The remnants of Tropical Storm Bill are forecast to reach the mid-Atlantic this weekend, and, combined with showers and storms forecast in the coming days, could bring the region 2 inches of rainfall from now through Father's Day.
A weather pattern known as a "Ring of Fire" is already bringing repeated chances for showers and storms. Storm chances are forecast Wednesday night and Thursday.
The pattern refers to storms forming along the edges of a zone of high pressure, in this case up the Mississippi River valley and across the Ohio River valley into the mid-Atlantic.
But by late Saturday, what is left of Bill, which is currently a tropical depression, is forecast to reach Maryland. Meteorologists in the National Weather Service's Baltimore/Washington forecast office say heavy rain is likely Saturday night into Sunday.
There is also a low risk of severe storms as the system moves through, the forecasters say.
The weather service's precipitation forecast models suggest an inch and a half to two inches of rain across the region within the next five days. The heaviest rain is expected along the Mason-Dixon Line.
There has already been nearly 5 inches of rain so far this month at Baltimore-Washington International Thurgood Marshall Airport, almost an inch and a half more than normal for the entire month.