Currently, at 500 hPa there is a longwave ridge over much of the eastern United States followed by a shortwave trough over the Great Plains. The ridge is associated with high pressure offshore while the trough is associated with a frontal system centered over Kansas with a long warm front extending east across the US and south of Long Island. Strong frontogenesis is occurring along this front, which will bring some light rain today to Stony Brook. This weather pattern will continue tonight and temperatures will remain relatively steady in Stony Brook with a low of around 45F and southeasterly flow. Rain will become more heavy overnight with a precipitation amount of around 0.4 inches. On Sunday the 500 hPa trough will move into the Great Lakes and rain will become lighter over Stony Brook as the warm front approaches but remains just south of Long Island. The high temperature will reach around 50F and an additional 0.1 inches of rain will fall, with southeasterly flow continuing.