A flash flood watch is in effect for parts of Maryland through Friday morning.
Drizzle and some showers are expected to continue across Central Maryland into Saturday, but fears of widespread flooding did not materialize Thursday as the heaviest rain fell on the southernmost portions of the state.
Rainfall surpassed 3 inches in parts of the Baltimore region from Wednesday night through Thursday morning, with 3.83 inches reported in Rosedale and 3.3 inches in Elkridge, according to the National Weather Service.
About 2.6 inches fell at Baltimore-Washington International Thurgood Marshall Airport, the region's point of record, including more than an inch during the morning rush hour, contributing to major traffic problems. Interstate 695 was closed in both directions near the Key Bridge after a tractor-trailer overturned. Another crash was reported on the northbound Jones Falls Expressway near the Pepsi sign in Woodberry.
After that, the heavy precipitation steered clear of the Baltimore region, though there were lingering risks of flooding overnight.
The massive low-pressure system bringing rainy and unsettled conditions across the eastern part of the country delivered its heaviest precipitation across Southern Maryland and the Eastern Shore. By 5 p.m., more than 7 inches had fallen in Prince Frederick in Calvert County, while Salisbury saw nearly 5 inches and Ocean City nearly 4 inches.
A flash-flood watch was canceled on Thursday after the threat of heavy rainfall appeared to have passed. Most of the rain was concentrated over the Shenandoah Valley in Virginia and in Delaware, said Dan Hofmann, a meteorologist with the weather service's Baltimore/Washington forecast office.
"Although there will still be periods of showers over the next day or two, the possibility of heavy rain has diminished to the point where we no longer need the watch," he said. "The highest risk for flooding has passed."
Rain chances are forecast to taper off by Friday morning, though conditions should remain gloomy, with winds blowing in from the Atlantic. Damp and windy conditions are forecast throughout the day, with gusts up to 25 or 30 mph, said NWS meteorologist Bryan Jackson. More showers are possible Friday evening and early Saturday.
After that, tranquil and seasonable weather is forecast to return Sunday and through most of next week.
But the specter of a tropical storm or hurricane looms by the end of the week.
The tropical system named Matthew became this year's fifth Atlantic hurricane early Thursday afternoon, and forecasters expect it to make a northward turn over the next few days.
The hurricane had maximum sustained winds of 75 mph at its core, centered in the Caribbean Sea several hundred miles south of Puerto Rico.
By Saturday, forecasters predict it will turn northward toward Jamaica and Cuba, potentially reaching the Bahamas by Tuesday.
It's too early to predict its track beyond that, but forecasting models suggest it could make its way up the Atlantic coast. Meteorologists at the National Weather Service office in Wakefield, Va., which covers Ocean City and the lower Eastern Shore, said the storm poses some "uncertainty" in the long-term forecast.
"Some of the computer guidance has it approaching the region, perhaps moving along shore or out to sea," Jackson said. "It bears paying attention to it."