Hurricane Felicia has weakened considerable since this time yesterday.
Overnight, the inner eyewall convection weakend, as suggested by the warming cloud top temperatures and a steadily contracting central dense overcast feature.
Also, the eyewall convection became rather ragged looking and several passive microwave images during the night revealed an open eyewall to the NW and all the deep convection (red reflectivities) was, for some reason, shunted into the E Semi-Circle.
Passive Microwave Image of Hurricane Felicia Overnight Showing an Open Eyewall to the NW and Lopsided Convection in the E Semi-Circle ...
However, since that time, convective trends have increased once again, beginning with a large spiral rainband developing, with deep convection, in the Northern quadrant ... roughly the same side as the exposed and still open eyewall.
Microwave Image a few hours later with a Large Spiral Rainband Developing in the Northern Quadrant, roughly 7AM Hawaii Time, (1PM Florida Time).
Moreover, since sunrise (again, local basin time) it's readily apparent from both animated visible satellite loops and color-enhanced IR imagery that a large convective bloom has erupted within the inner-core convection processes, once again igniting powerful updrafts and sustaining deep, bursting convection with cloud top temps exceeding -80 C.
This deep convection has rapidly wrapped around the large 30-mile-wide eye that Cat. 2 Felicia is still sporting, dramatically deepening and widening the eyewall structure, all the while the CDO signature is once again expanding in all quadrants to give the overall appearance of a much stronger hurricane than last night!
This a 4 1/4 hour visible loop, ending 1PM Hawaii, about a half hour ago. You can easily see the eyewall rapidly evolving from a small, ragged structure in a larger and stronger feature, with the deep cold tops totally wrapping around the entire eye once again. Also apparent is the simultaneous blossoming of numerous spiral rainband structures, as if the evolving eyewall dynamics had 'triggered' this development on the perhiphary of the cyclone, or vise versa.
And here is yet another Passive Microwave Image *just out!* that tells the story of a stronger, bigger, much better organized tropical cyclone. I'm no expert, but this is decidely *not* the hurricane we had last night!
So, it seems to me, IMHO, that Still Powerful Cat. 2 Felicia is attempting one last 'Hurrah' and, despite less than optimal SST's is never-the-less managing to hold it's own and even to perhaps strengthen just a tad more yet, before her appointed destination with the impending, quashing upper-lever vertical wind shear in a few days time.
It's also interesting to note that there is more spread in the model guidance during the time Felicia will be coming into Hawaiian Waters ... the GFS has been consistant with bringing Felicia directly over O'ahu for the past 2 days, tho it seems that the NHC forecasters are discounting it in favor of the newer 'super-hurricane' models that have evolved over the past few years.
It's worth noting that a somewhat stonger system, with some remaining deep covection, (as opposed to a shallow system, completely devoid of deep convection), might tend to stay on a slightly more Northern track, as it would not be as influenced by the low-level tradewind flow, as would a more shallow sheared system.
Obviously, these developments bear close watching, and my surmise is that the 5PM package (Hawaii !!) may not be quite as rosey as was yesterday's philosophy.
Another interesting development is that a highly specialized aircraft has arrived in Hawaii and is flying at very high altitudes in the vacinity of Felicia and taking detailed instrument measurements to relay back to the NHC and also to the Central Pacific Hurricane Center (CPHC) here in Honolulu, who will take over responsibility for tracking and forecasting tropical cyclone Felicia, once she crosses over 140W sometime on Saturday.
Finally, the 53rd Weather Squadron, the 'Hurricane Hunters' will be flying out to Hawaii and arriving here on Saturday to begin making numerous flights into Felicia as she makes her approach towards the Islands.
More coming soon ....
Edited by CoconutCandy (Fri Aug 07 2009 08:35 PM)
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