Philly Weekend Weather Forecast

Last Updated

Uncertainty in the forecast this weekend, especially with the amount of cloud cover on Sunday. The NAM is much wetter on Sunday with a chance of showers both morning and late afternoon. The GFS is dryer, more sun.

An interesting pattern change starts setting up over the weekend, as an amplified jet stream trough begins to develop over the Great Lakes and weak disturbances begin to rotate through our area as a cold front slowly advances. This amplified pattern is something we usually start seeing late August, not July, but it’s been a somewhat consistent feature of our cooler weather this entire year.

The timing and intensity of the these upper air disturbances around this developing trough are difficult to model and that’s where there is great uncertainty in this weekend’s forecast. That said, the GFS has done better than the NAM in recent weeks, so I’m thinking that Sunday will be drier and warmer than depicted by the NAM.

This amplified trough will eventually bring cooler temps and lower humidity to our area next week.

 

Sat 7/26: Cloudy in the morning, then bright spots, breaks of sun around noon, then increasingly cloudy with a chance of a shower or thunderstorm. High 84.

Sun 7/27: Mostly cloudy, some bright spots mid-day, then increasingly cloudy with showers by evening. Warm and humid. High temp will depend upon amount of sunshine…85 possibly warmer to 89.