Subtropical depression Andrea: May 10

Subtropical depression Andrea is not doing so well, and I'd agree with
all the official advisories.

She is embedded in an area of high pressure, which always makes the
forecasting a bit more difficult, and explains why she is just drifting
along. When a low pressure system encounters high pressure, it's like a
ball trying to roll up-hill - not easy to do. She is still surrounded
by dry air on almost all sides, she is now in a region of higher wind
shear from the west-northwest, the water temperatures are still too
cool, and she is interacting with land on the western side. So not much
to keep her growing.

Although she is a weak storm the forecast for the next few days is
complicated. Unless she dissipates, which is very possible given the bad
atmospheric environment and the proximity to land, her southward drift
takes her over warmer waters. To complicate this some more, there is a
low front that was over Nevada/Colorado yesterday, and has reached Texas
today and is moving in this direction. So, if Andrea stays intact the
models are predicting that this front would move the storm eastward in a
few days, and I can see that as a possibility as well. It all depends on
how well she hangs together in the next couple of days.

That's all for now on this storm unless something 'interesting' happens.
Hopefully you won't hear from me again for a couple of months - wouldn't
that be nice? :)
-------------------------------
DISCLAIMER:
These remarks are just what I think/see regarding tropical storms (my
storm blog). If you are making an evacuation decision, please heed your
local emergency management and the National Hurricane Center's official
forecast. This is not an official forecast.
-------------------------------------------

J.

Subtropical Storm Andrea: May 9, Update B

It's officially the first named storm of the year.

Andrea is still moving slowly westward, but a high pressure to the west
suggests that she will make landfall probably somewhere along northeast
Florida. She is not a big storm with winds around 45 mph (TS winds:
39-73 mph). The system is moving very slowly (3mph) so there is time
for a bit of intensification as it continues to interact with the Gulf
Stream, but not enough to make a hurricane because it is already
interacting with land.
J.
-------------------------------
DISCLAIMER:
These remarks are just what I think/see regarding tropical storms (my
storm blog). If you are making an evacuation decision, please heed your
local emergency management and the National Hurricane Center's official
forecast. This is not an official forecast.
-------------------------------------------

Subtropical storm: May 9, Update A

Good morning,

Our potential first named storm of the season is still loitering
mischievously off the S. Carolina/Georgia/Florida coast. All you
surfers... time to pop over to the east coast of Florida.

The NHC sent a reconnaissance plane in to investigate this morning. I
suspect they will give this one a name later today. It has wind speeds
in the lower end of the Tropical Storm range (34-63kt, 39-73mph), it has
a broad, not well-formed eye, and a pretty good circulation. In the
atmosphere, the wind shear is low, which is favorable for the storm.
However, it is almost completely surrounded by dry air, which is not so
favorable. In the ocean, it is hanging out over water temperatures of
about 24-25 degs C, which is lower than those needed for storm formation
(generally 26.5 deg C and above are the temperatures to keep an eye out
for - all puns always intended :) ). It has begun to interact with land,
which will also keep it from developing.

So... the question is that given all the conditions that would prevent a
storm from developing, why has this persisted? One reason is that it is
very slow moving and has basically remained over the Gulf Stream for
most of it's life. Although the surface waters of the Gulf Stream are
warmer than surrounding waters, the important factor is that the water
is warm here with depth as well, so the water that is being churned up
from beneath the surface of the ocean is as warm as the surface, not
colder as you might expect. The persistence (and weak strength) of this
storm has very little to do with actual surface temperatures and global
warming, and in that respect it is like many storms we have seen over
the past few years, and will probably see again this year. Another
reason is that it was formed as part of a frontal system in the
atmosphere, so it had a lot of energy (and water vapor) associated with
it to begin with as it developed into a non-tropical low pressure system.

I'll send out another note once I hear they have named it (or not).
Toodles,
J.

Subtropical Storm

Hello everyone... I'm back from hibernation. I know I know, 'Hurricane
Season' doesn't officially start for another few weeks, but mother
nature never listens to us. There is a reason for this email - see
below. For those of you who have joined this list over the past few
months, welcome. If at any point you want to be removed, just send me an
email. For those who have been with me for the last 3 years, welcome
back :) As usual, if you have any questions, please drop me a line.

-------------------------------
As the first email of the upcoming 'exciting'?!? hurricane season 2007,
I'm going to put my disclaimer up front:

DISCLAIMER:
These remarks are just what I think/see regarding tropical storms (my
storm blog). If you are making an evacuation decision, please heed your
local emergency management and the National Hurricane Center's official
forecast. This is not an official forecast.
-------------------------------------------
And we're off:

Some of you have seen what appears to be a tropical storm off the
Florida/Georgia/Carolina coast (thanks to those who sent me an email
asking about it). There is, indeed, a low pressure system that has the
characteristics of a subtropical storm off the Carolina coast. The low
pressure is associated with a dying cold front (also connected to the
tornadoes in Kansas late last week). It is not unheard of that a
subtropical storm can develop into a tropical storm (TS), for example,
TS Ana in April 2003. Also, since 2002, subtropical storms have been
given names from the hurricane name list.

The atmospheric conditions look good for storm development - good
circulation and low wind shear at the moment. Winds in the storm are
Gale Force, which is 34-40 knots, or 39-46 miles per hour (mph).
Tropical Storm winds are 34-63 knots, so it's on the lower end of the
scale. It is pulling in dry air from the west and south, and the ocean
conditions are not too favorable at the moment. As your local weather
stations are probably reporting, it does mean some bad weather for the
Carolina's, Georgia and possibly Florida in a day or so. The movement of
the system is to the west. At the moment, this hasn't been officially
classified as the first Tropical Storm of the season, but I will send
out an email if the National Hurricane Center (NHC) decide to change
that status. As I was writing this, the NHC has issued a special
tropical disturbance statement, so everyone is watching this system. I'm
sure we will all hear a lot more about this in the news.

More later,
J.

testing for 2007

Ramping up for a new season - here's a test post.