Down here in Media Delaware County I am going to take these factors into mind here in Central Delaware County:
1. Temps above freezing overnight.
2. Warm ground temps.
3. elevation
4. rate dependent snows
My snowfall totals in Delaware County:
Media 2-4"
Ridley 1-3"
Newtown Square 3-6"
All broughs along the Delaware River 1-2"
Garnet Valley 3-5"
Radnor 3-6"
Havertown 2-4"
Springfield 2-4"
Broomall / Marple 2-4"
Chester 1-2"
Swarthmore 1-3"
Clifton Heights 1-3"
Upper Darby 1-3"
Drexel Hill 1-3"
Eastern Delaware County 1-2"
Think I covered it.
Relax Ralph it has not happened yet. I too STILL have my doubts. We shall see currently 42.3f dewpoint 37f so we aren't close to changeover yet, but I know not to look for this prior to 5 am here.
They all do Delaware County Coating to 3" honsetly though this is really tough but don't blame the lower totals with ground temps but dynamics can overcome and that is what this storm will be all about dynamics with heavy rates.
Yep this is also NOT one of those situations where snow ratios less liquid further north will help you. In order to get the heaviest snow you MUST BE in the heaviest corridor of moisture banding. This could be a rate dependent snow that can flip from snow to rain back to rain depending on rates so there is that variale too.
I think if I am forecasting for SE pa like here in Media Delaware County I would call for 3-5" or so.
I was 9 years old in that storm in 1983, but I think this is a wee bit different set up. This trend here is unprecidented, fun, unexpected but the temps???
NAM seems reasonable think it may be accounting for the cold air crashing and also elevation. I am very interested to see what the GFS says, but honestly it is time for short range dynamic models. Anymore shifts to the SE and region wide north and west of the Delaware River gets pasted. What is tricky in this situation you cannot salt the roads in the rain and this is CLEARLY a rain to snow event.
The rain snow line will be monitored like a hawk! The earlier the changeover the more snow you get I would think in this case.
Looking at the water vapor map pretty good push moving SE pretty quickly from Winnepeg through Minnesota heading for the Great Lakes. I wonder if this scoots our storm a bit further south and east.
Umm I am NOT ignoring the trend on the NAM clearly more south and a bit stronger!
That is from the NAM an undeniable switch to heavy snow just after 6 am in Delaware County.
The long range is evaporating for snow chances. I see the same old theme being played out a lack of cold high-pressure systems.
I dare say it may be time to pack up the season soon at least we got 9.6" this year in Media instead of the 1.7" we got this year so victory, I guess!
Rain to Snow early Tuesday Morning I am expecting speckles of white on the grass maybe?
Total snowfall in Media from this storm 0.4"
Souther maybe but end result not much different clearly temp issues. I think this may not be too far off from reality think you can shave a lot of that in south Jersey away though.