Meteorologist talk a lot about the jet stream when talking about weather patterns, but what exactly is the jet stream? What does it do? Bree Guy tells us more about the phenomenon and how it’s going to factor into the warmer weather on the way.
They're like a river of air but about 30,000 feet, sometimes more or less, above Earth’s surface. Jet streams are narrow , strong, fast moving air currents that impact weather patterns and air travel, as this is the typical cruising altitude of a commercial aircraft. Hence the name: jet stream. Jet streams can strongly impact flights. For example, if traveling east, they can cause aircraft's to land hours before the normal landing time.
Jet stream winds on average are about 110 miles-per-hour but can reach above 250 miles-per-hour in some parts of it. These are called jet streaks.
There are 4 main jet streams, two polar and two subtropical.
In the Northern Hemisphere, jet streams typically move from west to east, like our weather. That is no coincidence. Jet streams help guide weather.
The cause of jet streams occur closer to the surface, when a warm air mass meets a cold air mass.
As the sun doesn’t heat the Earth’s surface evenly, especially during the winter, these temperature differences are largest during this time of year. This is why jet streams are typically stronger during this time of year.
Going back to basic meteorology: warm air rises and cooler air sinks. The warmer air near the equator rises a lot more than in the mid-latitudes, forming opposite circular motion as cooler air moves in to replace it.
At these positions where the cells are, the temperature difference is the largest, which in turn, increases the winds.
Because the earth is rotating, jet streams flow from west to east and not north to south. This rotation applies a force on the air that causes momentum as the air moves away from the equator.
As the air rises, there is less friction, which causes it to move faster and faster eastward higher up in the atmosphere.
So how does the jet stream impact weather?
Jet streams follow the sun and can change shape, move between latitudes, and even sometimes seemingly disappear.
Typically north of the jet stream is cooler and south of it is warmer. Again, following the sun, in the summer it extends northward, allowing warmer air to flow into the mid-latitudes. In the winter, typically we see it dip south, allowing cooler air to spill in from the north.
The lift northward is what we will see later on this week, with warmer temperatures. However, jet streams react with other atmospheric variables, such as locations of lows and highs. This is another factor impacting the weather pattern later this week.
That’s your new Bree Guy Tells You Why!
ncG1vNJzZmivmpawtcKNnKamZ56axLR7y6iamqRfl7%2BmsYygrLJlpJq5rb%2BMsqauZaedxm62xK2qraqVlrq0ecCnm2agn6x6tbTEsmSipaCWsLV506GcZq%2BRp7puwc9mmqilmaO0