Tropical Depression Four was a very small tropical cyclone with limited
convection that approached the east coast of Florida. The precursor
disturbance was a low that disengaged from a frontal zone in the central
subtropical Atlantic on 4 August, and then moved southwestward over the next
few days. An Air Force Reserve Command reconnaissance aircraft found a
well-defined low level circulation with minimal convection on 8 August. The
system then moved westward with no increase in strength for two days. On the
10th, the depression was about 70 nautical miles east of Cape
Canaveral when it abruptly turned northeastward in advance of a deep-layer
trough over the eastern United States. The depression dissipated the
following day. The best track chart of the depression's path is given in
Figure 1, and the complete best track is given in
Table 1.
A reconnaissance wind report at 1500 ft of 47 kt could be used to argue that
the depression attained tropical storm status. However, the
(surface-adjusted) tropical storm force winds were reported during only one
pass through the system and covered an area less than 10 nautical miles
across. These winds are judged to have been unrepresentative of the system's
maximum sustained wind and so the cyclone has not been designated as a
tropical storm.
Table 1.
Preliminary Best Track - Tropical Depression Four, 8-11 August 2000.
Date/Time (UTC) |
Position |
Pressure (mb) |
Wind Speed (kt) |
Stage |
Lat. (°N) |
Lon. (°W) |
08 / 1200 | 28.2 | 74.2 | 1011 | 30 | tropical depression |
08 / 1800 | 28.1 | 75.1 | 1010 | 30 | " |
09 / 0000 | 28.0 | 76.0 | 1010 | 30 | " |
09 / 0600 | 27.9 | 76.8 | 1010 | 30 | " |
09 / 1200 | 27.9 | 77.4 | 1010 | 30 | " |
09 / 1800 | 27.9 | 77.9 | 1010 | 30 | " |
10 / 0000 | 28.0 | 78.6 | 1009 | 30 | " |
10 / 0600 | 28.3 | 79.3 | 1010 | 30 | " |
10 / 1200 | 28.7 | 78.9 | 1010 | 30 | " |
10 / 1800 | 28.9 | 78.3 | 1011 | 25 | " |
11 / 0000 | 29.2 | 77.8 | 1011 | 25 | " |
11 / 0600 | 29.4 | 77.2 | 1012 | 25 | " |
11 / 1200 | 29.6 | 76.5 | 1013 | 25 | " |
|
10 / 0000 | 28.0 | 78.6 | 1009 | 30 | minimum pressure |
Figure 1.
Best track positions for Tropical Depression Four, 8-11 August 2000.