Tropical Storm Pilar formed just west of Mexico on Saturday. At 11:00 p.m. EDT on Saturday the center of Tropical Storm Pilar was located at latitude 18.7°N and longitude 105.3°W which put it about 120 miles (195 km) south-southeast of Cabo Corrientes, Mexico. Pilar was moving toward the north at 5 m.p.h. (8 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 1003 mb.
A Tropical Storm Warning was issued for the portion of the coast from Manzanillo to El Roblito including the Islas Marias.
A distinct center of circulation developed within a larger area of low pressure near the west coast of Mexico on Saturday and the system was classified as Tropical Storm Pilar. Several bands of showers and thunderstorms began to form around the center. Storms near the center started to generate upper level divergence which was pumping mass away to the west of Tropical Storm Pilar.
Tropical Storm Pilar will move through an environment that will be somewhat favorable for intensification on Sunday. Pilar will move over water where the Sea Surface Temperature is near 29°C. An upper level high over Mexico is producing easterly winds which are blowing toward the top of the circulation. Those winds are producing some vertical wind shear, but the shear was not strong enough to prevent the formation of Tropical Storm Pilar. The eastern part of the circulation will be moving over western Mexico and increased friction will be the primary factor inhibiting strengthening. Tropical Storm Pilar is likely to intensify on Sunday.
A ridge in the middle levels of the atmosphere over Mexico is steering Tropical Storm Pilar slowly toward the north. On its anticipated track the center of Tropical Storm Pilar will be very near Cabo Corrientes on Sunday night. The center could move inland or it could remain just west of the coast. Tropical Storm Pilar will drop very heavy rain over parts of the states of Colima and Jalisco. The heavy rain could cause flash flooding in some locations.