High pressure that brought us sunshine and awesome weather for the weekend will be moving out over the Atlantic Ocean today, September 17th. The day will start off with plenty of sun but you will notice an increase in clouds this afternoon. Before the clouds roll in we should manage a high around 80, and it may be the last 80 degree reading we see in the near-term.
A strong cold front will move through the Delaware Valley on Tuesday, September 18th. Bring the umbrella with you because there will be periods of rain and thunder all day long, some of which could be heavy. The threat exists for damaging wind, so if you have outdoor plans for Tuesday you may want to consider rescheduling. The high will be in the upper 70s, but with clouds and rain around all day I think we'll come up just short of that 80 degree mark.
By the morning of Wednesday, September 19th, the cold front will be off the coast but there is a risk for a leftover shower or two. By the afternoon the sun will come out and mix with a few clouds. It will be a cooler day and feel more fall-like with a high near 75.
High pressure will start to build in to the Delaware Valley on Thursday, September 20th. We'll enjoy a mix of sun and clouds with a high near 75.
High pressure will be in full control on Friday, September 21st, providing us with a beautiful day under mostly sunny skies. The high will be in the mid 70s.
An approaching cold front could spawn a few showers on the first day of fall, Saturday, September 22nd. Otherwise, look for sun mixed with a few clouds and a high in the mid 70s. The autumnal equinox is at 10:49 AM Saturday morning.
The second half of the weekend looks nice and dry. Sunday, September 23rd, will feature scattered clouds with a high in the low to mid 70s.
Enjoy the warmth today before the rain comes in tomorrow. Be sure to check in with Phillyweather.net for updates!