ASK THE METEOROLOGIST
Which is the greater influence on the positioning of weather systems — the jetstream or weather systems?
Chris Stoney, Rogue River
The jetstream is the main weather phenomena that dictates where our weather systems will move. There are two major patterns within the jetstream — high pressure ridges and low pressure troughs. Typically, areas of high pressure are rises in the jetstream …where dry weather and mostly clear conditions are common.
Low pressure troughs on the other hand, are dips in our jetstream. With areas of low pressure we tend to see wet weather — whether it be rain, sleet, freezing rain or snow. In some cases, areas of low pressure can break off from the jetstream. This is known as a cut-off low, and can be very difficult to forecast. Once they have broken off, because they are no longer within the general pattern of the jetstream, their future movement can be challenging to predict.
Overall, the jetstream is what influences where our dominant areas of high and low pressure, or weathermakers, will move.
Meteorologist Alyssa Caroprese