We’re once again in luck of some nicer, cooler days to finish the work week.  We can thank a cold front that passed through the bi-state early today, bringing a dip in humidity and providing a more comfortable, drier air mass for the St. Louis area.  As the sky clears tonight, temperatures will quickly drop off with a much cooler overnight period around 60º.  Tomorrow is beautiful and our coolest day of the extended period with highs just topping 80º.  Summer heat and humidity ramp up by the weekend with southerly flow returning by Saturday.  Highs Saturday and Sunday will be much hotter in the 90s with heat indices back around 100º.  T’storm chances return later this weekend as well with an approaching frontal system.  By next work week, we’re given yet another break in the heat with highs running well below average around the 80º mark. -Anne Elise Parks, @anneeliseparks