User:LightandDark2000/Cyclone Stephanie (2016)

The September 2016 Bay of Biscay cyclone, also named Cyclone Stephanie by the Free University of Berlin, was a rare and unusual extratropical cyclone that formed in the Bay of Biscay in the middle of September of 2016. Forming from the tail end of a cold front that was located in the far northeastern Atlantic Ocean, the nascent system drifted southeastwards as it began to undergo occlusion. The cyclone eventually reached its peak intensity on 15 September, before coming ashore near the Spain–France border, rapidly weakening, and later dissipating on the next day.

Although the system itself didn't cause a lot of damage (with the exception of producing gusts up to 130 km/h, heavy rain and some minor surf in the affected areas), it gained a lot of media attention from meteorologists particularly because of its resemblance of a subtropical cyclone, which the foreign meteorological service Météo-France claimed it was, due to its apparent eye feature and nearly separating completely from its parent extratropical cyclone. However, no other meteorological services classify it as a tropical or subtropical cyclone, mainly because surface analysis from NOAA and other agencies still showed fronts attached to it. Furthermore, the National Hurricane Center did not name or monitor the system, due to the disagreement over this storm's exact nature.

Meteorological history


On 12 September 2016, a cold front was draped across the Bay of Biscay in the far northeastern Atlantic. Over the next 12–24 hours, a non-tropical area of low pressure formed along this front and began to condense into an extratropical cyclone, which the Free University of Berlin named Stephanie. By September 14, the newly-developed low was situated in the northern portion of the bay. Situated over sea surface temperatures just near the minimum threshold to sustain tropical cyclones – around 23 C, the low intensified and began to obtain some characteristics resembling that of a subtropical cyclone, however there were major discrepancies among meteorologists regarding its classification (see below).

By 18:00 UTC that day, the cyclone began to drift to the southeast towards the border of Spain and France. The storm continued to the southeast, eventually intensifying to a peak intensity of 998 mb early on 15 September, corresponding with an eye-like structure visible on satellite. As it neared landfall, the storm began to weaken, and by 00:00 UTC on 16 September, the cyclone made landfall along the Spain–France border with a central pressure of 1004 mbar. Land interaction quickly took its toll on the system, and the cyclone was absorbed by another tropical system east of England, by mid-day on 16 September.

Impact
The cyclone brought only minor damage to Spain and France, most of which were caused by some strong wind gusts, swells, and some heavy rainfall. Maximum gusts of up to 130 km/h were reported on the coast of Basque Country, with slightly higher gusts in the upper elevations. A storm surge of 3–4 ft was also reported on the coastlines of Spain and France. No major damage, fatalities or injuries were reported as a result.

Discrepancy among subtropical status
The storm's nature was mainly disputed in how it was officially classified. Météo-France, which is the official French national meteorology service, released a statement on 15 September claiming that the system was a subtropical cyclone – meaning it had characteristics of a tropical and extratropical cyclone. This was met with major controversy, as many American meteorologists made the claim that the system was in fact extratropical, as proven by surface analysis data from NOAA, which showed that the cyclone still had an occluded front connected to it – signs that usually indicate an extratropical cyclone.