From forecaster James Franklin:
BASED ON OPERATIONAL ESTIMATES...HUMBERTO STRENGTHENED FROM A 30 KT DEPRESSION AT 15Z YESTERDAY TO A 75 KT HURRICANE AT 09Z THIS MORNING...AN INCREASE OF 45 KT IN 18 HOURS. TO PUT THIS DEVELOPMENT IN PERSPECTIVE...NO TROPICAL CYCLONE IN THE HISTORICAL RECORD HAS EVER REACHED THIS INTENSITY AT A FASTER RATE NEAR LANDFALL. IT WOULD BE NICE TO KNOW...SOMEDAY...WHY THIS HAPPENED.
Well, that's blunt enough, no? I'm not entirely clear on what Franklin means, though--the record hinges on "near landfall", I guess. Obviously there has been more rapid strengthening over the open ocean. Perhaps he's saying that what we've observed with Humberto is particularly scary because it suggests that more rapid intensifications may occur just before a storm strikes land than previously thought possible.