As we approach the summer solstice, it is certainly going to feel like summer. The solstice is at 7:09 PM Wednesday evening, so the first full day of summer is on Thursday. The hottest day of the week will likely be Thursday when temperatures soar into the middle or, perhaps, upper 90s. The National Weather Service will likely issue excessive heat watches and warnings because the heat index will be near 100 degrees on both Wednesday and Thursday.
It will be a decent start to the week under a mix of sun and clouds. I can't completely rule out the chance of a thunderstorm, but most of the rain should stay west of I-95 today, June 18th. The high temperature will be in the mid-70s this afternoon. On Tuesday, June 19th, I am more confident that the thunderstorm activity will be west of I-95. A mix of sun and clouds is expected again, but temperatures and humidity will be on the increase. The high temperature will be in the mid-80s Tuesday afternoon.
By Wednesday, June 20th, a large bubble of high pressure will set up over the northeastern United States. This high will be originating from Bermuda, so very hot air will be associated with it. Wednesday will be hazy, hot, and humid with a high in the mid-90s. The heat index will be near 100 degrees. As of now, Thursday, June 21st, looks to be even hotter. I'll stick with 96 degrees, but I wouldn't be surprised if we get into the upper 90s Thursday afternoon, which means heat indices will be around 100 degrees or above. A cold front moving through on Friday, June 22nd, will bring temperatures down into the upper 80s and could possibly spawn a few thunderstorms.
The weekend is looking pretty good right now. Saturday, June 23rd, will be cooler and less humid under mostly sunny skies. The high temperature will be in the mid-80s. Sunday, June 24th, will be very pleasant with a mix of sun and clouds and a high around 80 degrees.
Feel free to track the heat this week at Phillyweather.net, and have yourself a great week.