FLHurricane.com: Tropical Depression 24 Forms in Western Caribbean

Good points...can I just add something?
I'd be real weary of biting onto any left adjustment (not that you are of course). The reason why she's shifted in the models (in my opinion) is because Pre-Wilma is a weak entity. She's very susceptible to slight perturbations in successive runs, regarding the nearer term.. Sparing the physics to describe, which will just give us all unnecessary headaches...it's sometimes tough to rap our minds around the concept that t-cyclones behave like a log floating in a river.. The heavier the log, the longer it takes to change the direction of its drift/momentum..

Although path of least resistance is always taken by these systems, if more momentum is stored and providing the counter current isn't too overwhelming (causing shear and such), they do need time to respond. That is why a strong hurricane (a heavier log), will often slow down or even stall completely before resuming a new heading; i.e, while their momentum in a given vector is exhausted. Pre-Wilma is a twig with virtually no momentum - only needed a slight variance in the ridge strength anticipation and she's summarily shunting west, and if those influences were already verifying, she'd certainly verify that way. (we are still talking about the prognostication)

However, in the long run she'll be stronger and the righter course is preferred. I'm fairly confident once she's established herself in truer form, the models will re-establish a righter course....probably sooner once they latch onto a her as a stemwinder. And, a lot of that is timing because the westerlies will be in the beginning stages of change right about the time she gets a social security number from the weather gods.

The fact that the runs are unanimously shifted left may be a bit disconcerting for NNE track enthusiasts.

However, I looked at it...we're talking all of a paltry 3-5dm so it is natural that a weaker gyre would be prone to wobble in track guidance accordingly to such small ridge tweaks... My personal experience in watching these things, if she bombs overnight and has a really strong vertical profile, she'll thumb those ridge ripplets in the model runs thereafter, and their track guidance will easily shift back right; notwithstanding that the climatalogical course for all hurricanes tend to have a right bias given enough time; notwithstanding the synoptics slated to evolve. (not saying she'll bomb of course). The upshot here is that the changes in the westerlies that are expected to impact the area with an opportunity to move her N and NNE, will also effectively disallow too too much left motion...

I was surprised that she did not really take off today... She's got very impressive U/A mechanics working in her favor and copious upper oceanic heat content to feast on... The reason after deeper eval is that she's got most of her convection in her outer bands and these are not allowing convergence to maximize coriolis driven angular momentum to her core; as the convective ingest only spirals a small distance before ascending... That is actually important because some of the ingest by the cyclone is actually being pulled from all directions, which is a disruption to centricity.. (Don't bother; it's not readily observable by sat. I've deduced this from the 5pm discussion and what I've learned in college). But, I have noticed a small but intense sub- -70C cloud top region very near the perceived axis of rotation so we may actually be on the threshold of an implosion - so to speak...

Correction: the perceived axis of rotation appears to be NE of where the current impressive, albeit small area of very intense convection is occurring; should this persist inside the large circumvellate, I suspect if possible we could have a center refix...

Edited by typhoon_tip (Sun Oct 16 2005 10:19 PM)

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