Usa East

Home > GPS > Usa East

April 29th, 2008 admin Leave a comment Go to comments

What proof is there that we say in the UK that we usually get the remnants of the USA East coast weather?

Are there satellite images or video clearly showing the movement of eastbound weather systems from the east coast USA over to the British mainland? It’d be fascinating to see it to know if it was true or not

It works like this: The North Pole is cold. Cold air sinks and creates a region of high pressure. Between that and the sub-tropical belt of high pressure, there is a front of air masses of different temperature. This is the polar front discovered by the Norwegian Bjerknes in 1918. On the top of it, the tropopause makes a kink because of the sharp difference between the two air masses. Along that, a spinning stream of air appears. This is very similar to a tornado, actually, but this one is horizontal. It is called the Jet Streams. Because of the earth’s rotation and the Coriolis effect, it moves to the east.

Low pressures created by the warm air rising over the cold one along the front, also move eastward, taken by the Jet Streams. It brings low pressures from the east coast of the US toward the British Islands at an average speed of 20 to 25 knots.

Roughly three times per year, the Jet Streams get so weak that they are barely noticeable. When it happens, it is not unusual that a stationary high pressure builds up over northern Europe. It may happen in June, September and December. But, otherwise, it is a succession of low pressures, followed by a high pressure ridge, then a new low pressure, coming from the west. That is the usual weather pattern at our latitudes.