Where do our low-pressure systems end up?
weather@saltwire.com @allistercanada
After a storm system passes through the region, do you ever wonder what happens to it?
Where does it go? Does it dissipate?
Leslie Dubinsky was curious if recent storms that hit Europe were the same or remnants of storms that had previously impacted Atlantic Canada. She asked if large storms can sustain themselves well out into the Atlantic Ocean and onto Europe.
They most certainly can, Leslie. In fact, the recent storms that have barrelled through parts of Europe were either previous low-pressure systems that impacted parts of Atlantic Canada or formed in the same trough of energy that was once over Atlantic Canada.
Where a low-pressure system tracks depends on the jet stream. The jet stream is fastmoving air currents, often with troughs of low-pressure and ridges of high-pressure. These fast-moving winds are eight to 15 kilometres (about twice the height of Mount Everest) above Earth’s surface and move our weather systems. The placement of these ridges and troughs in the jet stream determines where low-pressure systems go and, of course, most that pass Atlantic Canada make it into the North Atlantic as most of our weather systems move in a west to east direction.
Most mid-latitude cyclones develop along boundaries between warm and cold air masses. Mature low-pressure systems will develop warm and cold fronts. Once the cold front overtakes the warm front, it cuts off the supply of warm, moist air. This allows the low-pressure system to gradually dissipate.
Allister Aalders is a weather specialist with SaltWire Network. Reach him at allister. aalders@saltwire.com