WEATHER BLOG: More On The Snow

The high pressure system that is supplying us with our cold air will also provide plenty of sunshine during midday. This afternoon, some high, thin clouds will start to creep into the Northeast and mid-Atlantic states. A disturbance is currently bringing snow to parts of Iowa, northern Illinois and central Indiana. This is the feature we'll be watching very closely the next 24 hours. As the high pressure system located across the Northeast's interior begins to retreat early tonight, the fast-moving low pressure system is expected to swing across Kentucky and into the southern Appalachians. There will be an area of snow streaking eastward tonight, which will first reach areas south of the Mason-Dixon Line this evening before it spreads northward along the I-95 corridor after midnight.

There's still a concern that steadier and heavier snow will happen across central and southern Maryland, as well as in southern Delaware, Virginia and in the Greater Washington, D.C. before daybreak tomorrow.

We pointed out yesterday that since this snow will get started during the night, it will be able to stick to both paved and non-paved surfaces. Therefore, a measurable snow in cities like Baltimore or Washington may bring slick conditions before the morning rush starts tomorrow. But in Philadelphia and around the Greater New York City Metro Area, light snow probably won't become steady until after 6 a.m. - and then it should come to an end by 1 p.m.

Therefore, any accumulation should not lead to major travel disruptions, and it should average an inch or less. Locally higher amounts (2 or even 3 inches), should be confined to northern Delaware and central/South Jersey - the temperature profile in those places will be marginal for accumulating snow. It may be at or above 40 degrees for at least a while, so rain in that general area may mix with snow tomorrow, limiting the total accumulation.