Today should see the last of what is now nearly a week of temperatures in the 90-degree range, forecasters say. A cold front now moving into the Ohio Valley will move our way overnight tonight and drop the daytime highs back to the lower half of the 80s well into next week.

But it may well be a wet transition, as the relatively cool Canadian air runs up against this hot, humid Gulf air that we've been sweating in for several weeks. Some of that rain is already visible on radar in the western part of Maryland (above).

Looking back, Baltimore's average daily temperatures have been 1 to 8 degrees above the long-term averages since Aug. 9. Since the 16th, our daytime highs have ranged between 87 and 93 degrees. The "normal" highs at this time of year are around 85 degrees. We're looking at a high of 92 degrees today at the airport, followed by just 82 on Saturday. 

But we'll have to endure a bath to cool off. Forecasters out in Sterling say we're looking at a 60 to 70 percent chance for showers and thunderstorms from late Friday through Saturday night. Some locations may see heavy, prolonged downpours in persistent "training" thunderstorms that form and reform over the same places.

The front will stall here for a time until Hurricane Bill picks up speed and moves out of the way. That will clear the decks for the front to pass through, and admit the cooler, drier Canadian air by Sunday.