FLHurricane.com: Frances at 11PM

An interesting parallel between 1998 Bonnie and 2004 Frances is that they will go down as two of the most heavily-studied storms during the storm itself in the Atlantic to date. Bonnie had many planes in and out of it all the time as part of various recon flights and field missions (such as CAMEX 4) and as such has been well-studied. In fact, I'm reading a paper on it right now. Frances has had similar flights in and around it and, while the inner-core may not turn out to be as sampled as well as Bonnie, the synoptic environment around the storm has been sampled more heavily than any storm I can recall. In any circumstance, it should be interesting to see papers and research over the next 2 or so years on why the models failed with the ridge around the storm (and thus the forecast tracks).

As another aside, this list has been particularly bad to Florida...and the rest of the basin as well. A friend of mine pointed this out to me -- Allen, Andrew, Mitch, Georges, Charley, Frances -- all storms which came from this list. I'm sure the others probably have similar patterns, but this one is particularly notable.

To go more into my comment about large envelope storms being less likely to intensify near landfall -- the larger a storm is, the longer it takes to spin up. Think of the coin drains you used to see in shopping malls and grocery stores: drop a penny in and watch it go round and round. The smaller the drain, the faster it would move around and faster it would get to the center.

Now, picture a block of air on the periphery of the storm. With a smaller storm, it is going to circulate into the center faster, allowing for faster spin up due to the transfer of additional energy (angular momentum, other quantities I won't go into detail about here due to their complexity...ones which I don't understand either). With a larger storm, it'll eventually get there, but it's got a longer path to get to the center and will move slower around the periphery as well.

Frances isn't going to have *that* much time over the Gulf stream to spin up like that. Some increase is possible, but it should be very modest and in line with NHC projections. Furthermore, the larger circulation means that part of the circulation is going to be affected by the big landmass of Florida a lot sooner than a smaller circulation like Charley was. We've seen the little impacts the Bahamas have had on Frances; now, even once the storm gets to the Gulf Stream, about 20-25% of the circulation envelope will already be over Florida, a percentage that will increase as it nears shore. For part of the storm, its energy source will already be taken away by the time the center gets to the Gulf Stream (and before then, the other side of the storm will still be dealing with the Bahamas). Primarily for these two reasons and partially based upon climatology for these types of storms, that's why a steady-state (or nearly so, as the NHC calls for) solution is probably the best call in this case.

Brief note on TD 9 & 97L - TD 9 should be Ivan sometime tomorrow. The circulation is on the NE side of the convection, or so it appears, but if anything this is going to help it with the fast forward speed towards the west otherwise wanting to tend towards shifting the convection to the east of the center. The GFDL is probably way too high with the intensity, bringing a strong cat 4 hurricane through the central islands in 5 days, but with these deep tropics storms, you never know. Strange how many potential Caribbean storms we've had this year.

97L...it has a shot, but needs to develop some convection over its center. Currently, it's all well-removed to the north and east; it's got to show some better organization soon for it to have a shot. It's one for the fish in the end, and with more pressing matters, that's all I'm going to say about that one unless conditions otherwise warrant.

Okay, I said an hour ago I was going to get some rest -- I mean it this time!

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