Update - Sunday Afternoon
If there is such a thing as good news with regard to a hurricane it is that Hurricane Gustav did not rapidly re-develop his central core after leaving western Cuba in the early hours of Sunday morning. The eye of the hurricane is still ragged and elongated and the inner core has still not fully established itself. Based on aircraft recon, Gustav remains a low-end Category III Hurricane with sustained winds probably closer to 115mph and a central pressure of 960MB. Movement remains generally to the northwest with occasional jogs to the north northwest and the forward speed is currently about 13 or 14 knots.

With the lack of rapid reorganization of the central core and eyewall over the past ten hours, Hurricane Gustav is not likely to intensify very much (if at all) prior to landfall. He has already moved north of the warmer SSTs of the southern loop current in the Gulf of Mexico and windshear has already had some impact on the system. With slightly cooler waters ahead on his track, Gustav will be challenged to maintain a steady state prior to landfall. I don't really anticipate any significant changes in the track - maybe just a nudge to the east which could place the New Orleans area to the west of the track - but still difficult to make a firm call on this given the lighter steering currents in the north central Gulf.

Gustav's forward motion is likely to slow down just prior to or just after landfall, and this would significantly increase the potential for heavy rainfall and flooding conditions in Louisiana and Mississippi - and other areas near and east of the track after landfall. The risk area as outlined in the original article remains unchanged with isolated tornadoes possible in areas north and east of landfall. With consideration for increasing windshear and lowering SSTs, Hurricane Gustav should make landfall as a high-end Category II storm (although a low-end Category III is still possible if the forward speed picks up again).

Regardless of final intensity, every landfalling hurricane should be taken seriously and planning, preparation and protection are the keywords. The storm surge at and east of the landfall area will still be about 10 feet with surge in constricted areas up to 13 feet. Even if the storm should pass just to the east of the New Orleans area, wind driven overwash from Lake Pontchartrain could still cause serious flooding conditions. Follow the instructions of your local and state Emergency Management personnel and stay safe - and alive.
ED

Original Article
Hurricane Gustav has entered the southeastern Gulf of Mexico just off the north coast of western Cuba near 23.1N 83.8W at 11PM. Movement is still to the northwest but the forward speed slowed down a bit as the hurricane made a slight jog to the west northwest and it took him about three hours to cross over Cuba. This was probably a little longer than the NHC had anticipated. The eye clouded over and I'm sure that the intensity has dropped off somewhat, however, the eyewall structure is already rapidly rebuilding. Still looks like a general northwest track through the Gulf, although since the high pressure ridge over the southeast has been a little slower in its development, I'd expect some minor adjustments to the right in the forecast track. My best estimate right now would be a track from its current position to about 30N 90W with landfall Monday afternoon on the Louisiana delta and then near the Louisiana-Mississippi state line as a major hurricane. Gustav may still regain Cat IV intensity in the Gulf, but wind shear and cooler sea surface temperatures in the northern Gulf should lower the intensity again - but not by much. If Gustav moves northwestward in the Gulf with a brisk forward speed, intensity at landfall could still be Cat IV.

With high pressure building over the southeast and Gustav passing well to the southwest and west of Florida, east central Florida will have rapidly moving squalls from the outer bands of Gustav with brief wind gusts to about 35mph Saturday night and Sunday (and perhaps a few Sunday night). The Keys and the Florida west coast may have a few gusts that are higher, but the Gulf coast from western Louisiana to the western Florida panhandle will bear the brunt of this dangerous hurricane. If your area is ordered to evacuate, don't hesitate - just do it! A storm surge of 15 to 20 feet above the normal high water line is possible in the area immediately to the east of where the eye makes landfall.
ED