Despite being located over very warm sea surface temperatures and in a moist environment, Lester was unable to intensify further and remained a minimal tropical storm as it slowly approached the coast of Mexico, due to moderately strong wind shear.

Lester made landfall near Punta Maldonado in extreme southwestern Guerrero as a tropical depression around 12:00 UTC on September 17.

A fisherman died in Guerrero due to large waves from Lester capsizing his boat off the coast of the town of La Bocana.

An area of disturbed weather, characterized by sporadic convection, developed several hundred miles south of Mexico on September 13, along the monsoon trough.

Located in weak steering currents, the depression meandered to the northwest overnight, strengthening into a tropical storm at 06:00 UTC the following day and receiving the name Lester from the United States-based National Hurricane Center (NHC).

Lester reached peak intensity when it strengthened into a tropical storm, with maximum sustained winds of 40 mph (65 km/h) and a minimum barometric pressure of 1,005 mbar (29.7 inHg).

[5] Lester made landfall around 12:00 UTC that day over extreme southwestern Guerrero, near Punta Maldonado, to the northwest of Puerto Escondido, Oaxaca, with sustained winds of 35 mph (55 km/h).

[6] Lester's circulation rapidly unraveled as it interacted with the mountainous terrain of southern Mexico, and the cyclone dissipated completely over Guerrero later that day.

[1] The Mexican government warned of the potential for heavy rainfall, strong winds and high waves in the states of Guerrero and Oaxaca in advance of the cyclone.

Severe flooding, landslides and river runoff were all reported following the storm's landfall just west of the state border with Guerrero, particularly in the municipalities of Santa María Tonameca, San Pedro Pochutla, Candelaria Loxicha and Pluma Hidalgo.

[14] State authorities in Oaxaca requested an emergency declaration for over a dozen coastal municipalities impacted by Lester from the Mexican federal government.