Not one but two low pressure fronts will impact the region, with rain dominating early Saturday. And while Sunday should be sunny, more rain could arrive on Monday, the National Weather Service in Islip said.
Cautions for drivers include fog, mainly before noon, and while Nassau is not under a flood advisory, everywhere in Suffolk — except for the northwest area — should be on guard for minor flooding during high tides from Saturday morning through the afternoon, the weather service advised.
Saturday's high will reach the upper 50s. However, the wind will be a factor, with gusts expected to hit 36 mph. And there is, the weather service said, a 20% chance that umbrellas will be needed before 9 p.m.
Up to 3.44 inches of rain had already fallen in Woodbury by 7 a.m. Saturday, according to unofficial observations reported by the weather service. In Suffolk County, rainfall totals ranged from 1.04 inches in Orient to 2.9 inches in Lake Ronkonkoma.
Impacts of the rain were being felt Saturday morning. The westbound Long Island Expressway was closed east of Exit 49 due to road flooding around 4 a.m., Suffolk police said in a tweet. The road has since reopened.
Sunday will clear and be about 10 degrees colder. It is expected to be breezy, with a west wind clocking in around 24 mph.
Clouds arrive Sunday night, giving Monday a 30% chance of rain, most likely after noon, the weather service said. Thermometers will drop to the upper 30s, only to rise to the low 40s during the night, when the odds of rain for Long Island rise to a near certainty: 90%.
"With cold air remaining at the surface and warmer air moving in aloft, a wintry mix of precipitation is likely for the interior mainly Monday afternoon and night, with primarily rain for New York City and Long Island," the weather service said.
That rain likely will continue into Tuesday, mostly before midday, the forecasters said. The high is expected to be near 48 degrees.
But the Wednesday to Friday stretch should offer clear skies, with temperatures in the mid 30s.