Currently, at 500 hPa there is a longwave trough centered over Nova Scotia covering most of the northeastern United States, followed by weak ridging over the south-central US. The trough is associated with a surface low over Nova Scotia which was responsible for the unsettled weather over Stony Brook earlier today, while the ridge is associated with surface high pressure over the southeast US. Tonight, the strong northwesterly flow will drive the low temperature for Stony Brook down to around 38F with clouds diminishing through the night. The 500 hPa trough and surface low over Nova Scotia will continue to move to the northeast tomorrow, allowing the southeast high pressure to bring sunny skies and a high temperature of around 50F to Stony Brook, with northwesterly flow weakening. Calm weather will continue into Sunday before another 500 hPa longwave trough forms over the central US and returns rain to the northeast Sunday night.