A coastal low off the Mid Atlantic coast is producing widespread rain south of New Jersey, with its associated cloud cover extending north into the NYC area. The coastal low will depart tonight with a cold front approaching on Saturday, allowing for a brief spike in temperatures into the mid 40s-low 50s. A slight cool down is anticipated for Sunday followed by continued near average temperatures for Monday and Tuesday, but with temperatures expected to fall again late next week as a storm system likely affects the region (Image credit: PSU e-Wall).
Today – Sunday: Clouds Depart, Temperatures Warm Up
Posted above from left to right are the latest available surface analysis and radar composite from WPC, and the initialized GFS 500 millibar heights and vorticity from NCEP MAG; both are valid at 18z (1pm). The main feature to note in the eastern US is a strong low pressure off the coast of North Carolina, with a minimum pressure of 998 millibars. As the 500mb map shows, however, there is virtually no interaction with the northern stream, which is well to the north over Canada, with a lack of a fresh cold air source resulting in precipitation type primarily falling as rain except for higher elevations, where some mixed precipitation has occurred. This system will continue to slowly track NE and offshore, with mainly cloudy skies to continue today over the NYC area before clearing tonight.
Following the departure of the coastal low, a cold front near Minnesota will continue to slide east towards the region, with a west-WNW flow expected during the day on Saturday as the front moves through the area. With some sunshine expected, along with a relatively mild air mass ahead of the frontal passage, temperatures are expected to rise into the 45-50 degree range across most of the area, which is near to even slightly above average. A transient cool air mass will quickly transverse the region on Sunday behind this front, with mostly cloudy skies and highs in the upper 30s, along with a breezy NW wind at 10-15 mph.