BATON ROUGE (AP) — Rain in the Ohio and Tennessee valleys and snow melt in the upper Mississippi Valley are swelling the Mississippi River in Louisiana, but no flood threats are predicted so far.

At Baton Rouge on Thursday morning the river was reported at just over 20 feet. Flood stage at Baton Rouge is 35 feet and levees protect the city above that level.

A gradual rise in water levels is expected to continue during the next week and a half to a crest of 28.6 feet at Baton Rouge by Jan. 12, according to a forecast released Wednesday.

The water levels are considered low right now, and the predicted crest shouldn’t be a problem, said Jim Ferguson, East Baton Rouge Parish drainage and bridge engineer.

‘‘Twenty-nine (feet) is no big deal,’’ Ferguson said.

The last time the Mississippi River at Baton Rouge reached flood stage was March 31. The river crested and went below flood stage in May.

Flood stage refers to the level of water a river must reach to overflow its natural banks if not for the protection from man-made levees.