WEATHER BLOG: Cloudy

The surface map has high pressure up off the coast south of Nova Scotia that has an extension that noses southwestward into the central Appalachians. Weak surface low pressure is near the coast of North Carolina and is a reflection of upper low pressure spinning across Virginia and North Carolina. Changes will be slow to unfold in the overall pattern over the next couple of days with a component of easterly flow across our area between the high offshore to the north and the lower pressures south along the coast. But the upper level energy will slowly progress northward, along with deeper moisture, as we head through Saturday into Monday.

The upper level low and a few separate embedded vort maxes rotating around the upper low can be seen bringing the pockets of rain and showers farther south of Dover, Del. to Washington, D.C. line Saturday morning. This wet weather will slide slowly northward bringing Baltimore to Philadelphia some wet weather Saturday, mainly in the afternoon in Philadelphia with a fringe spotty shower up into Allentown and perhaps New York City. This general slow progression will continue northward Saturday night,  Sunday and into Monday before lifting primarily to the north of Baltimore Monday with less impacts in Philadelphia Monday and still a few showers in New York City. The progression of the timing looks like that the wettest time period in Baltimore is Saturday afternoon and evening, with still a few showers and perhaps a thunderstorm around Sunday, then later Saturday and Sunday in Philadelphia for the most concentrated of the showers. Allentown will have the most numerous showers, which should be less than Philadelphia Sunday.