FEBRUARY 24, 1997
|Partly Sunny/AM Frost & Fog||Little Rain||Mostly Cloudy/Showers||Mostly Cloudy/Showers||Showers/Cool||Showers/Cool|
Forecast: High pressure controls the weather early in the week for some sunshine. Be aware of the possible frost and fog on the morning commute Tuesday and Wednesday mornings. Drive especially cautious over rural bridges where black ices forms more easily. By late Wednesday and Thursday, the high pressure fades and a cool, broad area of low pressure starts to dominate the Northwest. That will mean chilly showers at times Thursday through Sunday. The snow level may dip fairly low: 1000-2000 ft. Watch for a dusting down low on the higher hills later this week.
Washington Passes: Low snow levels later in the week and through the weekend. Could be tough for mountain driving Thursday through the weekend (snow levels 1000-3000 ft). Be prepared. This will mean excellent ski conditions with lots of new and quality snow falling. Updated pass information: 368-4499.
Weather Question of the Week: Why does ice often form on bridges?
Answer: It's likely more people are killed or injured in accidents caused by ice in Washington than any other weather-related phenomenon. Bridges and overpasses are especially vulnerable because they are elevated and not insulated with some of the natural warmth from the earth. On clear, chilly nights with temperatures below about 38 degrees, you can start to see ice form. Low-lying bridges are normally in valleys and the coldest air also drains to that lowest area, making it slightly more refrigerated and dangerous than the surrounding areas, adding to the driving surprise and danger. Moisture from fog or a nearby stream provides the source of frost or ice. Also be cautious--the frosty spots can remain all day in the shady spots. The SR-520 and I-405 exchange can have icy spots early in the morning before too much traffic gets on it.