Lester moved close, and parallel to, the coast of Mexico for several days, but
hurricane conditions remained offshore.
a. Synoptic History
The tropical wave responsible for the
origination of Hurricane Lester left Africa on 29 September. This wave initiated the development of
Hurricane Lisa in the tropical Atlantic Ocean on 5 October
midway between Africa and the Lesser Antilles. The wave itself continued westward, moving across Central
America on 11 and 12 October as a poorly-organized cluster of thunderstorms. A low-level circulation center
was first observed on satellite imagery on the 13th, in the eastern Pacific Ocean about 150 n mi south of the
border between El Salvador and Guatemala. This feature moved slowly northwestward as convection
increased near the center and a banding feature formed. It is estimated that
Tropical Depression Fourteen-E
formed at 0000 UTC on 15 October while centered about 175 n mi south of the coast of Guatemala. This is the
time of the beginning of the best-track of Hurricane Lester as shown in
Fig. 1 (24K GIF) and listed in Table 1.
Lester's track generally paralleled the coast of Mexico from the 15th through the 20th. The
track turned southwestward on the 22nd and northwestward on the 24th and dissipation occurred about 450 n
mi southwest of the southern tip of the Baja Peninsula on the 26th. On the large scale, the motion is toward the
west-northwest at 10 kt or less. This is consistent with the steering associated with a high pressure ridge which
was located to the northeast or north during Lester's existence. On a shorter time scale, a short wave trough
passed by to the north on the 17th, which slowed the forward motion to nearly stationary for several hours.
Another short wave trough slowed the motion to nearly stationary again on the 22nd. A ridge then built to the
north causing a motion toward the southwest for a day, followed by a resumption of a northwestward track.
The shape of the track closely resembles the shape of the coastline from the 15th through the
18th (Fig. 1). The track shape, along with its close proximity to the coast,
may be coincidental. Mexico is a mountainous country and the effects of this land mass on the track and intensity of a
tropical cyclone are not well known.
Lester's center moved to about 100 n mi
south of the Guatemala and Mexico coasts on the 15th, while it was a tropical storm.
Lester became a hurricane on the 16th and remained one until the 23rd.
The closest point of approach of the center to the coast was about 60 n mi south of Puerto Angel, Mexico on
the 17th and 18th. Its maximum 1-min surface wind speed reached 90 kt on
the 17th and remained near that speed through the 22nd, when it briefly reached 100
knots. It is possible that tropical storm force winds and some heavy rainfall reached the coast
between the Mexico/Guatemala border and Punta Maldonaldo. It is not believed that Lester was close enough
for hurricane conditions to reach the coast.
b. Meteorological statistics
U.S. Air Force reconnaissance aircraft
flew into the center on the 17th and 18th. This was a
test of international aviation clearance procedures. The highest wind speed reported by this aircraft was
98 kt at 700 mb on the 18th and the minimum central surface pressure was 973 mb.
Figs. 2 (23K GIF) and 3
(25K GIF) show plots of the best-track pressure and wind speed
curves, along with the reconnaissance data mentioned above and
Dvorak satellite intensity estimates.
Subjective Dvorak estimates were provided by the U.S.
Air Force Weather Agency (AFGWC),
the Tropical Analysis and Forecast Branch (TAFB) of the Tropical Prediction Center,
NWS and the Satellite Analysis Branch
(SAB) of NESDIS. The maximum wind speed of 100 kt on the 22nd is based
on satellite imagery showing a well-defined eye embedded in an area of cloud
tops of -60 to -70C.
There have been no observations received of strong winds on the coast of Mexico.
A series of radar images from the
Mexican National Meteorological Service radar at Puerto
Angel showed the northern half of an eye wall remaining off shore on the 17th and 18th.
c. Casualty and damage statistics
There have been no reports received of casualties or damage.
d. Forecast and warning critique.
For the official track forecasts issued while Lester was a tropical storm or hurricane, the
average track errors were 11, 32, 63, 94, 125, and 183 n mi, respectively for the 0-, 12-, 24-, 36-, 48-, and 72-h
forecast periods. There were 41 forecast cases verified at the 0-h forecast, decreasing to 29 cases at 72
hours. These errors are slightly smaller than the corresponding 1988-1997 average official errors at all forecast
There was a significant northward bias to the official track forecasts while Lester was near the
coast of Mexico. Much of the model guidance also had this bias as a result of forecasting a short wave trough
to erode the ridge to the north of the hurricane.
In the early stages, the official wind speed forecasts failed to capture the strengthening and
72-h wind speed forecast errors were as large as 65 knots.
The close proximity of the track to the coastline required the issuance of watches and warnings
from Sipacate, Guatemala westward to Punta San Telmo, Mexico. Tropical storm warnings
were issued east of Puerto Arista, Mexico and hurricanes warnings
were issued to the west of Puerto Arista to Acapulco. A hurricane watch
was issued west of Acapulco to Punta San Telmo. These actions occurred over the period
from the 15th to the 19th and are listed in Table 2.
Table 2. Watches and warnings issued for Hurricane Lester, October 1998.
|15/1500||tropical storm warning
||Sipacate, Guatemala to Puerto Arista, Mexico|
|tropical storm watch||west of Puerto Arista to Puerto Angel, Mexico|
|16/0300||tropical storm warning
||Puerto Arista to Punta Maldonaldo, Mexico|
|hurricane watch||Puerto Arista to Punta Maldonaldo|
|16/0900||hurricane warning||Puerto Arista to Punta Maldonaldo|
|16/1500||tropical storm warning discontinued||Guatemala|
||west of Punta Maldonaldo to Acapulco, Mexico|
|tropical storm warning discontinued||east of Puerto Arista |
||Salina Cruz to Acapulco, Mexico|
|hurricane watch||west of Acapulco to Zihuatanejo, Mexico|
|hurricane warning discontinued||east of Salina Cruz|
|19/0900||hurricane warning discontinued
||Salina Cruz to Acapulco|
|hurricane watch||Zihuatanejo to Punta San Telmo, Mexico|
|19/2100||hurricane watch discontinued||west of Acapulco to Punta San Telmo|