A flash flood watch is in effect for Nassau and Suffolk counties until 10 p.m. Friday as showers and possibly a thunderstorm dump from 1 to 3 inches of rain -- and possibly more in isolated areas -- on Long Island during the Independence Day holiday, the National Weather Service said.
A cold front moving slowly into the area will interact with moisture carried by Hurricane Arthur as the day goes on, forecasters said.
The main impact is expected to be flooding of urbanized and low-lying areas, particularly areas with poor drainage, the forecasters said.
"There is a high risk of rip currents through today," Joe Pollina, a meteorologist at the weather service in Upton, said Friday morning. "Wind and wave conditions will create the risk of very strong rip currents, which can be dangerous to anyone who enters the surf. So you should swim where there are lifeguards."
"As Arthur passes well south and east, there will be high surf, dangerous rip currents and dangerous boating conditions in the ocean and inlets late today and into Saturday," Pollina said.
The heaviest rain should hit eastern Long Island, he said, with lesser amounts toward western Nassau County. The chance of showers should continue until about 9 p.m., according to the forecast.
The rain over New York City was expected to end well before the start of the Macy's fireworks show.
Almost 3 inches had fallen in parts of eastern Suffolk by 7 p.m., said Tim Morrin, another meteorologist in the Upton office.
But the wet weather has erased the year's "rain deficit" of 2.25 inches on the Island, he said. The Island was at least .3 inches of rain above normal by Friday night, he said.
For the weekend, puffy white clouds will float in mostly sunny skies as temperatures hover in the low 80s, Morrin said: "That might be our consolation prize for dealing with a wet Fourth."
With Ellen Yan