Area’s terrain helps create varying climates

We’re closing in on the middle of January as another series of Pacific storms continues to bring more snow to our region.

As of this early week writing, the Spokane International Airport was nearing 30 inches of snow for the season. The total snowfall for the 2006-07 season in Spokane was slightly over 35 inches. The average is 45.5 inches. In Coeur d’Alene, just 30 miles to the east, nearly 60 inches of snow has fallen with a yearly normal of 66.7 inches.

The Inland Northwest offers a variety of landscapes including lakes, valleys and mountains. These features result in many different “microclimates” within very short distances. Across much of the central United States, by contrast, weather conditions are not widely affected over larger distances due to the lack of mountains and lakes. Therefore, temperature, rain and snowfall forecasts would be the same over a given area. Here in the Inland Northwest, much more snow will fall in the Idaho Panhandle’s higher elevations than across the lower elevations in eastern Washington, including Spokane and the Spokane Valley.

There are occasions when storms will literally sit over a particular area. This happened in late December as a system dumped over nine inches of snow in Coeur d’Alene. By contrast, Spokane, the Spokane Valley and other areas reported generally less than three inches.

Many folks called the snow in Coeur d’Alene a “surprise.” Well, snow was expected for that particular time frame, and forecast amounts were close for most areas. In this case, Coeur d’Alene picked up over three times the amount of other cities and towns a short distance away. This type of pattern, when a localized area receives much more than other areas, doesn’t happen often, but there have been a number of instances when this event occurs. To forecast those anomalies is difficult if not impossible. (I still heard about this, anyway).

As 2007 came to a close, Coeur d’Alene received 26.56 inches of total precipitation, coming in just above the average of 26.11 inches, despite a dry summer season.

In Spokane, precipitation for the year was only 13.97 inches, below the average of 16.67 inches. At the Spokane airport, where official observations are taken, 20.1 inches of snow was measured for December, with a monthly total precipitation of 3.72 inches. The largest one-day snow total was only 1.9 inches.

In the Spokane Valley, where Felts Field airport sits approximately 400 feet lower in elevation than Spokane International, total snowfall was a bit lower, although no official records are kept for that location.

As far as our near-term weather is concerned, our snowy weather pattern will continue through February. The coldest time of this winter season should be toward the end of this month as temperatures drop to near the zero mark, even in the lower elevations.

Milder temperatures are likely around the first week of February and again in the first week of March. That is a assuming our La Niña, cooler than normal sea-surface temperature event in the south-central Pacific Ocean, continues to maintain its intensity. A “big mountain thaw” during that first week of March may substantially reduce snowpacks in the higher mountains, but not enough to shut down spring skiing. However, there could be some minor lowland flooding at that time.

With more snow in the forecast, seasonal totals for the higher mountains should be above 300 inches with some isolated areas approaching an amazing 400 inches. At the International Airport, I still see 45 to 50 inches of total snowfall with about 85 inches in Coeur d’Alene. Still looks like a great year for snow. Next year may be a different story. Stay tuned.