....Ran into an answer much like yours, which of course means it depends where you are.
Yup...however, I think for most of those of us who are worried about hurricanes, we are mostly concerned about latitudes from about 25 N to 35N, where a good rule of thumb would be 'about a mile' per minute of travel. It'll get you close unless you are doing precision calculations....then you have to really know your math to compensate for Latitude changes....
-------------------- Richard
A forecast is NOT a promise!