It was a beautiful morning for watching the International Space Station fly over Baltimore and right past a gleaming Venus. But summer resumes this afternoon, with even hotter, muggier weather tomorrow. This early-autumn reprise of summer will be short-lived however.

The big mound of high pressure that's brought us these gorgeous days (which I've enjoyed through the sealed, double-paned windows of the newsroom) will be packing up and heading out to sea shortly. As it departs, Maryland will find itself on the west side of the clockwise circulation around the high. That will bring our air up from the south. Daytime highs today and tomorrow will rise toward 90 degrees and humidities will climb. It's going to feel a whole lot like summer.

As the high moves away, of course, it will be trailed by an approaching cold front and falling barometer. That will bring us increasing clouds and rising chances for rainfall late Wednesday and Thursday. Forecasters out at Sterling have been boosting their estimates. We're looking at 50 to 60 percent rain chances Thursday - showers and even a possible thunderstorm as the front and daytime heating stirs the air. Obviously, we need the rain, so every drop will be welcome. Right now this September ranks as the fourth-driest on record for Baltimore, with just 0.35 inch of rain on the meter at BWI, and 0.42 inch here at Calvert & Centre.

Once the front goes by, pressure will start to rise again Friday and cold air will pour in from the northwest. Skies will clear, and daytime highs will rise only into the mid-70s for the weekend, with sleeping-weather lows in the 50s. That's much more fall-like,  just about exactly in line with the long-term averages for Baltimore at this time of year.