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I am following climate activist Greta Thunberg's sail to N America from Europe on https://tracker.borisherrmannracing.com/. The model shows a cyclonic storm forming south of Nova Scotia, east of New York on August 26, 2019. The same thing can be seen on https://earth.nullschool.net/. I wasn't aware that this type of storm formed so far north and am wondering why this storm is forming and if this is a rare occurrence that may be related to climate change.

enter image description here

Edit to add: Here is the model of air temperature. It appears to me that the storm forms at the interface between cool air from the north and warm air from the south and that the core is warm, but perhaps someone with more expertise can weigh in.

enter image description here

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    $\begingroup$ the key question is the following - is it a warm core cyclone or a cold core cyclone ? If the latter then it is perfectly appropriate to form at that latitude. On the other hand if it is a warm core cyclone then yes marker for climate change. $\endgroup$ – gansub Aug 25 '19 at 17:29
  • $\begingroup$ edited to add image of the air temperature $\endgroup$ – haresfur Aug 25 '19 at 23:18
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A cyclone is nothing more than a low-pressure system. It can surely form in the North Atlantic; in fact, most low-pressure systems that reach Europe form in the North Atlantic. You are probably thinking about a tropical cyclone, which indeed cannot form that far north. Among others, a tropical cyclone needs high sea temperatures (>27 C), which are usually not present at such high latitudes.

About the present cyclone south of Nova Scotia: I think it is a cold core cyclone, as 500 hPa temperature are lower than in surroundings (which is e.g. not the case for tropical storm Dorian, which is currently east from the Lesser Antilles). Therefore, it's not a tropical cyclone but an ordinary extra-tropical cyclone, which can perfectly form at those latitudes.

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No, it's not normal. Hurricanes and typhoons require sun-warmed seas like the Caribbean or Gulf of Mexico to form, because that's where they get their energy from. When meteorologists talk of cyclones and anticyclones, they are talking about high pressure or low pressure weather systems, not hurricanes and typhoons. Storms can form that far north, but probably not hurricanes, typhoons or cyclones, which are just different names for the same thing. When referring to the mega-storms which devastate tropical and subtropical islands, the terms hurricane (Atlantic) or typhoon (Pacific) are usually used. I don't think the weather system featured in your diagram was a hurricane.

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    $\begingroup$ I am afraid this does not answer the question but I am not someone who downvotes. Extra tropical cyclones can form that far north $\endgroup$ – gansub Aug 25 '19 at 18:21
  • $\begingroup$ We famously had a "hurricane" in southern England in 1987, but firstly, it was slightly short of the windspeed which would have made it a hurricane, and secondly, it did not form off southern England but a long way to the south west. Forming at or reaching England or New York are two different things.. $\endgroup$ – Michael Walsby Aug 26 '19 at 18:53
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    $\begingroup$ I am sorry I do not understand what you are saying. How does it answer OP's question ? That is the only thing I am interested in discussing. $\endgroup$ – gansub Aug 27 '19 at 2:45

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