The Lakehead Region Conservation Authority has issued a flood watch and said there is potential for flooding based on a forecast of heavy rain over the next two days.

But no one is saying for sure where that rain, which is expected to start tomorrow afternoon, will fall. Geoff Coulson of Environment Canada said some areas could get a lot, and others not so much.

"The issue that we're dealing with right now is that there's probably going to be a very fine line — as there was with the last event on May 28 — between the areas that get significant rainfall, and the areas just 10-15 kilometres away that get significantly less," Coulson said.

"This is going to be another fairly well-defined — but narrow — area that gets the highest rain amounts."

Coulson said the current forecast is for localized rain amounts of up to 50 millimetres of rain, from later Tuesday through Wednesday morning.  According to the most recent mapping, the biggest amount could fall somewhere just north of Thunder Bay.  However, that could change.  The Conservation authority has also said localized thunderstorms could bring another 25-50 millimetres.

Late Monday afternoon, city officials in Thunder Bay said they are on alert, monitoring for flooding risks, and ready to deploy pumping equipment and staff resources following the new Flood Watch Warning.   "The City and its emergency partners have activated contingency plans to be in a state of readiness," Mayor Keith Hobbs said late Monday after a meeting of the Emergency Operations Control group.   If forecast rainstorms materialize over the next two days, workers will monitor the sewer system, as well as other infrastructure such as roads, bridges and trails, said Darrell Matson, general manager of infrastructure and operations.   "Depending on the specific locations affected, anticipated heavy rainfall could put added strain on the Water Pollution Control Plant. The plant continues to be staffed 24 hours a day to monitor the situation," Matson said.