According to Tim Morrin, meteorologist with the National Weather Service office in Upton, a cold front passed through the area on Monday, with the coldest air delayed behind, causing temps to drop dramatically Monday night.
Temperatures on Tuesday are not expected to top the mid-teens, with some areas struggling to make 20 degrees, Morrin said; the normal high for this time of year is 38 degrees so the area is well below normal across the region, he said.
On Tuesday evening, parts of eastern Long Island will be battered by a coastal storm that's moving across the deep South.
"The storm is going to come just close enough that we'll be clipped from the Nassau/Suffolk border east," Morrin said.
From the William Floyd Parkway east, from two to four inches of snow is expected Tuesday night, with the chances for precipitation higher in eastern areas including Montauk Point and Orient.
Temperatures will continue to be cold, with a low of eight degrees, Morrin said, but the wind chill won't be a factor as winds have died down since Monday night.
Snow is expected to fall overnight and clear gradually by 9 or 10 a.m. Wednesday. Wednesday's temperatures are slated to reach a high of 26 degrees.