Saturday, February 11, 2012

Round Two Comes Later On

Round two is a few hours away -- likely to start up around 4 PM or so across the suburbs as the instability trough dives through the region. In the interim, our "halftime show" will feature some light precipitation from time to time (spits of snizzle and drizzle) while the instability trough digs down from the northwest and the cold front associated with this system finally pushes through.

An inch or two of accumulation is likely across portions of the region -- best chances of this will be in Pennsylvania, South Jersey to the west of Route 206, and in Delaware.   These locations should be able to get in on the activity as it picks up later this afternoon and through the evening hours.  Snow showers will be steady at times and any we'll resume coating and accumulating on grassy and even paved surfaces as we work into the evening hours.

Temperatures will take a tumble as well this evening as the disturbance and cold front push through.  The NAM (below) suggests temperatures will drop below freezing between 7 and 9 PM in the city, a bit earlier than that to the west.  Like we stated earlier, the temperature drop won't be rapid but it will be three to four degrees per hour for a three hour or so period...that temperature drop will allow for non-treated surfaces to slicken up pretty quickly with the snow shower activity going on.  Additionally, winds will pick up later on as the front moves through, which means visibility levels will drop off in the snow shower activity.  Wind speeds will exceed 20 miles per hour sustained, gust to potentially 40 miles per hour in spots later tonight, resulting in wind chill levels that will drop into the single digits north of Philly, perhaps into the city as well.

Snow showers should taper off after 10 PM from the northwest, with a cold night and a cold Sunday setting up.

More:  Current Weather Page