Tropical Depression Twentyeight strengthened to Tropical Storm Zeta over the northwestern Caribbean Sea early on Sunday. At 8:00 a.m. EDT on Sunday the center of Tropical Storm Zeta was located at latitude 17.8°N and longitude 83.8°W which put it about 275 miles (445 km) southeast of Cozumel, Mexico. Zeta was nearly stationary. 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 1005 mb.

The government of Mexico issued a Hurricane Watch for the coast of the Yucatan Peninsula from Tulum to Rio Lagartos and for Cozumel. The Hurricane Watch included Cancun. A Tropical Storm Warning was in effect for the Cuban province of Pinar del Rio.

Based on data from a NOAA airplane and a scatterometer on a satellite, the National Hurricane Center determined that Tropical Depression Twentyeight had strengthened to Tropical Storm Zeta over the northwestern Caribbean Sea early on Sunday morning. The circulation around Zeta was still not well organized. The circulation in the middle troposphere was located to the east of the surface center. The lower level circulation seemed to be shifting closer to the middle level circulation and it was possible that a new center could be developing under the middle level rotation. Bands of showers and thunderstorms were revolving around the middle level center. Storms near that center were generating upper level divergence which pumped mass away from the tropical storm. Data from the airplane indicated that winds to tropical storm force were occurring southeast of the center of Zeta. The tropical storm force winds extended out about 80 miles (130 km) from the center of Zeta.

Tropical Storm Zeta will move through an environment favorable for intensification during the next several days.  Zeta will move over water where the Sea Surface Temperature is near 29°C.  It will be under an upper level ridge where the upper level winds are weak and there will be little vertical wind shear.  If Zeta remains stationary for another 12 to 24 hours, its winds will mix cooler water to the surface, which could interrupt intensification. Tropical Storm Zeta will intensify during the next 24 hours and it could strengthen to a hurricane early next week.

Tropical Storm Zeta will be in an area where the steering winds are weak during the next 12 to 24 hours. Zeta could meander over the northwestern Caribbean Sea during that time. A ridge of high pressure will strengthen to the northeast of Tropical Storm Zeta later on Sunday. The ridge will steer Zeta toward the northwest on Monday and Tuesday. On its anticipated track Tropical Storm Zeta could pass near the northeastern tip of Yucatan Peninsula on Monday evening.

Elsewhere over the Atlantic Ocean, Hurricane Epsilon was passing south of Newfoundland. At 5:00 a.m. EDT on Sunday the center of Hurricane Epsilon was located at latitude 42.8°N and longitude 53.7°W which put it about 270 miles (435 km) south of Cape Race, Newfoundland. Epsilon was moving toward the northeast at 30 m.p.h. (48 km/h). The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (145 km/h). The minimum surface pressure was 960 mb.