Tropical Storm Pilar Moves South of Mexico

Tropical Storm Pilar moved south of Mexico on Thursday evening. At 11:00 p.m. EDT on Thursday the center of Tropical Storm Pilar was located at latitude 10.7°N and longitude 99.2°W which put it about 465 miles (750 km) southwest of Salina Cruz, Mexico. Pilar was moving toward the west-southwest at 22 m.p.h. (35 km/h). The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 75 m.p.h. (120 km/h). The minimum surface pressure was 998 mb.

There were not a lot of thunderstorms in the circulation around Tropical Storm Pilar on Thursday evening. A few thunderstorms persisted in a band on the northern side of the center of Pilar’s circulation. Bands in the other parts of Tropical Storm Pilar consisted primarily of showers and lower clouds. The circulation around Tropical Storm Pilar was small. Winds to tropical storm force extended out 80 miles (130 km) from the center of Pilar.

Tropical Storm Pilar will move through an environment that will be unfavorable for intensification during the next 24 hours. Pilar will move over water where the Sea Surface Temperatures are near 29°C. It will move under the southern part of an upper level ridge over the Gulf of Mexico. The upper level ridge will produce northeasterly winds that will blow toward the top of Pilar’s circulation. A surface high pressure system that extends from the eastern U.S. across the Gulf of Mexico will produce strong northeasterly winds in the lower levels. The winds in the lower levels of the atmosphere will be stronger than the winds in the upper levels. The difference in wind speed will cause moderate vertical wind shear. The wind shear will inhibit intensification. In addition, the high pressure system will continue to pump cool dry air over the Gulf of Tehuantepec. The effects of the cool dry air and the moderate vertical wind shear will cause Tropical Storm Pilar to weaken on Friday.

Tropical Storm Pilar will move around the southern part of the surface high pressure system. The high pressure system will steer Pilar toward the west-southwest during the next 24 hours. On its anticipated track, Tropical Storm Pilar will move farther away from Mexico on Friday.