A low pressure system over the southwestern Gulf of Mexico was designated as Potential Tropical Cyclone Six by the U.S. National Hurricane Center on Sunday afternoon. A Tropical Storm Watch was issued for the coast of northern Mexico. At 5:00 p.m. EDT on Sunday the center of Potential Tropical Cyclone Six located at latitude 21.6°N and longitude 94.6°W which put the center about 340 miles (545 km) south-southeast of the Mouth of the Rio Grande River. The low pressure system was moving toward the northwest at 5 m.p.h. (8 km/h). The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 60 m.p.h. (95 km/h). The minimum surface pressure was 1003 mb.
A Tropical Storm Watch was in effect for the portion of the coast from Barra del Tordo,, Mexico to the Mouth of the Rio Grande River.
A U.S. Air Force Reserve Hurricane Hunter reconnaissance aircraft investigated a low pressure system over the southwest Gulf of Mexico that was previously designated as Invest 91L on Sunday afternoon. The Hurricane Hunters found that there was a large low pressure system with a broad counterclockwise rotation. The reconnaissance flight was unable to find a distinct low level center of circulation. The flight crew did find a large area of tropical storm force winds in the western side of the low pressure system.
Winds to tropical storm force extended out 185 miles (295 km) in the western side of Potential Tropical Cyclone Six. The winds in the eastern side of the low pressure system were blowing at less than tropical storm force.
The strongest winds in Potential Tropical Cyclone Six were occurring in bands of thunderstorms in the southwestern part of the low pressure system. The bands in the other parts of the circulation consisted primarily of showers and lower clouds. The storms in the southwestern part of Potential Tropical Cyclone Six began to generate upper level divergence that pumped mass away from the low pressure system.
Potential Tropical Cyclone Six will move through an environment mostly favorable for the intensification during the next 24 hours. The low pressure system will move over water where the Sea Surface Temperatures are near 30°C. It will move over the eastern part of an upper level ridge over northern Mexico and the western Gulf of Mexico. The upper level ridge will produce northwesterly winds that will blow toward the top of Potential Tropical Cyclone Six’s circulation. Those winds will cause some vertical wind shear. The wind shear will inhibit intensification, but the shear will not be enough to prevent intensification. The large size of the circulation around the low pressure system will also reduce the rate of intensification. Potential Tropical Cyclone Six is likely to intensify slowly during the next 24 hours. The low pressure system could intensify more rapidly after an inner core forms.
Potential Tropical Cyclone Six will move around the southwestern part of a high pressure system that extends from the western Atlantic Ocean to the Gulf of Mexico. The high pressure system will steer the low pressure system toward the northwest during the next 24 hours. On its anticipated track, Potential Tropical Cyclone Six will move toward northern Mexico. The low pressure system will move more toward the north on Tuesday when it moves around the western end of the high pressure system. It is likely to be southeast of Texas on Tuesday night. Potential Tropical Cyclone Six could approach the coast of Louisiana on Wednesday. It could be a hurricane when it approaches the coast of Louisiana.