More snow so far this year than all of last year

We have entered the second half of the 2007-08 winter season. Snowfall totals across the region are currently averaging well above normal levels.

At the Spokane International Airport, exactly 35.8 inches of snow has been measured through Jan. 15. The normal to this date is approximately 27 inches. The normal snowfall for the season at the airport is 45.5 inches. We’re already ahead of the entire 2006-07 season, as only 35.2 inches of snow was measured because most of the moisture fell as rain in the lower elevations.

If Coeur d’Alene does not receive another snowflake between now and spring, it would see a final snow total above its seasonal normal. The average snowfall for Coeur d’Alene is 66.7 inches. As of early this week, more than 75 inches of snow has been measured, more than double Spokane’s amount. There were many occasions when the snows missed the towns in Eastern Washington, but were concentrated over North Idaho.

Skiers and snowboarders have seen some of the best conditions in the mountains in years. Higher elevation snowfall totals to date are ranging from 150 to 250 inches. Some isolated areas in North Idaho have reported snowfall totals near 400 inches. When the season is over, most high mountain locations should observe at least 300 inches of snow.

One reason we’re seeing plenty of moisture and cold weather is the cooler than normal La Niña sea-surface temperature event in the south-central Pacific Ocean. Readings near the equatorial regions continue to be well below normal levels. Over the last month, ocean temperatures have cooled even further, which means that La Niña has been strengthening.

This sea-surface temperature phenomenon has been influencing global weather patterns over the past several months. Here in the Inland Northwest, we typically see colder and snowier winter seasons during a La Niña. So far, this has been the case. Last year, we had the opposite sea-surface temperature phenomenon, El Niño. The warmer waters near the equator will often point to milder winters in our region. For the winter of 2006-07, the lower elevations had the rain while the air was cold enough to produce plenty of snow in the higher mountains.

Assuming that La Niña continues to maintain its intensity into the spring, we should see more snow. However, I don’t believe the second half of winter will be as snowy as the first half. The Spokane International Airport should receive a snowfall total of approximately 50 inches by season’s end. In Coeur d’Alene, I wouldn’t be surprised to see a snowfall total of 100 inches by the middle of March.

The coldest weather of this winter season should be toward the end of this month. Temperatures should fall into the single digits or lower in the valleys with below-zero readings expected in the higher mountains. Then, as the colder air moves to the east, milder weather will invade the region in the first week of February sending highs well into the 40s. We may see an isolated 50-degree reading. Another round of mild weather is expected in early March that will ultimately reduce snowpacks in the mountain areas leading to some lowland flooding.

The early March thaw may seem like an early spring, but the mid-March through mid-June period should be cooler and a bit wetter than normal across the Inland Northwest as La Niña continues to influence our weather patterns. We should also see above-normal thunderstorm activity during the upcoming spring season as well.