Currently, at 500 hPa there is a longwave trough centered over Quebec and extending down into much of the eastern United States. This trough is associated with a frontal system that has passed offshore of the Eastern Seaboard. At Stony Brook, cloud cover will decrease tonight and wind flow will be from the west with a low temperature of around 45F. Tomorrow the 500 hPa trough will deepen in the Southeast, resulting in weak ridging and surface high pressure moving into Long Island during the day. This will result in mostly sunny skies and weak northwesterly flow at Stony Brook with a high temperature of around 57F. Tomorrow night the deepened trough will bring a strong surface low into the area, resulting in rain moving back in overnight.