Second Ridge reloaded now/Gun getting cocked

[John]

Some of you might remember me talking about the second Ridge reloading last week, well this is it. Isabel has been stationary between the departing Trof and Canadian High to her North. high res visible imagery suggests this is about to change quickly. Already the upper steering over Florida is backing to the North rather than the West as has been the last few day's, this is an indication that the leading Eastern periphery of the Reloading ridge is moving in, you can also notice the outflow pattern to the West is much less disrupted now. This is going to get rather interesting soon, it would not surprise me in the least to see Watches Extended a bit further South to include other Parts of SC. Isabel is likely to begin going through another round of strengthening later this evening.
More Later
John

[beenthru6]

So where are you projecting will be the greatest probablility for landfall? Are you not going with the rest who say the outerbanks? thanks!

[bobbisboy]

The 5PM discussion mentioned the possibility of a slight bend to the west of their track. I take it you see more than that ?? Thanks in advance.

[dixiebreeze]

Almost locked and loaded John. I've been saying anywhere from Jax to Charleston north (actually I even said Melbourne, but that doesn't seem likely now). Looks like it's a curtain call for Isabel.

Kudos on your forecasts, BTW.

[dixiebreeze]

Nice shot of her winding up:

http://www.ssd.noaa.gov/PS/TROP/DATA/RT ... VIS/20.jpg

[charleston_hugo_veteran]

John where are ya?? Please give us your landfall prediction :o

[wayoutfront]

Is that a solid eye I see? peeking up at me?

[Guest]

Jacksonville> Melbounre....ummmm NOT

Almost locked and loaded John. I've been saying anywhere from Jax to Charleston north (actually I even said Melbourne, but that doesn't seem likely now). Looks like it's a curtain call for Isabel.

Kudos on your forecasts, BTW.

[wxman57]

John, I think what you are seeing is the upper-level ridge which had been extending across Florida from the Gulf and producing the W-NW flow into Isabel (the westerly wind shear) has been replaced by an upper-level trof that is digging into northern Florida. This trof is now producing moderate S-SSW winds aloft in advance of Isabel. This is enhancing the outflow on Isabel's west side. But I don't see anything there to steer Isabel more westward. There is still a weakness in the ridge north of Isabel. As the trof digs into Florida tonight/tomorrow, and is enhanced by another trof digging into the southeast U.S. by Thursday, Isabel should resume moving NNW then NW toward the NC coast.

That said, I do agree that residents along the lower NC coast have to remain vigilant. Isabel could still move inland as far south as Wilmington. Or, as the second negatively-tilted trof reaches the east coast early on Thursday, Isabel could even track right of the current forecast and hit the Delmarva Peninsula. I think the current forecast track is still in the middle of the two possibilities. But everyone on the east coast needs to remain alert.

Now, the approach of a negatively-tilted upper-level trof could provide enhanced outflow for Isabel tomorrow. That's one factor for pre-landfall intensification. The only negative I see is a big one, however. Look at all the tremendously cool, dry air that has moved offshore and lies across the Carolinas and Virginia. Just a piece of some dry air was entrained into Isabel yesterday and it caused significant weakening. If a large chunk of dry air is entrained into Isabel before landfall, it could knock out much of Isabel's convection in nothing flat. The question is, will the dry air get entrained?

[wxman57]

Take a look at how the storm is oriented on IR imagery now - SE to NW. The cirrus blow-off is concentrating NW of the storm towards Cape Hatteras. That tells you where the upper winds are blowing toward.

[Rainband]

Thanks wxman57 for that analysis

[SacrydDreamz]

WV loop highlighting dry air moving into the Gulf and offshore into the Atlantic. Notice Isabel's size change as well..