Why the jet stream usually shown as extending throughout all of North America on weather maps, even though most of the time no fronts are depicted in the area?
In weather forecasting, the jet stream is one of the principalle features we use to describe the overall weather pattern. When we talk about the jet stream, we are generally describing the zone of fastest- moving winds in the upper part of the troposphere (the layer of the atmosphere where weather occurs) which define the path storm systems travel and reflect the general division between warm and cold air. The height of the jet stream varies depending on the season and weather pattern, with an altitude of 10 km being a rough guideline for the altitude of the jet stream over Canada. While the jet stream is typically drawn as one curvy line on a weather map, there can actually be multiple segments of strong upper level winds and even significant breaks where upper level winds are weak. For presentation purposes, the jet stream drawn on weather maps is a simplified version of the often complex structure of the upper level wind fields. Meteorologists also talk about low-level jets where ar
