TD2 slowly organizing...

A combination of low-level stable air and moderate easterly wind shear is keeping TD2 below Tropical Storm intensity.  The latest intensity estimate is 30kts and 1006mb, and still heading W at 11kts.  The forecast track has changed very little since yesterday.  TD2 is still expected to reach TS status later today.

Elsewhere, the potent easterly wave I referenced yesterday has now exited the African coast and will be monitored for development.  Several computer models suggest this could become a storm to cause concern in the distant future.

I wanted to point out that my webpage at http://einstein.atmos.colostate.edu/~mcnoldy/tropics/atlantic/ is a little different... I reorganized the links.  So you might need to hunt around a bit at first to find your favorite resources, but hopefully the new system will work out better for people.

Please visit my tropical Atlantic headquarters.

Second Tropical Depression of the season forms in far eastern Atlantic...

Two and a half months after TD1 formed off the northeast US coast, TD2 forms near the Cape Verde Islands off the west coast of Africa.  This is peculiar in two ways: it's rather late in the season to have the second Depression form, and it's rather early to have the "Cape Verde season" kick in.  The easterly wave that became TD2 was over Chad on August 4, and exited the African coast on August 8, so it has been a feature of interest for some time.  There's actually another potent easterly wave now located over Guinea, but that'll be a topic for a future discussion.

At 15Z today, TD2's intensity was estimated at 25kts and 1006mb.  It is located at 14.6N 29.6W and tracking W at 11kts.  It is embedded in an area of dry air (negative factor), it is over 27C water (neutral factor), and is in an area of minimal vertical shear (positive factor).  By this weekend, it may begin to feel a weakness in the subtropical ridge begin to move a bit more NW, potentially avoiding the Lesser Antilles.

It is forecast to become Tropical Storm Ana within a day, but maintain weak TS status for the near future.
The last time the second Depression formed this late in the season was 2000 (August 13, became TS Beryl).  The last time the first named storm formed this late in the season was 1992 (August 17, became Hurricane Andrew).

Please visit my tropical Atlantic headquarters.

Easterly wave making its way across Atlantic...

On August 1, a potent African easterly wave exited the coast and is now centered near 35W.  There is evidence of a mid-level circulation in the satellite imagery, and a hint of a weak surface circulation based on microwave scatterometer and visible satellite data.  It has also maintain a small cold cloud shield over the center of the mid-level circulation.  This system, though poorly organized now, could become better organized in the coming days.  It would reach the Lesser Antilles this weekend if it holds together.

Elsewhere, the basin is quiet.  However, this is not atypical... climatologically, there is only one tropical storm by this date, and no hurricanes.  The first name on this year's list is Ana.

Please visit my tropical Atlantic headquarters.