Sunday, October 12, 2008

TS Nana & The Blob: October 12 Update A

TS Nana:

Hey, guess what...there's another one of those little blobettes out there
in the Atlantic. Yes, one of those "shouldn't really be a named system but
we'll give it one anyway because we've still got about half the alphabet
claiming unemployment". :)

The NHC issued their first advisory on TS Nana at 5pm this afternoon and
they forecast that she'll be downgraded to a Tropical Depression later
tonight. Still, it gives them something to do for the next few hours I
suppose.

The center of circulation is clearly visible because there are only very
light clouds in the area. It is at around 16.5N, 38.5W with winds near
40mph (TS range: 39-73 mph) and a central pressure of about 1005mb. There
is some convection, but because of strong westerly (from the west) wind
shear the convection is east of the circulation, near 16.5N, 36W - that's
about 150 miles from the center of circulation! She's moving WNW at 7mph
and looks like she'll stay out in the Atlantic.

With the convection removed from the storm center, I don't think she
should have been named a TS. I think I mentioned this before - in addition
to vorticity (circulation) a tropical system should have convection close
to the center as well.

Water temperatures are warm enough (27-29 deg C) for her to develop, if
the wind shear decreases. But the forecast wind shear is supposed to
continue as it is for the next couple of days.


The Blob:
There's also a Blob in the Caribbean. Convection is pretty good with this
system, and although there is some circulation, it isn't very well defined
at the moment. It looks like PR/VIs etc might have got some rain today...
(and I hear there was an earthquake in that area as well yesterday?).
Water temps are 28-30 deg C. I'll write more on this if it develops
further.

By the way, the next few names are: Omar, Paloma and Rene. That should
cover us up to the 'pre-season forecast' number that someone is
desperately trying to get to I think.

More tomorrow.
Pip-pip... :)
J.

Blogs archived at: http://www.jyotikastorms.blogspot.com/
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DISCLAIMER: These remarks are just what I think/see regarding tropical
storms - not the opinion of any organization I represent. If you are
making an evacuation decision, please heed your local emergency management
and the National Hurricane Center's official forecast and the National
Weather Service announcements. This is not an official forecast. If I "run
away, run away" (Monty Python), I'll let you know.
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