It looks like now that the shear is reducing, with the lopsided convection, it is starting to oscillate a bit. I don't know if it was tilted a bit from the SW shear, if the LLC is going to reform under the curved band of convection (I kind of doubt that) or it is just trying to get lined up vertically. Or maybe it is moving in response to that weak upper low Clark mentioned.

Anyway, now that it appears it is about to make it past that trough (which wasn't too certain last night) I was surprised that they kept the forecast to 55kts for the next 24-36 hours...maybe they're just waiting until this aft to see if the trough splits, before increasing the intensity forecast. We can assume because Zeta's a hybrid, slightly cooler water temps won't affect it too adversely, and with the lower shear, it's likely going to intensify. Right now I don't see any reason it couldn't make it to say 75-90kts for a short time, if it gets in the right spot. But I don't know so much, so maybe Clark or HF will post more reasons pro or con with regards to the extent of possible strengthening over the next day or so.

Edit--

The quikscat link is back. 1742 UTC showed Zeta not that strong at the surface, centered at just about 23N41W, which seems a little odd. Guess it really did oscillate around.

Zeta's convection is almost all sheared off. The southernmost part of the TC is close to an area of 40kt of shear, dropping off to around 20 kts just north of the center, coming from the WSW. Instead of enhancing the convection, shear from this direction pushed it away, possibly because this air was drier or coming from a different height (possibly higher?).

However it is very close to an area of low shear that is approaching. Now it would benefit Zeta to more a little further north, but it looks like since Zeta weakened it is being steered WSW by the lower level flow. We have seen hybrids can survive w/very little convection. Zeta should be sticking around until the lower shear moves closer, or it gets an opportunity to move further north, where it will be able to strengthen.

Since Zeta's convection was enhanced by shear yesterday, and destroyed by shear today, it is clear that height and direction (and perhaps humidity level) of the various levels of shear are critical to an intensity forecast.

Got the 2006 signature going
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