A thick coat of the algae has plagued the lake in recent years, so large in the summer of 2011 it covered a sixth of the lake's surface, they said.
The extent of the spring rains will be an accurate predictor of the seriousness of the problem, researchers said; the greater the amount of rain, the greater the resultant summer algae growth.
The signs are not good, with Accuweather predicting a wetter than usual March and April throughout the region, The New York Times reported Friday.
In 2011, the wettest spring on record, the toxic summer algae bloom stretched nearly 120 miles, from Toledo to past Cleveland, experts said.
Lake Erie's problems began in the 1960s with the mostly unregulated dumping of sewage and industrial pollutants, leading to a multibillion-dollar cleanup by the United States and Canada.
But the algae blooms have returned, due to phosphorus from agricultural runoff that the algae thrive on.
"We've seen this lake go from the poster child for pollution problems to the best example in the world of ecosystem recovery. Now it's headed back again," Jeffrey M. Reutter of Ohio State University said.