Monday, July 14, 2008

TS Bertha and The Blob: July 14 Update B

Hmmm... "TS Bertha and The Blob", now there's a movie just waiting to be
made. A romantic comedy perhaps.

Tropical-Storm-I'm-almost-a-Hurricane-again Bertha:
The warm surface waters around Bermuda that I mentioned this morning are
proving to be a stronger factor than the wind shear (which is still to
her north), so she intensified whilst passing over Bermuda and will most
likely become a Hurricane before the day is done (and before she's
finished hanging about Bermuda). Although her eye is north-east of the
island (33N, 64.1W), the southwest quadrant is where the really strong
convection is happening - right over both the island and water
temperatures of over 29 deg C.

I got a report from Bermuda at 11.30 this morning saying it was "just a
wet windy day"... and then one at about 3.30pm saying "now its a
storm!". The official NHC 5pm advisory still has her as a Tropical
Storm, but barely. Her maximum sustained winds are about 70 mph (TS
winds: 39-73mph) so she's a strong TS. She is heading northward at 9mph
and will begin to turn north-eastward tomorrow. I'm not sure about the
south-eastward turn that the computer models are predicting in a few
days time, but as I said earlier, it's academic at that point because
it's out in the Atlantic.

Let me tell you, those folks on Bermuda are a hardy bunch. I just got an
email as I was composing this, sent at 4.45pm: "It's teeming with
sideways rain. my umbrella was a victim. walking home was
interesting."... followed by "the happy little Bermudian tree frogs are
singing in the rain (and wind)."

So ummm... enjoy your research cruise scheduled to depart from Bermuda
at 7am tomorrow... (I have an inkling that it may be postponed another
couple of days -shh... don't let them know) ... have another cup of tea
folks, or maybe its time for something stronger to match the stronger
storm - which I expect is your preference too.

Everyone else, raise your hands if you are tired of Bertha and would
like to talk about something else? Ooh.. a number of you. Well this is
your lucky day...

The Blob:
The circulation in this blob (technical term meaning... a blob ;) -
something I call a region of unusual convection) that some of us have
been watching over the past few days has improved. The convective
activity decreased a bit this afternoon and cloud tops are warmer now,
but there is more rotation (or vorticity if you like). Interestingly,
the rotation is (at the moment) confined to a height of 2-3km in the
atmosphere - it's not at the surface and it's not any higher, so this
system is still very much in the developmental stages. The NHC have not
yet called it a Tropical Depression, but it is moving in a W-NW
direction at 15 mph.

The circulation appears to be centered somewhere around 12N, 43.5W,
along with the convection. The pressure fields are changing a little
bit, so this could pass into the Caribbean at any place (if it continues
to develop) - including the northern end. I just wanted you VI people to
be aware and keep an eye on it - as if you weren't already! It could
also still head towards Jamaica. At this point it really is too soon to
tell. It's over water temperatures of 27-28 deg C and in a low
wind-shear environment so something to watch.

I hope those of you in Bermuda stay safe. I look forward to hearing from
you after the storm passes.
Toodle pip for now,
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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