22 April 2003

Ana now a tropical storm...

Against all odds and certainly against climatology, Subtropical Storm
Ana has been upgraded to Tropical Storm Ana at 15Z today.  She has
transitioned from a hybrid cold-core system to a fully warm-core one, as
shown by satellite soundings and imagery, and buoy obervations.  There
is evidence of a warm core aloft and near the surface, and as such, the
strongest winds have migrated inward near the core.

At 15Z, Ana was located at 29.9N 57.5W and tracking E at 14kts.  Winds
have reached 45kts and the central pressure has fallen to 996mb.  This
intensification and tropical transition is truly remarkable considering
the environment there (21C SST and 30kts of westerly shear).  The
forecast is for a continued eastward trek, and intenisty to remain
roughly constant, possibly weakening in the high shear.  This is a
balance of model forecasts, which range from maintaining Ana at current
intensity, to dissipating her in the high shear.

Please visit my tropical Atlantic headquarters.

21 April 2003

Ana forms near Bermuda...

You're probably saying to yourself, "it's not even June 1st yet, why am
I getting tropical updates already?!".  Well, a record has been set
today in the Atlantic.  Subtropical Storm Ana formed near Bermuda at 03Z
today, the earliest ever in the Atlantic basin (second place is STS-1 on
April 21st at 12Z, 9 hours later than Ana).  By the way, subtropical
storms were only given names since 2002, otherwise Ana would be STS-1.

At 03Z on Monday (11pm EST on Sunday), a Low that was west-southwest of
Bermuda developed sustained deep convection near its core, warranting
classifying it as Subtropical Storm Ana.  Tropical Storm Warnings for
Bermuda have issued and cancelled as the system fluctuates in
organization.  As of 15Z today, Ana was located at 29.8N 64.2W and
tracking ESE at 10kts.  The maximum sustained winds are 35kts with a
minumum central pressure of 1002mb.  Conditions would not appear
favorable for even this level of development: sea surface temperature
under Ana is 20C and she's in 25kts of vertical wind shear.  The
forecast is for gradual dissipation as she's carried eastward ahead of a

This will most likely my only update on Ana, as she's weak and not
threatening anything.  I suspect it will be another couple months until
I will be writing another update.

Please visit my tropical Atlantic headquarters.