Wednesday, September 02, 2009

TS Erika: September 2 Update A

She's not a very strong storm and she's a bit discombobulated which makes
it a little tricky seeing exactly where her center of circulation is. The
NHC had it at 16.2 N, 61.1 W at 2pm. I think it might be a bit west of
that, possibly already in the Caribbean. Her convection, which has
remained east of the center of circulation, decreased over the past few
hours. My theory is that it decreased as her center interacted with the
leeward islands. She's moving west at 10mph. I think her convection will
continue to decrease as she continues to cross those islands. I know they
only look like blips on a map, but we've seen them take the steam out of
storms in the past (all puns intended :) ).

Currently they have her winds at 40 mph, making her barely a TS (range:
39-73 mph). Central pressure estimated to be 1008 mb. A plane is heading
into the system to assess conditions. I don't have good pressure fields,
so I can't comment too much on the track. But from what I've seen, I'd
agree that she'll resume her WNW motion, essentially catching as many
islands as she can before getting to the Bahamas, including the VIs. She
may not be much by the time she gets that far though.

The other factor that's playing a role is the wind shear, which as I
expected, has increased. I am not sure what data the NHC are looking at,
because they said wind shear increased sooner than expected??!? I thought
we were looking at the same thing. Hmmm. Well I'm sure the plane will get
us all caught up. With disorganized storms like this, the forecast is
tricky, partly because it's difficult to find the center.

If anything unusual is found, I'll send out another update. Otherwise
tomorrow it is. I know that folks were scrambling to get boarded up
earlier today on the islands, partly because of the belated notice and
partly because the track shifted closer towards them than expected. Let
me know how things are out there if you can.

Toodle pip!

These remarks are just what I think, and I could be totally off my rocker.
So if a storm is approaching, please heed your emergency managers, the
NHC, the weather service as they have more up to date information. If I
was hypothetically there, I'd let you know if I was going to 'run away,
run away' (Monty Python) or stay put and have a glass of wine instead.

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