Weather Eye Stay tuned to local forecasts as opposing air masses approach

first_imgPatrick Timm is a local weather specialist. His column appears Tuesdays, Thursdays and Sundays. Reach him at http://patricktimm.com. Once again we come to a crossroads in the weather business. We have an active warm southern jet stream and a cold northern jet stream that are evidently at odds over just where they want to settle in. Latest computer forecast models are in the same state of mind. Cold versus warm.Maybe fortunately for us and those who do not like cold and snow, the odds usually go to the warmer southern jet stream. We need no more snow to disrupt our lives. Once again, it may be a late-night call whether we see another bout of winter weather.Another cold air mass is gathering in British Columbia and is heading southward. The southern jet stream is just offshore and desires to head north. This battle zone is what we call a confluent boundary. The warm and cold air join forces, and there can be a thin line between the air masses. Even 50 or 100 miles can make the difference between rain and snow.There is the possibility cold air sags down into Northern Washington via the Fraser River outflow. More cold air could settle in the upper Columbia Basin near Omak and, with a large area of low pressure off our coast, draw down some of that cold air via east winds and the Gorge. Sound familiar?I think if this should occur around mid-week, it would be short-lived and the warmer wetter jet steam would push back the offending cold air. Not all the models are in agreement that cold air reaches us, but as long as it is up in the air, we need to keep a keen weather eye to our north.last_img read more