A cold front currently over southeastern Canada this morning will drop south through the Philadelphia and New York City metropolitan areas over the next 48 hours, producing periods of showers and thunderstorms throughout the region that will linger on through the middle of next week.
Today, clouds will increase through the day as high pressure slowly gives way to the advancing cold front from the north. An isolated shower will be possible in the late afternoon and evening hours. Winds will veer from the northwest to the northeast at 5 to 15 mph. Temperatures will rise into the mid to upper 60's over Long Island, lower to mid 70's over the New York City metropolitan area and northern interior, and mid to upper 70's over the Philadelphia metropolitan area.
Tonight through tomorrow, clouds will increase leading to overcast skies throughout the region. Scattered showers and isolated thunderstorms will develop throughout the region. These thunderstorms will be capable of very heavy downpours, frequent lightning, wind gusts over 40 mph, and small hail. Winds will veer from the northeast to southeast at 5 to 15 mph as the cold front drops south and stalls over the region. Temperatures tonight will fall into the upper 50's to lower 60's for lows. Temperatures tomorrow afternoon will rise into the upper 60's to lower 70's over the New York City metropolitan area and mid to upper 70's over the Philadelphia metropolitan area.
Thursday on through Monday, the cold front boundary will stall over the region and act as a roadway for disturbances to drive through the region. These disturbances will produce showers and thunderstorms at times and variable cloud cover. The period will not be a wash out with rain all the time, but a constant threat for showers and thunderstorms will clearly be present. Low temperatures will range from the lower to mid 50's over the interior and upper 50's to lower 60's along the coast and in urban locations. High temperatures will range from the upper 60's to lower 70's over Long Island, lower to mid 70's over the New York City metropolitan areas, and mid to upper 70's over the Philadelphia metropolitan areas.