The late summer never ends. At the weekend, a weak cold front will touch the northern Alps and bring some cooling, perhaps even a little snow for the optics. Next week, however, the tough November high will return and it will be business as usual for the time being. A onset of winter in the desired sense is not in sight (not even at the weekend).
So let's forget the question "When will it finally be winter?" for the moment and instead deal with this question from German:
To what extent can you predict precipitation in the Alps due to hurricanes on the east coast of the USA? I experienced "Joaquin" and its devastation in the USA this year, followed about 10 days later by the first heavy snowfall in the Alps. Do such weather phenomena always follow the same pattern? Or was this just a coincidence and not a pattern? My guess: when a hurricane is active on the east coast of the USA, it is followed (with a time delay) by heavy precipitation in the northern Alps?
What was a hurricane again?
A hurricane is a tropical cyclone in the Atlantic and is no different from its colleagues cyclone and typhoon, except in name, which just live somewhere else. Tropical cyclones mainly form in a zone between the 5th and 30th parallel, hence the name. Large amounts of water evaporate over the warm oceans here, especially in late summer and fall. If certain other conditions are met, a self-sustaining system can form, at least temporarily, in which new moist, warm air is constantly drawn into a vortex of moist, warm air. The whole thing intensifies as long as the supply is right and weakens when the hurricane hits land, cold water or dry air masses. When tropical cyclones leave the tropics and reach the mid-latitude frontal zone, for example, they can become an extratropical low pressure system. An ex is then simply placed in front of the name. In this case, Joaquin became Ex-Joaquin.
Joaquin
Hurricane Joaquin formed in the last days of September southwest of Bermuda. By the first of October, it had already developed into a category 4 storm. The Bahamas were the hardest hit, where the storm caused around 60 million dollars in damage and devastated entire islands. Bermuda and the Antilles were also caught in the path of the storm. The American freighter El Faro disappeared in the storm with a crew of 33. Joaquin did not make it to the American mainland. However, a normal, non-tropical low pressure system was able to tap into the hurricane's moisture, causing severe flooding in parts of the US, particularly North and South Carolina. Once he had caused enough trouble, Joaquin made his way across the Atlantic. Emaciated beyond recognition, ex-Joaquin arrived in Portugal on October 10. He hung around there for a few days until he was swallowed up by another system over Spain. Only on the coast were gale-force winds reached at the beginning, otherwise there was not too remarkable wind and rain, which gradually spread inland on the Iberian Peninsula. All in all, Ex-Joaquin's visit to Europe was fairly unspectacular, although the low pressure system that finally ate him up did cause some storms in Italy. The short-lived onset of winter in the Alps in mid-October was due to a drop of cold air that had nothing directly to do with Joaquin.
Conclusion
Back to the question: Do such weather phenomena always follow the same pattern? No. Hurricanes from the Caribbean can move towards Europe on very different paths, if they do at all. Our weather is always somehow influenced by the weather elsewhere, sometimes quite obviously and sometimes more on the butterfly wing flapping in China level. It's definitely not a pattern in the sense of "if there's a hurricane over there, I'll start waxing my skis". However, hurricanes can certainly appear in Europe with a bit more ruckus. Last year in October, the remnants of Hurricane Gonzalo caused storm damage and traffic chaos in the British Isles. My guess: if a hurricane is active on the east coast of the USA, it will be followed (with a time delay) by heavy rainfall in the northern Alps? It might happen, but it's definitely not a reliable aid to weekend planning.
