Sun photo by Kenneth Lam - 2006 

Keep those unbrellas handy. The sunbathing is over and an approaching low-pressure system could drop an inch or two of rain on the Baltimore region between this afternoon and Friday night.

Forecasters say the low is tracking our way from the Mississippi valley, and it will be wet, tapping moisture streams from both the Gulf of Mexico and the Atlantic. That could mean a quarter-inch this afternoon, another inch - or two - overnight tonight into tomorrow.

Here's the radar loop.

There are no watches or warnings out in Maryland at this writing, but forecasters acknowledge they "may need to consider flood watch" in the next forecast update. There is also some talk in today's discussion from Sterling that if thunderstorms develop amid all this weather. "there's a decent chance they may start to spin" - a reference to a risk of tornadoes, at least in Central Virginia.

Once this system pulls away late on Friday, we'll get a short break. But Saturday looks like our only sunny day for a while. Another, similar storm system will move in on Sunday, with more rain later on Sunday into Monday - described by forecasters as "a decent soaker, not unlike the tonight/Friday system."

Forecast models then see another brief respite, followed by yet another rain system on Wednesday.