As for today, an upper level low centered over Virginia will continue to spread a batch of rain off the Atlantic ocean north-northwest further inland. Areas of steady rain will be over th city and Long Island and last for several hours, with the steadiest rain holding on longest into on Long Island. There is a chance that extreme eastern Long Island could remain in a steady rain for most of the day (from East Hampton eastward, if this does pan out they could receive up to an inch of rain today).
Rainfall from this band will range from 0.25-0.50 inch. There are some lightning strikes in the band of rain, but for the most part, it will only be a rumble of thunder and not a strong thunderstorm. This area of rain will continue to spread out and elongate to a broken line of showers once it passes north of area.
Behind this area of rain, showers and possibly a thunderstorm will develop from the heating of the sun. Even though it will remain cloudy all day, the sun will help destabilize the atmosphere and spark showers. This afternoon will be drier, but still with a chance of showers. Rainfall amounts for the day today could reach up to three quarters of an inch with higher amounts possibly over eastern Long Island.
The locations with the best chance of hitting the upper 60s will be areas that do not receive an afternoon shower.
Tonight, the upper level low will be centered over eastern Pennsylvania, keeping our sky cover mostly cloudy and allowing our temperatures to hold steady overnight. With the sun setting, the coverage of showers will decrease throughout the night but not totally dissipate, so a chance of showers remains tonight.
Low temperatures will remain in the upper 50s, which is about 5-7 degrees above normal.
Tomorrow, the upper level low will move into New England and our winds, which have been persistently out of the east, will switch to southwest. This wind shift will dry out the low levels, since the wind will not be blowing from the cool Atlantic Ocean, so temperatures will reach the low 70s, but cooler along Long Island.
With the upper level low being close enough and the sun destabilizing the atmosphere a chance of a showers and thunderstorms is still possible however, it will not be as wet as today. The best chance of the thunderstorms will be during the afternoon due to the heating of the day.
Friday will be the warmest day of the week, ahead of an approaching cold front from the west. Temperatures will be in the upper 70s and could push 80 degrees. With the cold front approaching, the chance of thunderstorms will generally be in the afternoon. The thunderstorms don't pose a threat to severe weather, but could produce heavy rainfall with frequent lightning.