#12966 Postby Wthrman13 » Fri Aug 22, 2008 11:13 pm
Not to beat a dead horse, but I think the term "eye" is thrown around rather loosely, even by many pro mets (someone mentioned TWC a bit ago). The problem is, like so many things (my favorite example is the changing definition of a planet), there is no sharp black-and-white dividing line between when something is an eye, and when something isn't, in many cases. I will say this, eyes in hurricanes and tropical storms (yes, tropical storms do sometimes have eyes) are typically considered to be at least partially surrounded by an eyewall of enhanced convection that contains a radius of relatively stronger winds than on either side of it (i.e. the RMW). In the case of Fay, currently, at least from radar observations (I haven't looked at recon recently), the RMW looks to be pretty far out from the center, a good 80 miles or so in diameter. In this regard, the whole clear area seen on current radar from KTLH could be considered an "eye", but it's so disorganized that I wouldn't go that far. Conservation of angular momentum would dictate that in order for a true eye to form in this case, the current RMW would have to contract inwards due to a tightening of the pressure gradient, which would come about if the central pressure were to drop. Right now the current large-scale circulation associated with the storm is in a pretty balanced state and would require a rapid drop in central pressure for it to do this. I don't see this happening right now.
By the way, in my opinion the "eye-like feature" seen when Fay was crossing the FL peninsula the first time was indeed a true eye. It had a nearly complete ring of enhanced convection surrounding it during a good portion of its trek across FL, and Doppler radar velocities confirmed that there was a RMW co-located with the eyewall.
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