The potential risk caused by a tropical disturbance over the Eastern North Pacific Ocean prompted the government of Mexico to issued a Tropical Storm Watch for a portion of the coast on Thursday afternoon. The U.S. National Hurricane Center designated the tropical disturbance as Potential Tropical Cyclone Four-E. At 5:00 p.m. EDT on Thursday the center of Potential Tropical Cyclone Four-E was located at latitude 11.3°N and longitude 100.2°W which put the center about 450 miles (725 km) south-southeast of Zihuatanejo, Mexico. The tropical disturbance was moving toward the west-northwest at 7 m.p.h. (11 km/h). The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h). The minimum surface pressure was 1006 mb.
A Tropical Storm Watch was in effect for the portion of the coast from Tecpan de Galeana to Manzanillo, Mexico.
A tropical disturbance over the Eastern North Pacific Ocean exhibited more organization on Thursday afternoon. Satellite loops appeared to show a counterclockwise rotation in the middle troposphere. It was unclear if there was a well defined center of circulation at the surface. Thunderstorms were occurring in bands in the northern and in the southern periphery of the tropical disturbance. There were few thunderstorms near the broad center in the middle troposphere.
The U.S. National Hurricane Center designated the tropical disturbance as Potential Tropical Cyclone Four-E and began to issue regular advisories on the system.
Potential Tropical Cyclone Four-E will move through an environment favorable for the formation of a tropical cyclone during the next 24 hour. The tropical disturbance will move over water where where the Sea Surface Temperatures are near 30°C. It will move under the middle part of an upper level ridge over southern Mexico and the adjacent part of the Eastern North Pacific Ocean. The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear. Potential Tropical Cyclone Four-E is likely to form into a tropical storm during the next 24 hours.
Potential Tropical Cyclone Four-E will move around the southwestern part of a high pressure system over Mexico. The high pressure system will steer the tropical disturbance toward the northwest during the next 24 hours. On its anticipated track, Potential Tropical Cyclone Four-E will move closer to the coast of southwestern Mexico.
Thunderstorms in bands in the northern periphery of Potential Tropical Cyclone Four-E will bring gusty winds and locally heavy rain to coastal portions of southwestern Mexico. The heaviest rain is likely fall in parts of Guerrero, Michoacan, and Colima. Heavy rain could cause flash floods in some location.
