SE U.S. (Frances) Surface Analysis with Radar Overlay

[wxman57]

Just did a 12Z surface plot and overlaid radar data across the southeast U.S. Surface data suggest that Frances remains a very disorganized minimal TS with about 35kt max winds. Those winds are not near the center, but in the feeder bands east of the center. Buoys indicate that winds decrease from the feeder bands inward toward the center. This structure is more like a non-tropical low. Without a central core, Frances will have a hard time strengtehning in the few hours left before the center moves ashore. Storms like this typically require days to recover. Also, note the mid 60s dewpoint air flowing off the FL Panhandle into Frances. That's not favorable for development.

The good news for the FL panhandle is that there will be no significant wind when Frances's center moves inland. Beaches may see some 35-45 mph sustained winds in the feeder band east of the center with higher gusts in squalls. Storm surge will be nonexistent, for the most part, but the 35kt onshore wind along the western FL Peninsula may increase tides to a couple of feet above normal.

Even though Frances is now a shadow of its former self, it will still be able to produce very heavy rainfall today, though not necessarily near the center. Convergence areas will be the feeder bands east of the center, like the one streaming into Tampa.

What puzzles me is why the NHC is insistent that Frances will become a hurricane in a few hours. That's just about impossible with no central core of convection. Recon winds will not be representative of surface winds with a system like this. Upper-level winds will not carry down to the surface very well at all. Clearly, all surface observations indicate only 35-40 kts in areas removed from the center. Just another case of their "course of least regret". This is what happens when a forecast is based more upon politics than sound meteorological data. Such political forecasts don't necessarily server the public very well. And they certianly make my job in convincing our customers that Frances isn't going to become a hurricane more difficult.


<img src="http://myweb.cableone.net/nolasue/frances2.gif">

[PTPatrick]

I dont know about whether this will be a hurricane or not, but I have to disagree with the surge issue. Wakulla and Franklin counties are very vulnerable to surge. And even though this big storm may not be that strong, a little surge 2-4 can cause a lot a trouble. In fact, this storm is much like isidore was after she left mexico, large and spread out, and even though she went into Lousiana, we had a surge here near the AL/MS line that forced us to have to evacuate(we were trapped by a surge of 4 feet).

[Thunder44]

I agree with this. Although I think the winds are probably near 50mph with higher gusts, in thunderstorms. The center has become more broad. Last recon vortex message indicates the pressure has risen to 982. I don't think it will become a hurricane again.

[wxman57]

I dont know about whether this will be a hurricane or not, but I have to disagree with the surge issue. Wakulla and Franklin counties are very vulnerable to surge. And even though this big storm may not be that strong, a little surge 2-4 can cause a lot a trouble. In fact, this storm is much like isidore was after she left mexico, large and spread out, and even though she went into Lousiana, we had a surge here near the AL/MS line that forced us to have to evacuate(we were trapped by a surge of 4 feet).

I think it's a question of semantics, here. Without a central core, Frances won't produce a true "storm surge" that moves ashore an hour or so before the center moves ashore (near its center). What it will produce is what's called a "set-up tide". A set-up tide occurs when winds blow onshore over a long fetch and for a long period of time. That long feeder band right of the center will produce winds of 35-45 mph from generally a southerly direction for an extended period of time into the NW penunsula and extreme eastern panhandle. This tidal increase could be 2-3 feet above normal - enough to inundate some coastal areas. But this tidal increase is already occurring, it's not something we're waiting for to move ashore as the center does. It will, however, inch up the coast as the center continues northward and the feeder band is directed farther up the coast.