And that is exactly what is going on in the weather regarding PA and NJ weather for tomorrow. A war of words over this question: Can snow accumulate during the day in April?
Simple answer: YES it can accumulate in April (See NY, CT, RI, MA Mon)!
Misleading Answer: No, due to the high sun angle.
Why is that misleading? Well, one question: how did the snow accumulate even on roads in NY, CT, RI and MA during the day this past Monday? The sun angle pretty high there too!
Look, the real truth about snow accumulation is that surface temperature is the key. If it’s 28 degrees in the middle of April, snow will accumulate. And if it’s 34 on Dec 21st, snow will struggle to accumulate. Not really the angle of the sun. It’s what the temperature is at ground level. Yes, the sun angle drives the seasonal change in temperatures, but to just say that snow cannot accumulate in April simply because of the sun angle is misleading. It’s really about the surface temperature.
Now about Saturday's snow (which I am not too excited about. Bring on the warm weather!):
- Strong upper level system (not really a clipper system either, but won’t argue), brings a strengthening system from Ohio east across PA and NJ.
- Upper level energy strengthens at the same time, passing just to our south or slightly overhead. This puts us in the ideal location for precipitation. Expect about .5” of rain/melted snow.
- Temperatures are the key here. I believe we will be around 33-34 in the valleys while it snows. The snow will pack and melt slowly as it falls.
- Snow starts around daybreak and ends by 4 pm.
- Accumulations on cold surfaces like grass: 3” valleys and 5” ridges.
- Roads could be slick early in spots, but by mid-morning they should be good.
What could go wrong?
- If temperatures are 2-3 degrees colder, then snow amounts may double for both valleys and ridges.
- If temperatures are 2 degrees warmer, we have “white rain” and no snow accumulation.
As you can see, it is a tricky forecast that could be very wrong. I gave you my best guess. I would not be surprised to see either extreme and I wish it were going to be sunny and 65 too. But we do not control the weather ... thankfully.