It won't last long, and it probably won't mess up your drive to Grandmother's house Thanksgiving morning. But holiday travelers should be aware that forecasters are calling for a period of sleet, and possibly some patches of freezing rain, north and west of the Baltimore-Washington corridor early Thursday.

The sleet doesn't show up at all in the forecast for BWI-Marshall airport. There is rain in the forecast, beginning after 4 a.m. when the low temperature is expected to be around 35 degrees. Rain is likely to continue to be a factor into the morning. But the afternoon should just be cloudy, with highs in the mid-40s, if the forecast holds up.

But to the north and west, the precipitation may be icier. In Westminster, forecasters are calling for rain, "possibly mixed with sleet, beconming all rain after 9 a.m." The ground, and the streets, are still too warm for any of it to stick, or glaze. But it may catch your attention as you head out for Grandma's.

All of this comes about as the high pressure, cooler temperatures and sunshine we're enjoying Wednesday morning move off to the east and a warm front approaches from the south. That will bring more moisture into the picture, and we can expect high clouds to begin appearing from the west late today.

As that moisture hits the colder air to the north and west of the urban corridor, it's going to begin raining. And as that rain falls early Thursday morning, evaporational cooling may get temperatures low enough to our north and west to turn rain to ice as it falls, forecasters said.

The clouds will stick around after the precipitation ends, making it a gray and damp sort of Thanksgiving. But temperatures won't fall much as evening arrives and more warm air arrives from the south. Friday's high will reach the mid-50s early as the next cold front approaches with more rain chances. The front will slip by during the day Friday, opening the door to some much colder air from the Arctic as the day goes by.

Overnight lows Friday into Saturday may drop below freezing, rebounding only into the mid-40s on Saturday and Sunday. Sunshine will make it a nice weekend for shopping. Or loafing.

(SUN PHOTO: Karl Merton Ferron, March, 2007)