Tropical Storm Bertha formed in the Gulf of Mexico on Monday evening and forecasters warned that the system was likely to bring heavy rain to states throughout the region his week.

Tropical storm watches were in effect along the Gulf Coast as the system churned nearby.

Forecasters said the storm was expected to continue moving slowly toward the northwest over the next day or two, before gradually turning west. The center of the system could then move near or along the northern Gulf Coast over the next several days.

Tropical Storm Bertha is the second of this year’s Atlantic hurricane season. A storm gets a name when wind speeds reach 39 miles per hour. It becomes a hurricane if it reaches 74 m.p.h.

The season started on June 1 and runs through Nov. 30 and was predicted to have fewer storms than in recent years, according to the National Oceanic and Atmospheric Administration last month. This year’s only other named storm, Tropical Storm Arthur, dumped heavy rain along the western side of the Gulf Coast last month.

A tropical storm watch was in effect for most of the Gulf Coast from the Florida Panhandle to eastern Louisiana.

Forecasters said additional watches or warnings might be issued over the next day or two, as the system develops and its path becomes more certain. Strong winds could begin affecting the watch areas by late Monday, if the system continues to strengthen as expected.

Storm surge is also a risk along parts of the Gulf Coast, especially if the peak surge arrives at the same time as high tide. A storm surge watch was issued from the Alabama and Florida border west to the mouth of the Mississippi River in Louisiana. Water levels could rise between two and four feet above ground from the mouth of the Mississippi River to the Alabama and Florida border, while one to three feet of storm surge is forecast from Morgan City, La., to the mouth of the Mississippi River, around Lake Pontchartrain, and along parts of the Florida Gulf Coast, from Indian Pass south to the Chassahowitzka River.

Heavy rainfall is also expected to be a hazard. Through Friday, much of the eastern and central Gulf Coast — including western Florida to the middle Texas Coast, including southern parts of Alabama, Mississippi and Louisiana — could receive two to four inches of rainfall. Some isolated locations could receive up to eight inches. The heavy rainfall could lead to flash flooding, especially in urban areas.

Swells generated by the tropical depression are already affecting parts of Florida’s Gulf Coast and are expected to spread westward along the Gulf Coast during the week. These waves could create dangerous surf and life-threatening rip currents, forecasters said.

Forecasters said there was also the threat of one or two tornadoes on Monday, across Florida’s Big Bend region, as the system moves through the Gulf of Mexico.