at noon. Warming temperatures and sunny skies will last through Saturday before increasing clouds on Sunday foreshadow a pattern change that will bring a series of storms overhead through Christmas week.

A ridge of high pressure has built over the West ahead of a sprawling low pressure area extending southward from the Gulf of Alaska and westward to Siberia. A series of waves traveling along the low pressure’s southern boundary will tap areas of subtropical moisture as they travel eastward across the Pacific, first weakening the ridge of high pressure overhead before moving it toward eastern North America.

The first wave strong enough to weaken the ridge will cross the Pacific Northwest coast on Saturday before traveling across Montana on Sunday. So the beautiful weather with mostly sunny skies should continue through Saturday, with the high temperature reaching near forty degrees in town, over ten degrees above our average of 29 F, and thirty degrees at the top of the Steamboat Ski Resort.

The wave will bring cooler air for Sunday, with high temperatures dropping several degrees along with some breezes ahead of the next stronger wave currently promising increasing clouds during the day and light snow showers beginning as early as Sunday night. The light snow should continue through Monday, becoming heaviest Monday night, before the storm passes ahead of a quick-moving ridge of high pressure which should bring nice weather for Tuesday.

Right now, a stronger storm, perhaps the remnants of the northern Pacific low pressure area, is forecast for around Christmas Day, though there is weather forecast model uncertainty as to whether the storm splits and weakens, according to the European ECMWF, or remains stronger and more cohesive, according to the American GFS.

So enjoy the beautiful start to the weekend, and I’ll have more details about the impending pattern change for Christmas week in my next regularly scheduled weather narrative on Sunday afternoon.