Isabel a very strong CAT4 hurricane...

Since this time yesterday, Isabel's MSLP has fallen and additional 18mb
and sustained winds have increased by 15kts.  After a brief period of
shear and internal reorganization, she has now taken on the most classic
of appearances, rivaling anything else in recent memory.  The outflow
channels are well-established, the eye is clear and hard-edged, and the
eyewall forms a thick symmetric band of -75C cloud tops.  As of 15Z
today, Hurricane Isabel was located at 21.4N 54.5W and tracking W at
8kts.  Intensity is 130kts and 930mb.  The CAT5 transition occurs at
140kts and about 920mb, so she's just borderline, and with SSTs of 28.3C
and increasing, it's not out of the realm of possibility over the next
couple days to see the basin's first CAT5 hurricane since Mitch '98.

Phil Klotzbach (CSU) reports the following: "As of the 15Z advisory
today, we have already had 8.75 IHD this month which puts us in a tie
for sixth place all-time with 1995.  The maximum number of IHD for
September is 15.75 set in 1961.  Isabel alone could very likely put us
at or very close to that record."

NHC's 5-day track forecast places her just northeast of the Bahamas by
Tuesday morning, and if she recurves into the US east coast, it would be
about 7-8 days from today... just something to keep a close eye on as
the days go by.

If you wish to be astounded with high resolution (1km spatial and 1min
temporal) visible satellite imagery from GOES-12, please visit
http://www.cira.colostate.edu/ramm/rmsdsol/RSOMAIN.HTML and click on the
GOES-EAST Visible Floater link.

Please visit my tropical Atlantic headquarters.