Winter Weather Forecast

Last Updated

Forecast Update Fri 11:30 AM
This mornings NAM data just available shows a QPF of 0.15 inches water. This morning’s GFS has a QPF of 0.11 inches water.

Based on the average, we’re back to 1, possibly 2 inches of snow, starting about 9-11 PM and ending about daybreak on Sunday.  Considerably less the further north one is from Philadelphia. 

There’s been tremendous consistency and continuity with the models and the storm track. I’ll update tonight with my usual Weekend Weather Forecast about 10:45 PM.

Forecast Update Fri 10 AM
This mornings NAM data just available shows a QPF of 0.15 inches water. The GFS data is not yet available this morning, but last night’s 06 UTC (1AM EST) run showed a bit higher- 0.22 inches water for Philadelphia.

The forecast remains on track for 2 inches, possibly 3, in Philadelphia with lesser amounts to the north. Light snow starts early evening Saturday and ends during the morning hours on Sunday.

There’s been tremendous consistency and continuity with the models and the storm track.

I’ll update tonight with my usual Weekend Weather Forecast about 10:45 PM.

Forecast Update Thurs 12 PM
This morning’s models (NAM, GFS, FV3-GFS) are in remarkable agreement with a forecast of light snow starting early Saturday evening and ending sometime during the day on Sunday. Most of Sunday should be snow-free with the exception of light flurries.

The total QPF is about 0.18 inches water, which translates into about 2-3 inches of snow at these temperatures.

Today’s GFS is down-playing intensification with throw-back snow later on Sunday.

There is increasing agreement among the models that the low pressure system will track to our south. We’ll be on the northern fringe of the precipitation shield.

Over-running moisture ahead of the low cause light snow to fall late Saturday afternoon or Saturday evening.  About 1 inch or so is expected in the general Philadelphia area by Sunday morning.  (Total QPF water equivalent is 0.10 inches)  The NAM and GFS are in agreement, as is the FV3-GFS.

Sunday will be cold but little if any snow is expected during the daytime hours. Any snow will fall to our south in Delaware.

The GFS has some intensification and development of the low as it reaches the coast Sunday evening.  It shows some throwback moisture, allowing some additional snow Sunday night. An additional 1 inch of snow is possible Sunday night.

GFS forecast
GFS forecast Animation for Sunday

As everyone who reads my blog knows, we really can’t make an accurate call on QPF and snowfall amounts until 12-18 hours before the event.  Stay tuned.