As a number of you noted, the center of Dolly was shifted northwards
this morning and now I feel much better about this system. :) I now
agree with the NHC that she is truly a tropical storm and is shaping up
very nicely (in a scientific sense). My concern with the center not
being correctly located yesterday is playing out today - with the more
northern location, she barely clipped the Yucatan Peninsula so she is a
lot stronger this morning than she would have been if she had followed
the track they had yesterday which would have taken her over land for a
longer period of time. This now sets her up to become a stronger storm.
There are hurricane and tropical storm watches along the Texas and
Mexico coastlines and the NHC expect her to become a cat 1 storm
tomorrow, with landfall on Weds. I would not be surprised if she becomes
a hurricane by the end of today given her little interaction with land,
warm waters and low wind shear environment.
Currently, she is at 22.1N, 89.5W and has winds of 50 mph, central
pressure of 1005mb (TS wind range: 39-73 mph). A plane went into the
system this morning and confirmed closed circulation, which is obvious
in any satellite image of her now. She is moving a little more westward
than yesterday, which is also something I was expecting given the
surrounding pressure fields. Her motion is W-NW at 18 mph. The exact
landfall location is still unknown, so keep an eye on the entire cone
not just the center.
From this point out, sea surface temperatures in her track are between
28-31 deg C - very warm. The warmer 26 deg C temperatures extend down to
about 75 m depth across most of the southern Gulf, but at the moment she
is also interacting with the very shallow and broad Campeche Banks just
north and west of the Yucutan Peninsula where warm waters only extend
down to about 25m. I keep mentioning the warm water and how deep it is
because as a storm passes over the surface it churns up water from
beneath the surface. As you can imagine, it makes a difference if the
water being churned up is cold or warm. I disagree with the NHC in
their assessment of the reservoir of warm water underneath:
"IN ABOUT 18-24 HOURS...DOLLY IS EXPECTED TO PASS OVER SSTS GREATER THAN
29 CELSIUS...AND A RELATIVE MAXIMUM IN OCEAN HEAT CONTENT...AN AREA WITH
A SOMEWHAT DEEPER RESERVOIR OF WARM WATER BENEATH THE SURFACE."
She passed over the relative maximum reservoir in upper ocean warm water
in the northern/eastern Caribbean - around Jamaica and slightly west, as
I mentioned in a much earlier entry. I'm not sure what information they
are basing this statement on.
Dolly is growing in areal extent and there is a lot of water vapor
around her - in fact she is impacting upper level winds over most of the
Gulf of Mexico. I will discuss her further this afternoon, after I get
the next set of pressure maps. For now though, I think she will continue
more westward than northward, and will continue to intensify.
TS Cristobal:
As with Dolly yesterday, I think the NHC have the center of circulation
in the wrong place. Although this storm does not have a good structure,
they have the center located at 36.6N, 72.6W. This is entirely north of
the area of convection. It almost looks to me as though the center is
about 1 degree south - at 35.6N, 72.6W. Maybe someone just entered the
wrong number? He is moving NE at 13mph, and is following a high pressure
system (remember, things move clockwise around a high pressure in the
northern hemisphere). Winds have picked up to 65 mph, making him a
strong Tropical Storm now. I think it was yesterday I said we could
expect some strengthening because he is moving away from land and is
still over warm waters of 27-28 deg C. At least an incorrect center in
this case will not affect anyone (unless you are out on a boat in the
Atlantic).
That's all for now - more later when I have the latest pressure
information in hand.
Toodles,
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.
-------------------------------------------
Posts
No comments:
Post a Comment