Erika forms in the central Gulf...

At 21Z on Thursday, the disturbance I had mentioned off the coast of
Florida developed into Tropical Storm Erika, the fifth named storm of
the season.  It organized quickly upon entering the Gulf, and continues
to do so, threatening areas along the western Gulf coast.

As of 15Z today, TS Erika was located at 26.1N 91.4W and tracking W at
20kts.  This forward speed is racing it toward the coast, and the
question that remains is how fast will she intensify before making
landfall.  Current intensity is 45kts and 1008mb (surprisingly high
pressure considering the appearance).  The satellite presentation is
beautiful, with a cold CDO, obvious banding features, and symmetric
outflow aloft.  Cloud tops at the center are nearly -80C, with a large
dome of -70C or colder.  SSTs under the forecast track are in the 29-30C
range, supplying enormous amounts of energy to the storm.  And although
that warm water doesn't extend very deep, Erika is moving fast enough
that upwelling will not be a concern. (I'm a bit lost for words as to
why she hasn't developed faster... conditions seem optimal, yet she's
still a TS)

A Tropical Storm Warning is in effect for parts of the Texas coast
between Baffin Bay and Port O'Connor.  A Hurricane Warning is in effect
from Baffin Bay, TX southward to La Pesca, Mexico.

The forecast is for continued strengthening, and a westward track,
making landfall near Brownsville as a hurricane during the early morning
hours on Saturday.  With nearly 24 hours remaining until landfall from
the time of this writing, a lot can happen with a storm, and coastal
residents need to be prepared for the possibility of a rapid
intensification (NHC is typically and appropriately conservative with
their forecasts).

Elsewhere, a tropical wave that exited the African coast yesterday is
now at about 13N 25W (very near the Cape Verde Islands) and moving W at
10kts.  There is an embedded 1010mb Low with this wave, and conditions
in advance of it appear favorable for gradual development during the
weekend.  The next number/name on deck are TD9/Fabian.

I want to direct you
specifically to a great visible shot from 1445Z today, available at
http://www.nrlmry.navy.mil/archdat/atlantic/tropics/vis/20030815.1445.goes12.vis.x.trop.x.jpg. 
You can clearly see Erika in the central Gulf, and the disturbance over
the Cape Verde Islands.

Please visit my tropical Atlantic headquarters.

Development in the Gulf...

A feature I've been watching for several days (seemingly spawned by an
upper-level Low closer to Bermuda), approached the U.S. mainland
yesterday and just crossed the central Florida peninsula.  It has
gradually been getting better organized and deep convection has been
persistent.  It's now near 27N 83W, MSLP of 1013mb, and showing signs of
banding as it enters the Gulf of Mexico west of Fort Meyers, FL.

Aircraft recon into the system was unable to locate a closed surface
circulation, but the mid-level circulation is very well defined as
evident on satellite imagery.  You can also see the mid-level
circulation on Tampa's NEXRAD radar
(http://www.srh.noaa.gov/radar/latest/DS.p20-r/si.ktbw.shtml).

It seems likely that this will develop into TD8 sometime today, and
perhaps a named storm within 24 hours (Erika is the next name). Some
model stuff: ETA and GFS are hesitant to intensify the system very much,
but they both track it due west into northern Mexico (Tampico-ish) on
Saturday morning.  NOGAPS keeps the same timing, but a bit further
north, around Brownsville.

Please visit my tropical Atlantic headquarters.

Disturbance slow to get going...

Same system I've been talking about for the past couple days, but it's
in moderate easterly shear, and more importantly [it seems] is that it's
in a stable, dry air mass.  This has choked off convection and inhibited
new convection from firing.  However the circulation is still intact and
awaiting more favorable conditions, which should be just a day away.

Presently at about 11N 42W and tracking W at 15kts, the MSLP is stil
1010mb.  The computer models paint a grim future for this system... very
hard to find a solution that intensifies the storm.

Please visit my tropical Atlantic headquarters.