As the jet stream is a main driver, does anyone have analysis going back a number of years on its behaviour.
You cannot look at one year in isolation but over a period is it:
More intense than previous periods. May suggest where everything gets pushed more east nowadays, even thunderstorms.
Does it kink more than usual, or flatline more.
By latitude, is it generally running higher now. May suggest less cold spells.
Originally Posted by: Phil G
The jet stream over the last three months has been adjusting around the regular waves of warm air advection northwards and cold troughs pushing southwards, towards the ESE direction, where low pressure can develop to the SE on the continent. This allows space the the north for high pressure to develop and for cold air advection, for us, from the east. The principle driver for this is higher pressure to the NW of the Azores. All this is generally different to the NE direction of the jet over the last 30 years associated with the Azores High extending NE into Europe.
Nothing is guaranteed but opportunities for easterly outbreaks are, with these synoptics, increased and the models have picked upon this.
Your question is very relevant.
The jet direction over the North Atlantic, is not just related to the position of the Azores High but to its behaviour around the whole of the N. Hemisphere and decades ago, the number of Rossby waves was identified by some climate scientists as being highly correlated with the general synoptics at our general location.
The relevant questions for the longer periods of time you identify, might well be -
What causes the positional changes to the Azores High?
and
What causes the changes to the numbers of Rossby waves?
and...........
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