Last night was a foreshadowing of what's in store for this week's weather so Gothamist made this beautiful chart. We like making graphs! Yesterday was a steamy day with temperatures in the high 80s and dew points in the mid-60s. Late afternoon the temperature started falling as it normally does, when, around 4 o'clock, it starts getting warmer. That's kind of unusual, but the falling dew points give away the story. The cold front that had been lurking to the north of the city all day had slunk to our south and the dry air allowed for a little late day warming.

Following the sunset it cools off rapidly for an hour as radiative cooling takes place. But wait, the cold front retreats back north. The temperature and humidity rebound. Around 3 a.m. the dew points start plummeting. The cold front has finally managed to push the warm, moist air to our south. Or has it?

The weather is going to be right on the edge this week. Cooler, dryer air sits to our north. Warmer, moister air sits to our south. A weak cold/warm front sits between the two air masses. Sometimes, like today and tomorrow, we'll mostly be in the drier air. When that happens we'll see mostly clear skies and highs in the mid-80s. Sometimes, like tomorrow night and Wednesday, we'll be in the moister air. Highs will still be in the mid-80s. In between those two situations we'll probably see showers. There's a slight chance of rain today and tomorrow. A much better chance exists Wednesday through Friday. This battle of the air masses, they are called fronts for a reason, may continue for a week or more.