CHICAGO (CBS) — Heavy rain and thunderstorms are on the way for the Chicago area.

According to CBS 2 meteorologist Ed Curran, showers are possible later Saturday morning and rain coverage will increase Saturday afternoon.

He said the heaviest rain will arrive Saturday night into Sunday.

There is a Flash Flood Watch in effect Saturday evening in Cook, DeKalb, DuPage, Grundy, Kane, Kendall, Lake, LaSalle, McHenry and Will counties. The watch will stay in effect until early Monday 1 a.m. Monday.

Heavy rain could bring 1.5 to 2 inches per hour with totals that could top out around 4 inches by the time the rain ends. River flooding is a concern as rivers are already swollen from rain a week ago, and the Des Plaines and Fox rivers remain under a flood warning.

High temperatures will stay in the lower 80s and upper 70s. The low temperature for Saturday night will be about 69 degrees.

Monday is expected to be mostly sunny, and rain is not predicted again until Wednesday.