Story highlights Woman is hospitalized after being hit by debris that crashes through window

Flash flood watches extend up the East Coast, from Florida to Maine

Washington and New York are among the cities that may see Andrea-related flooding

The forecast warns rains and storm surges could cause problems in coastal areas

There have been bigger storms before, with stronger winds. Still, Tropical Storm Andrea is already packing a wet wallop -- and it is expected to soak millions along the Eastern Seaboard by the time it runs its course.

It still packed damaging winds. A woman in Palm Beach County, Florida, was seriously injured Thursday night when she was hit by debris from an oak tree that flew through a bedroom window, the National Weather Service in Miami said.

Flash-flood warnings extended from the Sunshine State through coastal communities north to Virginia. An even broader swath of the East Coast -- including parts of 13 states, from Georgia to Maine -- is under flash-flood watches, meaning a sudden deluge of rain could overwhelm sewers, cause rivers and creeks to overrun their banks and more through the weekend.

Even Maine's coast, including Portland, could see as much as 3 inches of rain by the time this weekend is done.

JUST WATCHED Tropical Storm Andrea threatens Florida Replay More Videos ... MUST WATCH Tropical Storm Andrea threatens Florida 01:26

JUST WATCHED Can these drones hunt hurricanes? Replay More Videos ... MUST WATCH Can these drones hunt hurricanes? 02:25

All this comes from a storm that, as it passed through the Gulf of Mexico, never ascended to hurricane status -- it needed to have sustained winds of 74 mph or more to get that honor -- and then weakened, as far as wind speeds, as it passed over land Thursday evening.

As of 11 p.m. Thursday -- five hours after making landfall in the swampy, sparsely populated Big Bend region of Florida, about 180 miles north of Tampa -- Andrea was centered about 40 miles west of Jacksonville, Florida, and 65 miles east-southeast of Valdosta, Georgia.

The storm had maximum sustained winds of 45 mph, down substantially from when it made landfall, according to the National Hurricane Center.

Despite warnings that storm surges plus torrential rains could equal major flooding, Taylor County Emergency Management Director Dustin Hinkel said Andrea was bringing precipitation and high winds, but little trouble.

"We've had good luck with the storm coming ashore during low tide, so we have had some very, very minor coastal flooding so far," Hinkel said. "The rain has been very manageable here."

His county issued only a voluntary evacuation call as the storm neared, aimed at people living in mobile homes and older buildings, Hinkel said. No evacuations were ordered in Dixie County, to the south, said Tim Alexander, the emergency services director there.

On Thursday night, a tropical storm warning extended from Flagler Beach, Florida, to Cape Charles Light, Virginia. It's also in effect for the Pamlico and Albemarle Sounds and the lower Chesapeake Bay south of New Point Comfort, Virginia.

Such a warning means that tropical storm conditions -- with sustained winds in excess of 39 mph -- are likely within the next 36 hours. The forecast calls for Andrea to keep its strength "during the next day or so (before losing) its tropical characteristics by Saturday," the hurricane center says.

Andrea chugged inland over northern Florida on Thursday night, with wind and rain bands "spreading northward well ahead of the center," the Miami-based center reported.

The storm was then moving northeast at a 15 mph clip, with the forecast calling for it to move along even faster as it enters overnight into southeastern Georgia and eventually moves northeastward along the East Coast.

The projected path is similar to Tropical Storm Debby nearly a year ago. Debby dumped up to 2 feet of rain onto the low-lying region, causing extensive flooding in some coastal towns.

"The combination of a storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters," warns the hurricane center in its forecast.