I was just about to agree with you completely before quickly checking via google It certainly seems odd that after all this time nobody would have been able to identify the precise reason for the deepening Unfortunately though the best explanation I ve been able to find is here It seems that not even the Met Office has an explanation on the site beyond simply saying that it originated in the Bay of Biscay and then deepened Whether Floyd had anything to do with it is quite questionable being speculative as it is and the assertion may have its roots perhaps in the popular mix up of the two storms at the time Being at the ideal position at the Jet Stream though seems like a plausible explanation The above link at least contains a link to satellite images from formation to dissipation I guess the only way to know for sure with regards to the relative position of the Jet and the Low would be to look up archived charts for that period something I don t have immediately available All in all I think it right that the section should be disputed though I don t know if it s nessecarily incorrect