Ike makes landfall on Cuba...

At about midnight local time, Ike make landfall on Cabo Lucrecia as a Category 3 hurricane.  It has since tracked westward across the island, and has recently exited just north of Gulfo de Guacanayabo as a minimal Category 2 hurricane.  Over the coming day, it will pass along the southern length of the island, then cross back over Cuba where Gustav did as a Category 4 storm less than 2 weeks ago.  Then it'll have about 4 days in the Gulf of Mexico prior to a US landfall.

As of 15Z, Ike is an 85kt hurricane, with a central pressure of 960mb.  It's heading W at 12kts.  The storm has lost the majority its deep convection, and the inner core has been disrupted.  It should be able to reorganize quickly over the very high oceanic heat content on the south side of Cuba.  The latest forecast track indicates a Houston landfall this weekend as a major hurricane.  However, 5-day forecasts have an average error of 220 miles, so don't focus too much on the exact forecast track.

Once exiting Cuba, the Gulf will be the factor in how much Ike will reintensify.  Ike will cross over the Loop Current, a deep warm patch of water in the east-central Gulf.  After that, the northern Gulf shelf waters are warm, but not very deep.  In the following two plots, you'll find the sea surface temperature (a "skin" temperature), and the oceanic heat content (an integrated energy content from the surface down to the depth of the 26C isotherm).  As you'll see, the surface can be warm, but if that warmth doesn't run deep, a strong hurricane can stir up cool waters quite easily and weaken.  The exception would be storms that are moving fairly quickly... they may stir up cooler water, but they're already past that patch of cooled ocean by the time it would have an influence.
http://www.aoml.noaa.gov/phod/dataphod1/work/HHP/NEW/2008251gosst.png
http://www.aoml.noaa.gov/phod/dataphod1/work/HHP/NEW/2008251go.jpg

Taking these and other factors into consideration, here is a plot of the MPI, or Maximum Potential Intensity, which I described in Sept 4th's update.
http://wxmaps.org/pix/atlpot.png

Please visit my tropical Atlantic headquarters.