A Hypercane is a hypothetical class of extreme hurricanes which are much larger, taller and posses greater wind force than any hurricane presently possible. A hypercane could form if ocean temperatures reached around 50° C (122° F). Present day hurricanes are rated up to Category 5 on the Saffir-Simpson scale with wind speeds up to about 200 mph (320 kph).
In 1988, scientist Kerry Emanuel performed computer modeling on hurricanes formed by even higher water temperatures than are available today. With ocean surface temperatures above 113°F (45°C), Emanuel modeled larger storms with peak wind speeds of 492 mph (792 km/hr) which would create higher waves and storm surge than are seen today as well as much greater wind damage. Remember that a doubling of the wind speed increases wind force by nearly eight times (proportional to the cube of the velocity) . Froede notes that modern day hurricanes have stirred as much as 100 million cubic meters of ocean floor sediments, with resulting large inland deposits. A Hypercane would stir much more sediment from the ocean floor.
Creationist models of post flood oceans include places where the sea water temperature would be high enough to allow these storms. Secular scientists consider hypercanes possible at certain times in the earlier ages of earth.
Carl Froede reasons that deposits found in the southern USA are best interpreted as tempestite evidence of an extremely large storm. He believes that the hundred mile width of the deposit, its thickness, and its sedimentary composition point to deposition by a very large storm. He notes that the deposit does not have the indications that would result from a series of normal storms. Froede says "I believe that the hypercane passed over this submerged portion of southwestern Alabama during the Middle Flood Division, moving toward the north-northeast. Extensive subaqueous and subaerial volcanism in western North America, Mexico, and possibly Central America could be a probable oceanic heat source that generated one or more hypercanes during this time interval."
- A Hypercane Deposit at Little Stave Creek, Clarke County, Alabama, USA by Carl R. Froede, Jr. CRSQ 44(4):286-300. Spring, 2008.