Chantal strength steady, but still disorganized

Satellite image taken at 7.37 p.m. EDT Sunday.

MIAMI, Florida (CNN) -- Tropical Storm Chantal maintained its near-hurricane level strength on Sunday, despite being "disorganized and struggling," according to the U.S. National Weather Service.

Chantal's maximum sustained winds were clocked at 70 mph (110 km/h), according to the latest NWS report, with some stronger gusts. A tropical storm gains hurricane status when its wind speed reaches 74 mph (118 km/h).

At 8 p.m. EDT, the NWS reported Chantal's "very poorly defined center" was 380 miles (610 km) east-southeast of Chetumal, Mexico. It was moving to the west-northwest at nearly 16 mph (26 km/h).

CHANTAL INFORMATION At 8 p.m. EDT Sunday STATUS Tropical storm POSITION 16.7 degrees north latitude, 82.8 degrees west longitude, 380 miles (610 km) east-southeast of Chetumal, Mexico MOVEMENT West-northwest at near 16 mph (26 km/h) WIND SPEED Sustained winds near 70 mph (110 km/h) OUTLOOK No major change expected today, but Chantal could gain hurricane status Monday WARNINGS Hurricane watch discontinued for Cayman Islands, but tropical storm warning remains in effect; hurricane watch issued north of Belize City, Belize, to Cancun, Mexico; tropical storm watch is in effect from Belize south of Belize City. EXTRA INFORMATION In-Depth: Hurricanes

Tropical storm force winds extended 175 miles (280 km) outward from the storm's center, mainly to the northeast.

Belize and Mexico's Yucatan Peninsula braced for the storm's arrival as it passed to the south of Jamaica on its way into the western Caribbean.

A hurricane watch has been declared from Belize City, Belize, northward to Cancun, Mexico, the service said. A tropical storm watch remained in effect from Belize City south to the Guatemala border.

The government of the Cayman Islands has discontinued its hurricane watch, according to the NWS, although a tropical storm warming remains in effect.

The storm may gain more strength during the next 24 hours, possibly becoming a hurricane early Monday.

The weather service said the storm could yield rainfall totals of 3 to 5 inches, with heavier amounts in mountainous areas.

Chantal is the Atlantic's third named storm this summer.

The Atlantic has yet to see a hurricane this season, which began in June. Two other tropical storms, Allison and Barry, made landfall along the northern Gulf Shore of the United States with heavy rains and flooding.

Allison's 12-day march from Texas to New England left 35 people dead and caused more than $1 billion in damage.