deteriorated a bit before pulling himself together this morning) and now
has winds of 45mph (TS: 39-73mph) and a central pressure of 1002 mb, but
he did pick up his pace and is moving westward at 8mph now. His center
is somewhere around 28.2N, 90.6W and he's expected to turn WNW today
with landfall still somewhere around Galveston, TX tomorrow. Landfall
will be within the cone, but it's not clear exactly where which is why
everyone in that area should be prepared.
The circulation has improved since yesterday, and he looks like he's
desperately trying to form areas of deep convection. They tell me that
there is vertical wind shear that is keeping his intensity down, and
there is a bit but it's about 5 -10 knots (5.75-11.5 mph) at the most,
and if you look at satellite images of him there clouds have formed on
all sides of the circulation so I'm not as convinced that's the reason.
But, for this storm, I will go with the NHC information because planes
have been in this system since yesterday and have really good
observations on this storm (which is where they got the data to realize
he was a TS in the first place). He is heading towards a region of
slightly higher shear, but still remains over water temperatures greater
than 29 deg C.
Currently, water levels along the coast are at the most 1 foot above
normal (in areas around the mouth of the Mississippi River). You can
look for yourselves on www.tidesonline.com. The directions are in one of
my previous entries (July 22):
http://jyotikastorms.blogspot.com/2008/07/ts-cristobal-and-hurricane-dolly-july.html.
The blue line is the predicted normal water level, the red are the
actual observations, and the green line on the plots gives you the
difference between the expected value and the observations - so the
'above normal' water level. Because a storm is a low pressure system,
in the northern hemisphere the winds move around it in a
counter-clockwise direction. So water levels on the north/eastern side
of the storm will be above normal because the winds are pushing water
towards the shore, but water levels on the western side will be below
normal. You can see this at the moment. If you click on stations around
the Mississippi (e.g. Bay Waveland Yacht Club, MS) you'll see they have
higher than normal values. But if you click on stations in Texas (e.g.
Galveston Bay), you'll see that the water level was below predicted, but
is now beginning to rise as the storm moves closer to the TX coast.
If you tune in next time, I'm going to begin a two-part overview on
satellite images and where you can see them and what they mean. Towards
the end of Dolly, I saw one of my wonderful readers trying to see what I
was writing about...but in the wrong satellite images. Oops. This
morning I got another email from someone regarding satellite images, so
clearly it's time to shed some light on them. I guess the last time I
wrote about satellite images was a few years ago. Double oops. I'm such
a slacker...you guys should have sacked me ages ago! ;)
More later today...
J.
Blogs archived at: http://www.jyotikastorms.blogspot.com/
-------------------------------
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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