2/27/12 Mild then snow for mid week.

A ridge of high pressure will move over New England and allow a southwest flow of air to boost temperatures to near 50 today for much of the Boston area.

Snow has an impact on temperatures. Where there is snow, the sun's energy must first go to melt the snow and ice. Then go to warming. Where there is no snow, the ground can warm much easier. Since our air will be coming in from the south today, where there is no snow, the sun will heat the land and allow temperatures to warm.

A weak area of low pressure will swing through this evening, bringing some clouds over night and bring temperatures down for the day on Tuesday.

As for the approaching storm for Wednesday afternoon into Thursday.  A potent snow storm is likely over parts of New England. The details on exact amounts of snow and locations of snowfall are not fully known. 

However for the Boston area, it appears that enough warm air will work in to allow for a mix of rain and sleet for Wednesday and Wednesday night.

As the low tracks east on Thursday a brief burst of snow is possible. Heavy snow could fall West of Worcester.