After some morning showers and clouds we did have sunshine by lunchtime; by the mid-afternoon we did have clouds pop back up along with showers and severe thunderstorms north and west by dinnertime. We did reach a high of 91 at Philadelphia International Airport after a low of 72 in the morning. Showers and thunderstorms will continue overnight with lows in the lower 70s with even some fog forming as well.
Monday will continue to be humid with showers and thunderstorms in the afternoon as the frontal boundary continues to push eastward; highs will be in the lower 90s with a southerly wind around 10mph; the issue will be that there will plenty of instability aloft and there is a slight risk for severe thunderstorms with large hail and gusty winds possible. This will continue overnight Monday with lows in the middle 70s and also into Tuesday with highs in the lower 90s as the frontal boundary washes itself out, but a more potent cold front approaches from the west.
Another risk for severe storms is on tap for Tuesday afternoon thanks to the upper-level(500-millibar, or 18,000 feet) low swinging on through. What this will do is create a lot of instability aloft and with the continued "juicy" airmass on top of the region it just takes the rising of air parcels to pop up a storm; there will also be strong wind shear aloft (wind direction and/or speed changing with height) that can cause gusty winds, large hail, and also the threat of a few spinups(funnel clouds and tornadoes). FINALLY overnight into Wednesday we'll begin to clear out the moisture as drier air will try and work in from the north.
We'll be under the influence of high pressure once again with unseasonably cool and dry air from Canada; highs will just be in the lower to middle 80s on Wednesday while overnight lows will be in the lower 60s; Thursday will barely reach 80 with overnight lows in the upper 50s! That's almost TEN degrees BELOW average! It will feel more like Mid-September than Mid-July! You will be able to give your air conditioner a rest for a few days!
Friday's in the lower 80s with plenty of sunshine, but then the humidity creeps back in for the weekend; Saturday will be in the middle 80s and then there is a risk for showers and thunderstorms in the late evening and lasting through Sunday with overnight lows near 70 and afternoon highs in the upper 80s.
For now you can view my 7-day forecast(any time) at www.scottderekwx.com/forecast.html.