Slow moving low pressure situated over the St Lawrence Valley will rotate upper air disturbances through our area for much of Saturday.

The models maintain a chance of showers throughout the day on Saturday, with light  precipitation most likely in the early morning and again late afternoon with heavier thunderstorms.   During much of the daytime, showers will be widely scattered and we likely will have a fair amount of of sunshine through variable cloudiness.   Showers and thunderstorms will become more organized after 4 pm on Saturday.  Hot and humid conditions with highs near 90 on Saturday.

A cold front finally moves through Saturday evening, with a drop off in dew points and temperatures late.

Sunday looks to be partly cloudy/ partly  sunny and lower humidity  with high temperatures in the 80s.

Updated Friday 11 pm: The low pressure system in  the St Lawrence valley may redevelop off the mid Atlantic coast  giving us a chance of scattered showers Sunday afternoon.   

As mentioned in my forecast outlook earlier this week, high pressure was expected to move in and suppress a frontal boundary far enough to our south to give us a postcard perfect weekend. However, I had mentioned that a slight change in the frontal boundary position could change that perfect forecast.

WIth today’s model runs, it appears that  high pressure won’t push far enough south; as a result, clouds and a chance of showers may make their appearance Sunday afternoon and Monday as low pressure moves along the stalled front.

There are large differences between the NAM and GFS models regarding timing of the showers, wth the GFS moving the showers in Sunday afternoon while the NAM waits for Monday.

Either way, Saturday will be the best day, with sunny skies and pleasant temperatures in the low 80s.

Sunday and Monday look to be mostly  cloudy with showers looking more likely.  I’ll update late Saturday to see if things are better defined.

Saturday 7AM update: There is still uncertainty about precipitation chances for late Sunday and Monday, with significant differences between the NAM and GFS models.