I have a feeling that Dennis will weaken substantially after impacting Cuba. The terrain in central Cuba is somewhat higher (not incredibly significant, though) than in western Cuba (where Charley crossed last year), so the hurricane's interaction with the land should be slightly more pronounced. No doubt Dennis will be a formidable hurricane in the Gulf, but I am thinking only a weak category 2 at landfall (100-200 miles north of Tampa is my guess). I could be wrong, but I really have the feeling this thing is going to bite it after interacting with Cuba. Positively considered, Dennis is moving quite quickly, so his interaction with Cuba might not be that significant.
Also, on a somewhat anecdotal note, I've noticed that hurricanes that are powerful Cat. 4 and Cat 5 hurricanes way out at sea get everyone's attention, and then they promptly die when getting within a few hundred miles of the coast. Then there are hurricanes like Charley that weren't much 36 hours before landfall, but favorable conditions allowed for rapid deepening and a big surprise. I think this hurricane will probably scare a lot of people, but will not do near as much to Florida as it will (and is doing) to Cuba.
Gabe
I agree that big, large storms way out at sea will weaken when approaching land, likely due to the shallower, cooler waters and the usual trough that increases wind shear and introduces some dry air. Look at Ivan, Cat 5 to 3. Similar thing with Allen in 1980 - big Cat 5 that weakened to Cat 3 right before landfall. It's hard to imagine that Lili in 2002 was a 145 mph Cat 4 just 12 hours before landfall. Frances was a Cat 4 at its peak, Cat 2 at landfall. Isabel was a Cat 5, but it choked and it made landfall as a weakening Cat 2. It seems that most times a strong 'cane hits the U.S. (look at Andrew, Audrey, Charley, Jeanne, 1935 Labor Day Hurricane) it's a small hurricane that rapidly intensifies right before landfall.
But then again, Donna, 1938 Long Island Express hurricane, and Hugo were hurricanes that remained strong.
Still, Dennis has its weaknesses that will likely be crucial near/at landfall. One is climatology does not support Dennis (after all, it's only July). Two is the dry air in the GoM, which right now is already impeding Dennis. In fact, Dennis looks like it will be downgraded to Cat 3 in the next advisory. Three is land, which is also helping the weakening of Dennis. And look, with the look of Dennis on satellite, it can't do well over the more mountainous terrain of central Cuba.
At this point, Dennis should not pull a Charley. The surface trough off the west coast of Florida and the mid-upper ridge over the state should act as a mild buffer. If it does turn, I would be very surprised. However, paralleling the coast is a different story.....it could possibly happen if the trough is aligned NNW-SSE in that direction. We'll have to see after analyzing surface obs in the morning.
There is a possiblity that a trough could temporarily strengthen a hurricane by enhancing outflow. Look at Charley and the 2005 Karl. Both storms strengthened as the trough enhanced outflow right before they weakened as the trough increased wind shear (or in Charley's case, land). However, I still think Dennis will not be a major hurricane because of the negative land interaction with Cuba, its large size, and the less Hurricane Heat Potential.
But then again, it could survive Cuba, and in that case, we might have something to watch out for.
I was aware of the NHC site, I just didn't know if there was a Public Advisory or recon that I hadn't read that had upped the intensity to 150 mph. The 8:25 am public advisory read "...INDICATING A SURFACE WIND OF AROUND 140 MPH," so I didn't know if this had been adjusted or not. (I hadn't seen the 11 am advisory)
