a. Synoptic History
Kevin may have originated from a tropical wave
which moved from Africa to the eastern tropical Atlantic Ocean on 16 August. The wave
remained weak as it moved across the Atlantic at low latitudes and then across northern
South America. On the 26th of August, convection flared up just south of Panama in
association with the wave. The convection developed and dissipated intermittently
for the next several days as the system moved near and parallel to the Pacific coast
of southern Mexico.
Although satellite Dvorak classifications
began on 1 September, it was not until the 3rd that satellite imagery indicated a
well-defined low-level circulation, along with a small circular area
of deep convection near the center and a band of convection to the east.
Tropical depression status begins at 1800 UTC
on the 3rd while the system was centered about 325 nautical miles south-southwest
of the southern tip of Baja California. Fig. 1 (14K GIF)
shows a plot of the best track of
Kevin and this track is tabulated in Table 1.
The area of deep convection over the center
became larger and outflow aloft became better defined. It is estimated that Kevin
reached tropical storm strength
at 0600 UTC on the 4th and a maximum intensity of 50 knots
at 0000 UTC on the 5th. Only 18 hour later, at 1800 UTC, the center of the storm was
devoid of deep convection, which is an indication of significant weakening.
By 0600 UTC on the 6th, Kevin weakened to a depression and was reduced to a
swirl of low clouds 24 hours later. Kevin's motion was basically toward the west-northwest at
about 12 knots from the time it became a depression, as it was steered by a ridge to its north.
Late on the 5th, when it began to weaken and became de-coupled from upper-layer flow, it
moved more westward until dissipation on the 7th.
b. Meteorological Statistics
Figures 2 (11K GIF) and
3 (12K GIF) show curves of minimum sea-level pressure
and maximum one-minute surface wind speed, respectively, as a function
of time. Satellite data plotted in these figures are based on the
Dvorak satellite intensity estimating technique as applied at the
Tropical Analysis and Forecast Branch (TAFB), the
Synoptic Analysis Branch
(SAB) and the U.S.
Air Force Global Weather
Center (AFGWC). The ship Kentucky Highway reported
39 knots sustained wind at 1800 UTC on the 4th
while located about 110 nautical miles east-northeast of the storm center.
c. Casualty and Damage Statistics
Kevin did not affect land and there were no known casualties
or damage.
d. Forecast and Warning Critique
Average official track forecast errors were 15, 35, 30, and
43 nautical miles, respectively, for the 0-, 12-, 24-, and 36-hour forecast periods.
Kevin was a tropical storm for only two days and only eight forecasts were verified.
No 48- or 72-hour forecasts were verified.
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