Hurricanes are giant engines made of air that are driven by the transfer of heat from the sea surface to the top of the troposphere. The greater the difference in SST (sea surface temperature) and higher altitude temperature, the more power in the engine. But, there are some very strong wind currents in the atmosphere above the troposphere, and that matters as well.
When you fly in a commercial air liner over a long distance, sometimes (depending on the airline) they display a chart that shows current location, speed, etc. as well as outside temperature and sometimes windspeed. You see some pretty remarkable numbers up that high, above the Ozone Layer. If the sea surface temperature is 27 degrees C and the at 8 km t is close to -40 C, that is a lot of temperature differential across the area covered by a hurricane.
However, high winds in the upper atmosphere will interfere with this process. This is why hurricanes don’t really form farther north (in the northern hemisphere) than they do. Too much upper level wind activity. This ‘wind shear’ causes the beautiful turning engine that drives itself pumping heat upward and outward to get all messed up.
Right now, Ike is experiencing some wind shear and will weaken over the next several hours. However, that will go away and other factors will contribute to a re-strengthening.
But where is Ike going to go? Where will it make landfall?
It looks like Ike is going to turn northwards as it approaches the US. This entire time it will be scraping the Leeward Islands and the Florida coast with winds and surf, but how bad that will be depend on the exact track.
Ike is going to be a cliffhanger. The entire predicted track has the storm over waters warm enough to keep it running until it reaches, should it stay in the Atlantic US East Coast littoral, until South Carolina. But there are blobs of mcuh warmer water here and there that may crank it to a higher level as it approaches Florida. But wind shear will also increase as it goes north. I think the Hurricane Prediction center is more or less thinking that Ike will stay in the Atlantic and if it makes land fall, do so on the US east coast north of Florida. But it could just make a lot of wave and rain action and head out to sea.
The soonest that this storm could affect the US coast directly in any significant way is probably mid week next week.