Another winter storm, with the potential to dump heavy snow on southwestern Connecticut, is plowing toward the region, the National Weather Service warns this morning.

The snow -- which could add 6 to 12 inches to the blanket already on the ground -- is expected to start Tuesday night and continue through Wednesday afternoon, the NWS says in a Winter Storm Watch.

Today, in contrast, should be sunny, with a high temperature near 33 degrees. There will be a northwest wind between 9 and 18 mph.

Tonight should be mostly clear, with a low around 19.

Tomorrow starts out partly sunny, according to the NWS, with a high near 34. A north wind will be clocked between 3 and 7 mph.

Snow should start falling late Tuesday, mainly after 10 p.m. The snow is expected to be heavy at times, with initial accumulation of from 4 to 8 inches. The nighttime temperature will be in the mid-20s, with an east wind between 8 and 16 mph.

The snowfall will continue Wednesday, mostly before noon. The daytime high temperature will rise to the mid-30s, and a northwest wind will be between 18 and 21 mph. Wednesday night will be cloudy and blustery.

Thursday should be partly sunny, with a high near 29 degrees.