A line of showers and thunderstorms over the North Fork that began Saturday morning unexpectedly stalled and expanded west, quickly dumping up to 4 inches of rain in some Suffolk County communities and prompting a flash flood warning, the National Weather Service said.
The band of rain started to grow about 9 a.m. in the North Fork region, but it wasn’t yet widespread, said Jay Engle, a meteorologist with the service’s Upton bureau. Around 10 a.m., the storm started to grow in coverage area and expand farther west, and at about 10:30 a.m. it started to pick up across western and central Suffolk.
On the North Shore of Nassau County, localities were seeing about 2.5 to 3 inches of rain by 12:50 p.m., Engle said, while north central Suffolk and western Suffolk already had 3 inches. On the western part of the North Fork, estimates are as high as 4 inches, Engle said.
“It’s very hard to predict in the short-term,” Engle said. “The sheer intensity of the storm made the coverage grow from east to west back into Nassau County.”
Nassau County police said they received two calls about flooding. The first, at Central Avenue and Stewart Avenue in Valley Stream, was reported at 2:53 p.m. A police spokeswoman said callers reported a car stuck in standing water. About 8 inches of water was also reported at Plainfield Avenue and Hempstead Turnpike in Elmont at 2:59 p.m., the spokeswoman said.
The flash flood warning, issued by the weather service at 12:30 p.m., had expired by 3 p.m. It had included Huntington, Commack, Stony Brook, Centreach, Hauppauge, Smithtown, Centerport, Cold Spring Harbor, Farmingville, Lake Grove, Nissequogue, Huntington Bay, Old Field, Asharoken, St. James and East Northport.
A flood advisory had been in effect until 2:45 p.m. for minor flooding in poor drainage areas of northern Nassau, the service said just before 1 p.m.
The state Department of Transportation reported that Route 110 was closed briefly beginning about 11:30 a.m. because of flooding at Railroad Street-Broadway in Huntington Station.
“This isn’t that atypical in the summertime,” Engle said. “It’s just from the sheer intensity and the lack of movement — it’s moved over the same areas. The South Fork is not getting anything. It’s very localized. Everywhere south of the LIE, there’s not too much going on.”
The bureau was in storm mode, Engle said, examining data to determine the causes behind the storm. Engle had said preliminarily that the slow-moving storm could start to head north in the afternoon.
“In the late afternoon, the band could lift north but it’s slow-moving, and it’s crawling,” Engle said. “It should inch its way north as we go through time.”
Meanwhile, high humidity and above-average temperatures will blanket Long Island this weekend before a cold front Sunday night provides some relief, meteorologists said.
Temperatures are expected to rise to the lower to mid-80s across Long Island — upper 70s on the Twin Forks, said Peter Wichrowski, another meteorologist with the service’s Upton bureau.
A chance for pop-up showers and thunderstorms increases as the day wears on, he said.
“For today and tomorrow we’re a few degrees above normal, but certainly not the 90-degrees-or-above weather that we saw last week,” Wichrowski said Saturday.
The normal for this time of year is about 80 degrees at Long Island MacArthur Airport.
The chance of showers and thunderstorms is at its highest for the weekend on Sunday night following the cold front, said Matt Hammer, meteorologist with News 12 Long Island, when downpours and storms are expected.
“We’ll have a really refreshing feel Monday,” Hammer said, when temperatures fall to the upper 70s and low 80s and the humidity drops. The “nice summer stretch” of weather will last until about Thursday, when the humidity begins to increase again, Hammer said.
No advisories have been issued for the beaches, Hammer said, and the risk for rip currents is low this weekend.
A severe drought persists across parts of Suffolk County, the weather service said, because of rainfall deficits during the past several months.