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Whether it's through the eyes of a meteorologist or through our own eyes it is best when watching for weather to look to the west. West is upstream in the flowing river of air - most of the time. Sometimes this atmospheric river comes to halt or worse yet changes course. In both cases storms can then sneak up on us, from behind. Hi, I'm Dave Thurlow for The Weather Notebook.

The jet stream is the central and fastest current in the river of air above us. As it moves, so do the storms. During the summer, the jet stream moves north into Canada, and in the U.S. is often under very weak upper level winds--less than 10 miles an hour. If a thunderstorm pops up, there's not enough upper level wind to push it along down stream. The result is a thunderstorm that sits in place. If it's growing it may spread out in all directions and appear to those to it's west, that it's heading in their direction.

In the other case, when the jet stream changes course, the results can be devastating especially along the east coast where when storms head out to sea, they seem to be gone and forgotten. When a wiggle in the jet stream separates from the main flow, it often closes off into circle. If a weather system gets caught in this circular current it may move on, only to appear again but this time from behind our backs. The Perfect Storm, the subject of this summer's blockbuster movie, did this, as did last year's Hurricane Dennis.

Thanks to today's contributing writer Bob Henson and thanks to Subaru the beauty of all wheel drive.