Well, it's the Upper-level shear to the rescue, once again. Our 'prayers were answered' and the forecasted shear finally showed up, but only after Flossie put on quite the impressive show as an extremely potent, compact, steady-state, annular Cat 4 Hurricane for over 36 hours, all the while steadily approaching the Big Island for days.

But all is not said and done with quite yet! Far from it. We're certainly not 'out of the woods' yet. Read on ...

While the SW shear did in fact arrive, and is estimated at 25 kts. at 6am Hawaii time, it appears to me that it's not the kind of shear that will rip a hurricane apart in 12 hours. Far from it.

In fact, is you closely study the animated IR and visible satellite loops and, more recently the animated short-range and long-range NEXRAD loops from the Doppler radar located on the SE flank of the Mauna Loa volcano on the Big Island, you'll notice very busy eyewall activity, albeit not quite closed in the SE quad. I'll get back to the continuing eyewall evolution in a moment.

But if you look at these animated satellite loops, you really can't help but notice the cirrus being blown off in all directions, directly from the central eyewall convection, like the spokes radiating out from the hub of a bicycle wheel.

Have a quick peek at: (time sensitive)

http://www.prh.noaa.gov/hnl/satellite/Hawaii_IR_loop.gif ... and ...

http://www.prh.noaa.gov/hnl/satellite/State_VIS_loop.gif

... and you will certainly see thousands of fine filaments if cirrus ice crystals streaming directly away from the inner core convection in all directions, although more so in the direction of the shear. I believe this is called 'Transverse Striate Banding' and discussed it in a post earlier this season.

My understanding is that this phenomena is evidence of a 'well-ventilated' cyclone and is often associated with the beginnings of a deepening cycle, as a TS into a hurricane or a min cat hurricane into a much stronger hurricane.

The point I am trying to make here is that these most recent animated satellite signatures do *not* look like a hurricane that is being quashed and ripped apart all too quickly, as we've all seen so many times over the years, but rather a cyclone that is at least holding it's own for the time being, or even attempting a strengthening phase.

My layman's interpretation is that the shear is lessening a tad to provide this satellite signature, or Flossie is persisting to maintain itself despite whatever shear there currently is. At any rate, Flossie is still a quite respectable hurricane.

Back to the eyewall dynamics: I've been watching Flossies' eyewall since first showed upon long range NEXRAD (now visible on short range, as well) and can say that, despite the 'visible' eyewall collapse on IR loops overnight, the eyewall has increased in convection considerably, and is verified with recent IR and visible loops, too. (See again the above links for visual eyewall transformations.)

Here's a link for the short range NEXRAD loop, so you can follow along as Flossie passes just south of the Big Island.

http://radar.weather.gov/radar.php?rid=HWA&product=N0R&overlay=01100111&loop=yes

So, although Flossie has thankfully been sheared to some extend, she remains a viable and potentially dangerous storm, should she encroach closer to any islands.

It should be noted that in the latest (11am HST) advisory/discussion package, mention of the fact that, after 24 hours, models diverge considerably, and a closer approach to, yet parallel to the islands still cannot be ruled out.

And whatever shear there is would push a stronger storm on a more northerly track. So we'll still have to watch Flossie very closely for another day or two. Hurricanes passing south of the Islands can be treacherous and sometimes difficult to accurately predict with regard to intensity and track, especially of the upper level dynamics to not pan out exactly as forecast, etc.

Tropical Storm Warnings are up and the prudent Hurricane Watch, as well, and the topography of the Big Island volcanic slopes will certainly have an effect, possibly resulting in near-hurricane or hurricane force gusts in certain prone locations, and the surf is pounding in and will surely cause run up and property damage in exposed locations.

Keep one eye on Dean and the Invest in the GOM, but keep the other on the Eye of Flossie as she slows down and lumbers past the Big Island today and tonight.

Thanks to all that have contributed to the post. Keep it up!

More later when I can find the time ...