Tropical Storm Isaac is expected to reach the mid-Atlantic by Tuesday and Wednesday, but it may not be packing the moisture it is expected to dump from Lousiana to Indiana.
Hydrometeorology models show nearly 8 inches falling on parts of Illinois and Indiana as remnants of what is now still a tropical storm moves to the northeast. But the models only predict a tenth of an inch to half an inch of rain across Maryland through Tuesday.
Local forecasters at the National Weather Service's Sterling, Va., office are calling for a 40 percent chance of thunderstorms from Sunday through Tuesday night.
August has already seen buckets of rain, with nearly 6 inches at BWI Marshall Airport, almost 3 inches more than normal. It will be the first month this year with above-average rainfall.
Meanwhile, two other storms are intensifying, but neither is currently expected to reach land.
Tropical Storm Leslie formed Thursday afternoon, with up to 40 mph winds as of 2 p.m. The storm is about 1,200 miles east of the Windward Islands of the eastern Caribbean.
Leslie is the second-earliest 12th Atlantic storm of the season, behind Hurricane Luis, which formed as a tropical storm Aug. 27, 1995.
Tropical Storm Kirk reached hurricane status as of 11 a.m., with winds up to 75 mph.
The heart of hurricane season lasts for about another two weeks.