a. Synoptic History
Gil formed from an area of disturbed weather which gradually
became organized in the Gulf of Tehuantepec. The disturbed weather
might have been associated with a
tropical wave, though it is
difficult to track this weather system back to the coast of Africa.
On 19 August, a low- to middle level circulation with deep
convection was moving slowly westward along the southern coast of
Mexico as indicated by satellite images. It is estimated that the
system became a tropical depression
at 1800 UTC 20 August, about 100 n mi to the southeast Acapulco. Based on a ship report,
the depression was upgraded to Tropical Storm
Gil at 1100 UTC 21 August. The ship observation corresponded to 0600 UTC but it was
received a few hours later. Therefore, it is indicated in the
that depression became Tropical Storm Gil at 0000 UTC
on the 21st. Gil moved toward the west away from the coast of
Mexico during the following couple of days. It then turned toward
the northwest and reached its estimated maximum intensity of 55
knots and minimum pressure of 993 mb at 1800 UTC 24 August.
Thereafter, the tropical cyclone
moved over cool waters and gradually weakened.
Gil's track is shown in Fig. 1 (24K GIF).
Table 1 is a listing, at six-hour intervals, of the best-track position,
estimated minimum central pressure and maximum 1-minute surface wind speed.
b. Meteorological Statistics
The best track pressure and wind curves as a function of time
shown in Figures 2 (21K GIF)
and 3 (19K GIF) are based on
satellite intensity estimates
from the National Hurricane Center (NHC), the
Satellite Analysis Branch (SAB) and the
Air Force Global Weather Central (AFGWC).
Ship ELCO5, located just to the northwest of the tropical cyclone,
reported 45 knots at 0600 UTC 21 August. This valuable
observation was the basis for operationally upgrading the depression to
tropical storm status. The observation was also very helpful in
adjusting the final best track.
c. Casualty and Damage Statistics
There were no reports of casualties or damage associated with Gil.
d. Forecast and Warning Critique
At the time of the ship report, the intensity based on
satellite data was underestimated. T-numbers on the Dvorak scale
were 2.5 and 1.5 from the NHC and the SAB respectively, suggesting
winds of 25 to 35 knots only.
The official forecast errors ranged from 43 n mi at 12 hours
to 175 n mi at 72 hours. The 1988-94 averages for such periods are
34 and 155 n mi respectively.