MGorse

Impressive storm in more ways than one.

Delaware County is not split like that.

Their perspective will change when it is snowing at 1-2 inches per hour and the temperature is 32-34 degrees.

That is at 13z. Still snowing after that.

The main forecast updates are issued around 4 AM/PM.

The HREF is looked at but I would not say we rely heavily on it.

This is insane! I would literally be pulling my hair out if working today. Did mention over the weekend at work that this storm could be a surprise but was not sure where.

Because given the uncertainty the Winter Storm Watch covers a bit larger area.

Yup, I missed that as well.

This storm setup has that look though of an area of heavy banding which would be all snow as the column cools. We shall see. I just want to know, how much snow for Philly?

Not saying the GFS is right for the later Monday and Tuesday storm, however it shows some strong lift centered within the snow growth zone with high relative humidity especially from about I-78 northward when it shows all snow. Surface temperatures fall to near freezing so it would be a wetter snow. It looks to be a quick moving storm, but something to watch as potentially stronger dynamics come into play.

Yeah I noticed that a couple of weeks ago. I am not sure when they returned to KYW.

Looks like the 12z GFS did not go way north.

You mean those maps are not a lock?!

Overall a period of deeper lift within the dendritic snow growth zone (boosting the fluff factor), thermal column cooling once the snow started (initially surface dew points were in the low to mid teens), and going with higher snow to liquid ratios (about 12:1 to 17:1). Looks like we were on the high side particularly for some areas near and north of I-78, and on the low side across parts of northeast MD into southern DE. Overall to me this was not a classic norlun trough as there was no real heavier focused band of snow aligned parallel to the surface/inverted trough. There was synoptic lift that in conjunction with the surface trough resulted in a wider area of 4-6 inches of snow. I hope everyone enjoyed the snow. I will enjoy my weekend off as it has been a long week.

Those warnings were issued where the latest NWS forecast snowfall totals meet criteria, not the models.

LOL. Nope, not my decision.

Looks like she was showing their 'Fox Model' which is probably not their actual current forecast totals, for what its worth.

The NWS currently does not have 6-8 inches in the forecast.

That will be reviewed again during today, but yes definitely looks like a good setup for a period of blowing and drifting snow.

What is a 'blowing snow statement'?

Amounts are no higher than 4-5 inches currently in the forecast (map plots as 4-6 inches).

True but it can end up crossing advisory versus warning criteria. And the WSW product has 2-4 inches but the graphic has an area of 4-6 inches.

A note regarding the NWS total snowfall graphic. If the forecast amounts just cross over a whole number it bumps to the next range. For example, an area of 4.1 to 4.5 inches will be plotted as 4-6 inches. In this case, the forecast actually is not for 5-6 inches.

That Philadelphia in the PNS is not PHL Airport.