It's quite amazing, really. A scant 24 hours ago, I was speculating that then 'Invest 97L' might be on a sort of 'fast-track' for development into a tropical depression, or perhaps even a named storm, within a day or so. But even I didn't anticipate the striking developments that have transpired overnight and throughout the day.
First, to have a significant tropical storm already waiting for the recon mission to arrive, and then for recon to find an already-developing ragged-type 30-mile-wide 'eye structure' speaks volumes for the still-not-well-understood process of tropical cyclogenesis and the dynamical considerations promoting and leading to rapid intensification. There is still much challenging research work to be done here in this regard, and is personally for me one of the most interesting and fascinating aspects of the tropical cyclone life cycle.
From this recent animated visible satellite loop, taken just before sunset, shows a still steadily strengthening tropical storm with an expanding tropical storm force windfield and convective banding features becoming more pronounced in the NE Semi-Circle.
And if you look *closely*, you may notice a sort of 'dimple' (just below 12N), near the supposed center of circulation, just below several large thunderstorms, which to my partially trained eyes looks to be the harbinger of an eye, though as yet still cloud-filled.
And from looking back at passive microwave imaging from the last 12 hours or so, one can also see a nascent eye and eyewall feature developing in the inner core convection as early as 12 hours ago, presumably co-located with the ongoing sucessive bursts of very deep convection as displayed in the infrared and water vapor animated loops.
Note that these 2 images were taken just over 12 hours apart, at 7am and 7pm EST and note, as well, just how much the system *has* moved in that time. The inner core convection now appears closer to the coastline.
As Bloodstar was commenting earlier ...
Not every day you see an eye in a relatively weak tropical storm. I suspect we're going to see some pretty rapid intensification with this storm. Which will really throw any model runs off.
The storm isn't really moving much either, so even though it's relatively close to land, it's not going to be severely impacted by the proximity for a while.
I think Ida will be a hurricane. And sooner than people would have expected.
I would certainly have to go along with that rational, although as just mentioned, it is noticeably closer to Nicaragua than 12 hours ago.
On the other hand, as Mike notes ...
If Ida deepens rapidly, it would lean more toward a northward motion than west, if it weakens it would likely go more west.
Yes it's true that, all other things considered equal, a deep and well-developed storm will tend to display more of a northward component than a shallower system which tends to be steered more westerly by the low-level easterly flow it finds itself in. Unless, of course, it's being driven by a deep layer ridge to it's north, as was the case with Major Hurricane 'Felix' a few years ago, for example, which was driven due west across the entire Caribbean Sea.
But a deep layer ridge to the north is nowhere to be found in this case, and what weak steering currents that do exist would tend to impart more of a northerly-ish track, should the storm continue it's current explosive intensification phase a deepen even further, resulting a larger and more substantial tropical storm force windfield.
In all likelihood, it seem that an oblique landfall to the coastline as a hurricane may well occur, but at just what angle, how far up on the coastline, and the degree of northerly component it's acquired by that time, and of course it's forward speed under still weak steering currents, will be the determining factors as to the length and duration 'Ida' will be over Nicaragua/Honduras before emerging into open waters to it's north.
In this recent color-enhanced IR image from the University of Hawaii's Weather Server, you can certainly notice the huge blowup of very deep, bursting convection over the LLC, resulting in an impressive CDO, but also quite apparent is the proximity of the storm to the coastline.
6 Hour Animated Color Enhanced IR Loop from the University of Hawaii Weather Server
Again, with the hearlding of tonights' convective max cycle, it should be very interesting to see if 'Ida' continues to rapidly intensify, and if so, just how much this actually 'turns' the storm to the north.
Even 10 or 15 degree variance to the right of it's currently forecast track would mean much less time the LLC will be over land, and more significantly, also means that the bulk of the storms' circulation will remain over very warm water, which would help the storm to retain it's organization better and likely result in a stronger system as it emerges off the coast of Honduras in a few days time.
Edited by CoconutCandy (Wed Nov 04 2009 09:53 PM)