caused when warm air aloft ends up on the northern, cooler side of thejet stream. It’s a very stable pattern that tends to not budge for days. It gets its name from its appearance on upper-air wind charts that steer winds around the lows and highs in the shape of the Greek letter...
(to the south). Because the behaviour of air currents is determined by the interaction of the Coriolis effect and the pressure-gradient, the Right Entrance and Left Exit regions of jetstreaks are areas where winds aloft diverge, allowing air below to rise. This in turn further encourages ...