A tropical storm warning is still in effect for the Cape Verde Islands.
At 5 a.m. EDT, the center of Tropical Depression Four was at 12.8 north, 24.6 west, which is 140 miles south of the Cape Verde Islands. The depression is moving west-northwest at about 16 mph. Maximum winds are estimated to be 35 mph with gusts to 45 mph, and the minimum central pressure is estimated to be 1007 millibars, or 29.74 inches of mercury.
This morning, T.D. 4 will bring squalls of heavy rain to the southern Cape Verde Islands. Several inches of rainfall will fall from this system, especially in the higher terrain of Fogo Island, where over 5 inches of rainfall can occur. Winds will continue to be gusty, mainly within the heavy squalls of rain.
Conditions in the eastern Atlantic are favorable for this depression to strengthen slowly. There is little wind shear and the clouds of dust coming off the Sahara have diminished over the last few days. The waters in this area are warm enough to support a tropical storm, but not by much; sea-surface temperatures are close to 80 degrees and this warmth cannot be found to substantial depth. The depression should reach tropical storm status sometime Tuesday, and the next name on the list for the Atlantic Basin is Debby.
Steering currents will take the depression to the west-northwest for the next few days, and the waters are not much warmer in its path during this time, so it is reasonable to expect only slow strengthening. However, when this feature reaches 40 west, which should occur Thursday night or Friday, the waters become warmer and the warmth is much deeper. So, it could strengthen considerably at that time. At this point, it appears that an upper-level trough of low pressure will begin to steer what should be a tropical storm by then on a more northwesterly path by this time, taking it into the middle of the Atlantic. However, should the storm end up farther south than forecast, then the storm can slip south of the trough and a more westerly path toward the Lesser Antilles is possible.
There is a tropical wave in the central Caribbean near 75 west, south of 19 north, moving west at about 15 knots, but there is very little shower and thunderstorm activity with this wave and it will not develop further anytime soon. Another tropical wave is close to 58 west, south of 19 north and is causing spotty thunderstorms as it tracks westward at 15 knots. However, there is no sign of organization along this wave and strong southwesterly winds causing shear will prevent this feature from developing further, as will a cloud of Saharan dust that is along and west of the wave. The same clouds of Saharan dust is choking the last feature to watch, a tropical wave that is present along 45 west, south of 19 north. It is causing just a few thunderstorms as it tracks to the west at about 15 knots.
A large batch of showers and thunderstorms are also affecting Central America. This is due to a tropical wave crossing the region. Since the wave is now primarily over land, tropical development is not expected in this area.
