I was really interested in HF storms a while back. There are actually a dozen or two HF (hurricane force) extratropical cyclones each year, with most allegedly coming out of the mid-latitudes. January is their climatological peak for the North Atlantic. Interestingly, observations show that the storms are stronger pressure wise in our basin than in the North Pacific. I still don't really understand all the meteorology associated with them, but (correct me if I am wrong) they are defined by an extreme temperature gradient that surrounds the low. Hurricane conditions are always found to the immediate south (the ‘cold’ side) of the secluded warm center, and are generally not far removed like we are used to thinking. To accent on Dave's comments, if you are interested, do some research on the 87' England storm, which is probably the most infamous. They are difficult to forcast, and alot of people were caught offguard.