Precipitation making appearance
After one of the driest early December periods on record, moisture has returned to the Inland Northwest. As of Tuesday morning, only .15 inches of rain and melted snow was reported at Spokane International Airport. But that total has gone up as a series of moist Pacific storm systems were forecast to move across the region on Wednesday and today.
The new snow that fell Monday night and early Tuesday brought Spokane’s total to around 9 inches for the season. The normal snowfall to date is approximately 20 inches. Last year, in 2010, we had a whopping 33.3 inches.
We still have a La Niña, the cooler than normal sea-surface temperature event, in the south-central Pacific Ocean. This particular event is weaker than the one last year, when much of the Inland Northwest reported above normal amounts of snow. Also, solar activity is much stronger this year compared with readings at this time last year. The combination of a weaker La Niña, increased solar storms and other climatological cycles have contributed to the dry spell in early to mid-December.
According to the Climate Prediction Center, the majority of computer forecast models are predicting that La Niña will weaken substantially in January and February, but its global effects will continue through winter.
Recent weather patterns have looked more like an El Niño, the warmer than normal sea-surface temperature event. During La Niña events, the Northwest often sees above normal snowfall about 70 percent of the time. This may be one of those oddball years. For example, as moisture is finally increasing, much of it is coming as rain rather than snow. Another warm spell with rain is expected toward the middle of next week as moisture streams in from the southwest. If it doesn’t get too warm, the higher mountains should see plenty of snow from these Pacific storm systems.
Winter officially began over a week ago and a lot can happen between now and March. Based on climatology, when our region has a dry December, January and February will often be wetter, and snowier, than normal. Despite the milder conditions into next week, we should see increased snowfall on the back side of the rainy weather pattern.
Contact meteorologist Randy Mann at randy@ longrangeweather.com.