We have been spoiled here in Philadelphia for the past week without a head wave coming in sight due to the jet stream going north into Canada. That's going to change come this week because of a high pressure moving in from the west and just stalling over the Northeast for almost this whole week. No chances for any precipitation is in sight either for us. This high pressure will make temperatures start to increase today (Saturday) into the mid 80s (Since the winds are out of the north). Then tomorrow, the winds will shift out of the west (where the warmer air is) and make things really start to heat up! Tomorrow (Sunday), temperatures will start to get into the low 90s but the good thing about it is that there shouldn't be high humidity. Monday-Thursday looks to stay in the low to mid 90s (92-94ºF) and then finally Friday drops down to the mid 80s. Some forecasts are calling for the chance of thunderstorms while others are saying mostly sunny. We'll see what happens and I will update you on that if anything chances.