Preliminary Report
Tropical Storm Gil
20-27 August 1995

PRELIMINARY REPORTS
Tropical Depression One-E
Hurricane Adolph
Hurricane Barbara
Hurricane Cosme
Tropical Storm Dalila
Tropical Storm Erick
Hurricane Flossie
Tropical Storm Gil
Hurricane Henriette
Hurricane Ismael
Hurricane Juliette

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 "best track" 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.

 

Table 1. Preliminary best track, Tropical Storm Gil, 20-27 August, 1995

Date/Time (UTC)	Position		Pressure (mb)	Wind Speed (kt)	Stage
	Lat. (°N)	Lon. (°W)
20/1800	15.5	99.1	1007	30	Tropical Depression
21/0000	15.7	100.0	1005	35	Tropical Storm
0600	15.8	101.5	1004	45	" "
1200	15.9	102.7	1004	45	" "
1800	16.1	104.5	1004	45	" "
22/0000	16.2	106.1	1004	45	" "
0600	16.2	107.4	1004	45	" "
1200	16.0	108.4	1004	45	" "
1800	15.8	109.2	1003	45	" "
23/0000	15.9	110.0	1002	45	" "
0600	16.2	110.6	1000	45	" "
1200	16.9	111.2	999	45	" "
1800	17.7	111.9	998	45	" "
24/0000	18.5	112.8	997	50	" "
0600	19.2	113.7	996	50	" "
1200	19.7	114.7	994	55	" "
1800	20.1	115.7	993	55	" "
25/0000	20.5	116.9	994	55	" "
0600	20.8	117.4	994	55	" "
1200	21.2	118.1	995	55	" "
1800	21.5	118.8	997	55	" "
26/0000	21.9	119.4	1000	50	" "
0600	22.0	119.6	1005	40	" "
1200	22.0	119.8	1008	35	" "
1800	22.0	120.0	1009	30	Tropical Depression
27/0000	22.0	120.1	1009	25	" "
0600	22.1	120.4	1009	25	" "
1200	22.7	120.4	1009	25	" "
1800					Dissipating
24/1800	20.1	115.7	993	55	Minimum Pressure