southern jet stream affecting weather on northern hemisphere

[neiseti]

Hi everyone,

I am not sure how to put that as clear as possible since my theoretical knowledge on the subject isn't that advanced.

My question is if the movement of the southern jet stream can affect the weather patterns on the northern hemisphere at the end of spring? What can cause extreme or unusual movement than normal to the southern jet stream and in what way can influence El nino/la nina?

Thank you.

[Aslkahuna]

By Southern Jet stream I am presuming you mean the Subtropical Jet. Typically during an El Niño, we have a very energetic southern branch to the westerlies that comes out of a split in the flow around 140-160W and tracks across SoCA and the southern US. In doing so, it merges with the STJ and picks up a lot of subtropical moisture. This plus the dynamics associated with the flow results in some very major storm systems that tend to track on a southerly course and which can bring copious amounts of snow to areas that usually don't get that much.

Steve

[neiseti]

Hi Steve,

Thanks for the reply. By jet stream I meant both-the polar and the subtropical one. Mainly my question was focused on the polar one, which If not mistaken is stronger than the subtropical one.

Mainly my question is in what ways can the polar jet stream move or shift in a way that can affect the weather patterns in the northern hemisphere? if it shifts more south can it cause excessive hurricanes/cyclones than normal and affect the hurricane season in the northern hemisphere?

maria

[Aslkahuna]

If the polar jet is suppressed southward, the shear associated with it will result in fewer hurricanes but extratropical cyclones would be more frequent.

Steve