g Troughs

g Jetstream

Our weather is turning active indeed as we plow into the late fall and early winter months. Globally, we presently have seven distinct long waves circumventing the northern hemisphere, inferring an active weather pattern. The dashed yellow lines represent the troughs and the green wavy arrow circling the globe is the *mean jetstream flow. (*meaning the "avg." flow, though sometimes the jetstream can pack a punch; in that case the jetstream would be the mean mean jetstream!)

It's looking like we've got three troughs to contend with over the course of the next week. In the picture, they are just off to the west, off the west coast and lastly south of Alaska. The first will bring the most significant cool down we've seen so far this year. A short wave diving into the first trough looks to merge with the second and possibly bring in some wintry precipitation over the course of this weekend. The scenario would be a cold air mass in place with warm and humid air pushing in from the south with a southern tracking Low, overrunning the cold. These type of set-ups are famous for snow to sleet to freezing rain to ultimately rain events as cold air gets eroded. The last trough looks to move in next Tue./ Wed... We'll get through the first two before talking about next week

Fine-tuning still needs to be done with the weekend forecast, though confidence is high that we will get cold so, remember to dress in layers and wear a hat. About 30% of body heat escapes from an uncovered head.