(Updates strength, position, adds details, paragraphs 1-2, 6)
MEXICO CITY, June 25 (Reuters) - Tropical Storm Dora, located off the western coast of Mexico in the Pacific Ocean, is strengthening quickly and is expected to become a hurricane on Monday, the U.S. National Hurricane Center (NHC) said on Sunday.
Maximum sustained winds were about 70 miles per hour (110 km per hour), with higher gusts. Dora was strengthening quickly and was forecast to become a hurricane on Monday, the NHC said in its latest advisory late on Sunday night.
The NHC warned of possible heavy rains along the southwestern coast of Mexico but added that the center of the storm was expected to move parallel to the coast of Mexico but remain offshore. It said no coastal watches or warnings were in effect.
Dora was moving toward the west-northwest at around 14 mph (22 kph), and this general motion was expected to continue over the next 48 hours.
It was expected to produce rain accumulations of 1 to 3 inches (2.5 to 7.6 cm), with isolated maximum amounts of 5 inches along coastal sections of the Mexican states of Oaxaca, Guerrero, and Michoacan through Monday, the NHC said.
Dora was located some 290 miles (470 km) south-southeast of Cabo Corrientes, Mexico, at 11 p.m. EDT (0300 GMT), it said.
Parts of Mexico's Pacific coast were already hit by Tropical Storm Calvin earlier this month.
Calvin brought heavy flooding that led to a damaging fire at state-owned oil firm Pemex's Salina Cruz refinery, where operations are still suspended. (Reporting by Anthony Esposito and Chris Michaud; Editing by Bill Rigby and Paul Tait)