Saturday 5PM Update: The low level cloud layer didn’t clear as I had expected. We remained socked into cloudy and damp all day. Sunday still looks cloudy and damp in PHL with a chance of light scattered showers, but the real rain arrives late afternoon.

A return to colder winter temperatures will occur this week in the Thursday-Friday timeframe.  The first few days of February look to be stormy at this time (although long-range forecasts haven’t been too good this year).

The warm front that moved through on Friday, has moved north and a southwesterly flow of mild air will move in for Saturday and Sunday.

Saturday will be dry and partly to mostly cloudy, but we can’t rule out some sun breaking through during the day, especially the afternoon.  High temp 55.

Sunday will continue mild, but an approaching large storm system will bring an increasingly easterly wind and clouds and during the day  and rain by nightfall. Right now, the GFS has most of the daytime hours rain-free.  High temp 56.

Already advertised, from Sunday night through Monday, expect a stormy period with high winds.  Right now, the GFS is predicting over 3 inches of rain!

10PM Update:  Latest NAM shows QPF values back up to 0.15 inches water.   The atmosphere warms a bit in the upper levels towards evening.  Here are the latest changes:  Light snow starts in the afternoon, mixes with sleet and possibly some freezing rain after 6pm and ends during the evening.  Accumulations less than an inch. Temperatures fall below freezing later Saturday night.

Today’s NAM has really backed off from the higher QPF values showing yesterday and this afternoon’s 1 PM model run (18z) has the QPF down to 0.06 inches water.  This falls into the category of a dusting or coating and at this low QPF level, this sometimes can translate into a complete zero.   The GFS has been in a similar range of QPF values.

The NAM has any precipitation occurring during the afternoon and early evening.

So this “snow event” (to use the TV people’s jargon) is looking like it’s not worth talking about.

The next data (NAM) becomes available after 9 PM and the NAM FOUS (Forecast OUtput Statistics)  about 9:40.   I’ll update only if there’s a significant change.

Saturday looks to be cold and cloudy with some light snow coating possible, per the discussion above, in the afternoon.  Light snow , sleet and freezing rain into the evening.  Highs about 32-33.

Sunday will be mostly sunny and milder.  Highs about 45.

The roller coaster of this season’s temperatures continues as the current dip in the jet stream relaxes and milder temperatures return for Sunday.

For Saturday, expect breezy conditions and slightly above average temperatures .  Sunny skies in the morning become obscured by mid level clouds in the late afternoon. Highs near 45.  (Average is 40.)

A weak front passes through New Year’s Eve.

Sunday is milder and sunny with highs near 50. Clouds move in Sunday night with showers on Monday.

A broad upper air trough with some very cold air establishes itself midweek with a return of cold weather here. The position and broadness of the upper air trough keeps the deep cold away from our area. It also keeps snow out of the forecast.