East Village Snow by AllWaysNY on Flickr

A complicated pair of weather disturbances are bringing a wintry mix to New York today. This morning a short wave trough, think of this as a kink in the jet stream, has brought instability to the atmosphere, which has caused the early morning snow to fall. The short wave will give way later today to a developing coastal storm, which will bring more snow and probably freezing rain and sleet. As a result the National Weather Service has issued a Winter Storm Warning, which is in effect until late tonight.

An additional 2-5 inches of snow is expected to fall across the city by this evening, but that's not why there's a storm warning. The coastal storm that will sock the city later today has a wedge of warm air running ahead of it. The wedge is above the ground and deep enough to melt much of the falling snow. The high today will be around 32 degrees. Cold rain falling on frozen ground adds up to freezing rain. Sidewalks and roads are likely to become slick this afternoon and the evening commute promises to be just as bad as this morning's.

The snow and freezing rain will taper off by tomorrow morning. Saturday will be a bit breezy, and the high will be in the mid-30s. Warmer and sunny on Sunday, with a high around 40. The next chance of a storm will be Tuesday.