How jet streams affect our weather: an in-depth guide

Jet streams are fast-flowing currents of air that meander around the world at around 8 to 15 kilometres above sea level. We know that these high-altitude winds affect the weather at the surface, but how?
In this in-depth guide, we explain how faster winds within the jet impact the shape of the larger jet stream and what this means for the weather at the surface. We also take a detailed look at how faster parts of the jet stream cause vertical air motions which affect surface weather. As this is an in-depth video, links to supporting videos that cover some of the concepts discussed will appear at appropriate times.
Written and presented by Jodie Ramsdale Animation by Mark Machin Music is YellowDayz ©, composed by Amelie Machin
Note: this was previously uploaded on 1st March 2021. It's now been uploaded again along with some links to supporting videos.
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[@karlfrankeser]

Love the content, using it for my PPL(A) studies! Keep it up!

[@FlyTheSkiesTV]

What a fantastic video! Thanks for uploading it! Great job Met Office!

[@user-mj7hs1qj2b]

very useful and interesting, thanks for making it so clear!

[@johnwelbourn3811]

What a brilliant video! A real Eureka moment for me in my lay understanding of meteorology.

[@NativeVsColonial]

Very good graphics and clear narration 👌

[@solomon4554]

Very well-explained

[@u.jayaprakashraju3218]

wonderful vedio...i clearly learned some introductory concepts

[@geostudent]

Wow nicely explained

[@smbchannel8112]

Very helpful graphics in explaining certain weather events teaching Meteorology 101.

[@nyenoidz]

One detail of this video binds me up (starting at 2:20). The video describes high pressure to be the warm air in the south, and the low pressure to be cold air to the north. This information is contradictory to that which I learned before: warmer air is less dense than cold air, therefore having lower pressure compared to cold air. This did not impact my learning of jet-streams too much, but it has come to my attention.

[@captainshipman7377]

Typically there is not a direct correlation between temperature and pressure in the open atmosphere. To understand this you need to understand pressure levels. A pressure level is just the idealized pressure for a given altitude, for example at sea level it is 29.92 in/Hg where at 5,000 ft the pressure drops to 29.42 in. However, because warm air is less dense and expands, pressure levels are raised. This is why the tropopause is higher at the equator than at the poles. For a given altitude, the pressure in warm air will be higher than colder air, where pressure levels are squeezed together closer to the surface since it is more dense. In layman’s terms, in colder air the pressure decreases more quickly with height than in warmer air, even though at the surface the pressure might be the same

[@nyenoidz]

@@captainshipman7377 Wow, thank you for this. Over the past week I have thought again and again about why I was so confused the first times I watched this video. I had started to assume that, as you said, a column of warm air would have more pressure at the tropopause than a column of cold air at the same level. You've blown away any former doubts I had before hand. Thank you, kindly.

[@himanshunarang4628]

Its simple because this low pressure at polar region is at high tropospheric level as there is intense high pressure due to low temperature at polar surfaces and vice versa.

[@goldfishy]

That area also confused me. It was always my understanding that where the sun heats the ground, you have rising, less dense, warm air, creating a low pressure area. And where the cold air descends from the upper troposphere you have falling, more dense, cool air, creating a high pressure area. Are these low vs high pressure areas a different concept?

[@jabrokneetoeknee6448]

@@goldfishy This is definitely a tricky subject that has also stumped me. I think the best way to grasp this concept is by remembering that "air" is just a volume of gaseous molecules; that "heat" is the amount which these molecules are energized; and that "pressure" is the density of molecules within a particular space. A balloon filled with hot air rises because the molecules inside the balloon are more energized than those molecules which form the ambient pressure of the air outside, and thus the air inside the balloon requires fewer molecules than the air outside to fill the same volume, making it lighter. The key is that the volume of air inside the balloon has expanded to remain at the same pressure as the air outside. However, if the balloon was not allowed to expand from the filling hot air, then the pressure would increase instead of the volume. Using these same principles, molecules in the air outside that have become excited are trapped within the atmosphere and have no volume to expand into, which causes the ambient pressure of the outside air itself to rise.

[@BarneyLeith]

Fascinating!

[@michaelmoran2022]

Superb explanation 👍👍

[@sionnachog894]

A good effort at explanation, it is not easy to understand even with such good graphics and explanation. I'm still not sure if I really get it? I am like the Coliolis, a bit slow to catch up!

[@crystallily9437]

Interesting facts

[@Ayranochfan1]

Superb. Are there any estimates on the period between high and low pressure following eachother at a specific location?

[@solapowsj25]

Does the atmosphere focus light and heat 🔥energy in specific regions like along the tropic of Cancer and Siberian regions? Does cool air rush from the frozen Russian lands to the tropical and subtropical regions as the direct sun rays move toward the South in October and following months?

[@geralldus]

What effect does the reduction in temperature difference between the equator and the poles have on the stability of the jet stream?

[@ArnoldAfleck]

It gets weaker and wavier or stronger and more stable if the temperature difference is higher

[@germantobon5498]

There’s gotta be an easier way to explain this

[@khanyisaninondaba1069]

For real for real though 😭😫🤞🏾

[@potatoesandchips6249]

can i ask if there's a part 2 of "What are the Gas Laws?" thank youuuuu!!

[@MetOfficeLearnAboutWeather]

Apologies for the delay, you can now find part 2 here: kzbin.info/www/bejne/pobLi4qHoNCHp7s

[@potatoesandchips6249]

thank you very much!

[@shabistayildiz6259]

why the coriolis force higher at the exit point than PGF or vice versa why at the first place PGF greater than coriolis force?

[@stephensnell5707]

It's called the Coriolis Effect not force

[@kevintraynor4508]

Can anyone tell me ,where should the jet stream be positioned in May: South or north?

[@adityasengupta582]

It will be northward during summers in the northern hemisphere.

[@Eleventhearlofmars]

If you’re in the uk you want it high up above the country for warmer weather to arrive usually an Azores high pressure system for sunny warm weather.

[@boxthorncutter2804]

Don't understand most of that but ok, thanks.

[@frankmartin8471]

The background music noise is extremely annoying,

[@Darryljohns77]

It's distracting from what requires careful listening. I think they should lower it right down.

[@stephensnell5707]

​@@Darryljohns77it isn't distracting at all,people just say that to complain about the Video

[@alkaholic4848]

Love the vid but that background dum dum dum dum dummm is a bit annoying

[@stephensnell5707]

It isn't annoying,it is absolutely fantastic