If you define a "heat wave" as three straight days of 90-plus weather, we may be on the verge of (only) our second heat wave of the year, and the first (and last) of the summer months.

Sounds odd, doesn't it? But you'll recall we had our first stretch of three 90-plus days (officially, at BWI-Marshall) way back in April. There were no 90-plus days in all of May and June, and July and August (so far) produced no more than two in a row.

But the forecasters out at Sterling are calling for highs of 93 degrees today, and 91 and 90 degrees on Wednesday and Thursday. So, we'll see if we can squeeze another "heat wave" into the summer before it ends (meteorologically speaking) on Aug. 30.

The next weather issue we'll face this week is rain. Showers and thunderstorms - some of them potentially with heavy rain - are in the cards for our area all week, with the highest probabilities (50 percent) tonight and tomorrow. The rain comes to us courtesy of a cold front which forecasters say will stall just to our northwest. That leaves us on the hot-and-humid side of the system, made even more unpleasant by the remnants of Tropical Storm Claudette, which went ashore in northwest Florida and Alabama over the weekend.

A hot sun and the tropical moisture, plus slow movement of the system, could mean very heavy rain totals once the storms fire up, forecasters warn. And that could produce some flash flooding issues as the days wear on.

The next break in the weather comes with the next, stronger, cold front, due here Friday or Saturday. That will come with more rain chances. But this front looks like the big August back-to-school break in the weather that brings us our first hint of autumn. Look for highs Sunday and Monday only about 80 degrees, with overnight lows in to 60s.

(NASA Photo/Aug. 17, 2009)