Fog and cold ruled last month
The winter season thus far has been tough for those of us who want sunshine and milder temperatures. I’ve heard of numerous instances of people falling on the ice outside their homes and parking lots. Even yours truly, my wife and business partner took nasty dips on the ice. Doctors are saying that they are seeing countless number of folks in the emergency room with broken bones due to falls on slippery surfaces.
Fog and freezing fog at this time of year is not that uncommon. However, since the beginning of the recent outbreak of much colder air invading our region, many of us have been ready to head south because of all the cloudy and gloomy days. From Dec. 1 through Feb. 5, we’ve endured 47 out of 67 days with total cloud cover. There were only two days when skies were clear along with 18 days when it was partly cloudy at the Spokane International Airport.
In Coeur d’Alene, climatologist Cliff Harris reported only 26 hours of sunshine for the month of January.
Fog is merely a cloud that is grounded. High barometric pressures usually mean light winds and sinking air. Low-level moisture gets trapped, along with pollutants, near the surface of the earth much like a pot lid traps moisture in potatoes cooking on the kitchen stove.
When the air temperature reaches its “dew point” (the actual temperature of the air when it’s saturated with moisture), this moisture usually condenses as dew, frozen dew called frost or fog. Most of the time, high barometric pressures gives us clear, cold nights during the winter months with little wind. If there is a good source of moisture, such as Lake Coeur d’Alene, or from recent storms, we’ll see that fog form and persist, especially in the lower elevations.
Often, except perhaps during this type of winter season where there’s plenty of moisture on the ground, this layer of fog will burn off when the sun warms the ground above its dew point sometime the next morning. Much of this moisture at ground level usually evaporates, but low stratus clouds may linger much of the day, especially from late November into mid-February when the sun angle is low on the horizon. Then, later in the evening, the whole process begins again, and we see more dreaded fog as the ground cools below its dew point.
In addition to the fog and snow, it was extremely cold in January. Last December, the airport reported an average temperature of 28.6 degrees which is 1.4 degrees above normal. But January was very different. The mean (average) temperature was only 24.7 degrees, which was 2.6 degrees below normal. Coeur d’Alene was 3 degrees below average last month and 10 degrees colder than January of 2006, which was the warmest January on record dating back to 1895. For the first five days in February, the airport was more than 3 degrees below average while Coeur d’Alene was 4 degrees below normal.
But hang in there – better weather is in sight. I still see drier and milder conditions arriving around mid-February following this chilly, icy and foggy start to the year’s shortest month.
Look for a series of quick-moving storm systems passing through the Inland Northwest in late February and early March. There will be light snows at times, but they will quickly melt in the driveway before one has time to shovel them off. It’s also possible that one or more of these storms may produce some strong winds. Much warmer temperatures are likely in mid-March.
April should be cool at first with warmer days likely by the end of the month. Precipitation should be less than usual for the 30-day period due to a stubborn ridge of high pressure that may not break until after the first day of spring, April 20.
Next week, I’ll address the report that was issued last week about global warming and how most scientists believe that human activity is the primary cause. There is plenty of evidence to support many sides of this issue.