Upwards of 100 millimetres of rain could fall across much of southern New Brunswick over the next couple of days.

Rainfall warnings are in effect for a number of areas, including Saint John, Sussex, the Kennebecasis Valley, Kings County and Charlotte County.

Environment Canada says rain will move in on Wednesday night and continue into Friday morning.

Between 50 and 90 millimetres is expected, though forecasters said amounts could exceed 100 millimetres in some areas.

Forecasters said similar storms in the past have caused localized flooding and the overflowing of creeks and rivers.