A broad area of low pressure is expected to form south of the Gulf of Tehuantepec later this week in association with a westward-moving tropical wave that is currently located south of Guatemala. Environmental conditions are forecast to be conducive for gradual development of the disturbance, and a tropical depression could form over the weekend while the system moves generally westward or west-northwestward at 10 to 15 mph, remaining well offshore of the coast of Mexico.