Historical Humberto

"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." 

UPDATE: The Seablogger, never shy about the weather, has an idea.