A flood watch is in effect Friday night through Sunday afternoon for portions of southeast Louisiana and southern Mississippi, the National Weather Service is reporting.
A warm front lifting northward from the Gulf of Mexico is expected to begin late Friday and interact with a moisture-rich southwesterly flow to bring an extended threat of moderate to heavy rainfall.
Widespread two-day rainfall could average between 2 and 4 inches with locally higher bands of rain possibly between 6 and 8 inches.
Some rivers may flood, and poorly drained areas may experience localized flooding.
The threat will end with a cold front late Sunday.
Affected parishes in the Baton Rouge area are: Ascension, Assumption, East Baton Rouge, East Feliciana, Iberville, Livingston, Pointe Coupee, St. Helena, St. James, Tangipahoa, Washington, West Baton Rouge and West Feliciana.
Affected parishes in the New Orleans area are: Jefferson, Lafourche, Orleans, Plaquemines, St. Bernard, St. Charles, St. John the Baptist, St. Tammany and Terrebonne.
Counties affected in southern Mississippi are: Amite, Hancock, Harrison, Jackson, Pearl River, Pike, Walthall and Wilkinson.