Go figure. Winter starts at 1:10 EST early tomorrow morning, and the weather service is predicting a Sunday high near 60 degrees for Baltimore, with a thunderstorms possible after 1 p.m. Sounds like Christmas in South Carolina. The record for a Dec. 23 in Baltimore is 69 degrees, in 1990.

Here's the deal: There's a big high pressure system over eastern Quebec at the moment. Highs spin clockwise, so that's bringing damp, cool surface air in off the Atlantic and up against the Appalachian slopes. Warmer air is moving in aloft from the west, and together they're contributing to our cool, gray, dreary weather. Showers are possible tonight, and likely tomorrow.

There's also a storm brewing in the Southwest. That's a low-pressure center, and they circulate counter-clockwise. They're expecting this one to intensify and track north and east along a fast-moving jet stream. It's likely to reach the Midwest by Sunday morning. That puts folks in the western Great Lakes in the path of some snow, but we get a strengthening flow of winds and mild, wet air from the south Sunday afternoon.

The air mass may be warm enough, and unstable enough to spark thunderstorms Sunday afternoon east of the I-95 corridor as the next cold front approaches from the west. That will clear the skies for Monday, and drop our highs back into the 40s - about right for this time of year.

Christmas in Baltimore looks at least partly sunny, with a high about 46 degrees.

The next chance for precipitation comes late Wednesday into Thursday as another "potent" storm system moves in. This one will be likely be rainy, too. No snow. Sorry.

If this weather is too depressing, click over to the new Science Matters blog and explore some of the weirdest and most interesting science news our reporters have discovered in recent days.