Greetings all. Interesting turn of events.

Just as the northeasterly shear seemed like it was about to quash Boris, the diurnal convective maximum arrived, local basin time, and like the night before, Boris put out a pretty impressive convective burst.

Again, a large mesoscale convective complex, with extremely cold cloud tops of -80 and colder flared to the S and SE of the partially exposed LLC, and gradually these intense thunderstorms 'trained' towards the center, forming a large, kidney-bean shaped 'blob'. (See figure 1, below)

Just as one such event faded over several hours, another, even larger convective blast took it's place, even closer to a now less-exposed circulation center. And parallel bands of intense convection were stacked due south of the center, extending for hundreds of miles. (See figure 2)

Meanwhile, I was checking out some of the interesting microwave imagery from the superb NRL website, and noticed something interesting.

While looking at the 0920Z Tropical Rainfall Measuring Mission (TRMM) satellite image, I noticed that the surface LLC (shallow cumulus and stratocumulus, shown as light blue on a brownish-green background) was slightly decoupled from a narrow 'convective ring' that was attempting to establish itself as the new intense convection trained and wrapped itself around center (narrow band of thunderstorms, shown as the bright red ring of precipitation). The offset seemed to be as much as 20 or 30 miles to the SSW. (See figure 3)

This is what is sometimes referred to as a de-coupling; when the mid-level and the low-level circulations are no longer vertically aligned. Taken to extremes, the thunderstorms become totally sheared off in one direction, while the LLC continues to chug along, becoming utterly devoid of any deep convection; a swirling pinwheel of only light showers. We've all seen this happen many times, a fairly common occurrence, and how many a cyclone has met it's early demise.

But! And here's where it gets interesting: Sometimes the shear will slacken a tad and/or the convection will, for whatever reason, tend to 'buck' the shear, and overtake and overspread what was an exposed LLC and re-establish a nice, vertically aligned column of deep convection, and wallah, the cyclone is granted a 2nd lease on life.

Well, such seems to be the case with Boris this morning. After putting on a very impressive convective burst all night, that activity is overspreading the LLC again, which seems to have re-invigorated Boris.

And a more recent, more complete, microwave pass continues to suggest Boris attempting to re-align itself in the vertical. (See figure 4) The time between the 2 microwave passes is only 22 minutes, so the convective 'ring' still appears to be displaced about 20-30 miles to the SSW of the apparent LLC.

Figure 1 - First large flareup of deep convection, forming 'kidney bean' shaped area.

Figure 2 - Second such flareup, about 6 hours later, after first one dissipated. NOTE also the small, circular 'eyewall-like' formation to the NW of the bigger convective mass. This is the pseudo-eyewall that clearly shows up in the passive microwave images in Figures 3 and 4 as the bright convective ring.

Figure 3 - The first microwave pass from the TRMM satellite, showing the bright red convective ring, located about 30 miles SSW of the LLC. Note that these two 'rings' are not that far apart; they actually overlap one another. See description accompanying next photo.

Figure 4 - The 2nd such pass from the AQUA-1 satellite, 22 minutes later, shows the 'loosely-coupled' cyclone better. If you look close, you can see the southernmost part of the LLC (light blue) through the middle of the red convective ring, *and* you can see the northern, weakest portion of the convective ring directly overlying the middle of the LLC. Essentially overlapping rings.

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As of this writing, no new microwave images have come in, so I can't be entirely sure, but just from looking and judging the IR loops, it sure seems to my untrained eye that the deep convection is not only persisting, but is completely overspreading the LLC. This intense activity is now developing a CDO, or central dense overcast, usually an indicator of a deepening cyclone and a strengthening wind field.

The last few frames have shown a slight warming of the cloud tops, but this may be a reflection of the end of the diurnal convective maximum mentioned earlier, with the approach of the coming dawn, local basin time.

The storm is currently hugging the 27 C isotherm and the more stable air mass to it's N ans NW is not being ingested quite yet. So, beside the shear factor, it seems it's up to Boris if he can re-couple and re-align his mid and low level circulations, and live another day as a respectable tropical storm, and even maybe strengthen just a tad more. Next advisory out in about an hour from now.

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UPDATE: Latest advisory now out. NHC is maintaining Boris at 45 Kts, but I still feel there's a small window of opportunity to strengthen some, especially since the shear appears to be letting up a little and outflow is improving in all quads. Even though the T numbers may not support it, I'll bet the Boris is currently stronger than indicated.

With this kind of sustained convective activity near the center and considering the improving outflow, how could it not strengthen? It all seems to depend on the whether Boris can successfully re-align it's circulation centers, before (a) the stable environment takes its toll, (b) the shear collapses the now partially aligned center, or (c) the system slows to a crawl and is eventually ingested by the much larger cyclonic circulation forming to its east.

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This should be interesting to see how it plays out. The GFDL and HWFR models do strengthen Boris in the near-term, but admittedly, they are the 'outliers'.

Will the coming convective minimum and the NE-erly shear conspire together to send Boris to his demise, or will he maintain his tenacity in the face of adversity?

I'm putting my bets that Boris will put on one last hurrah and surprise the nay-sayers. Any takers ??