Why is weather affected by the jet stream?

That question is sort of backwards.

The jet stream is a result of temperature gradients. This means that the jet stream will typically bend around the south side of cold air masses and around the north side of warm air masses (in the northern hemisphere at least.)

But, the jet stream circles the entire world, not just the areas where there are cold and warm fronts. On the global scale, the jet stream is caused by the temperature gradient between the equator and the pole. This gradient, along with the Coriolis effect is what gives the jet stream its direction (from west to east.)

As the jet moves along, it pushes air masses along with it in the form of cold fronts.

Eh, I sort of rambled. Hopefully you can find an answer in that.

the severe warmth that Alaska has been experiencing those days is linked with an exceedingly stable top point severe. whilst i've got no longer seen any information from the point of the jet circulate (2 hundred-3 hundred mb), a minimum of on the mb point (~18000 ft) that is been a notably unusual difficulty. The statistical version of the geopotential top (that's comparable to stress) and temperature have reached 5 nicely-known deviations faraway from the advise. that is out previous black swan territory.

because of the high pressure systems they blow air down to the surface of the earth from the streams and then low pressure systems suck the air back up like a giant vacume but nothing realy sucks it is just that there is a difference in pressure it sucks it because theres less pressure up there and more down here because it was just forced down there so now it's being forced back up.

get it?

Download Weather Toolbar - Instant weather reports, forecasts, and radar images anytime for free - http://surl.in/HLWTD261252BMRMTGQ

tricky point. research on google. that will could actually help!