I just got an email from my sister:
Actually, denser air creates high pressure. High pressure sinks. Clouds can’t form.
I’m not sure how she and the family are living in Wisconsin this winter. It’s the kind of weather that tries men’s souls. Lots and lots and lots of snow. There’s enough that some towns have run out of money and stopped (or sharply curtailed) plowing and treating roads!
We’ve had very little snow in my part of Connecticut (there is a huge variability within the state this year). I can’t tell you how relieved I am, especially since my friend Bob, the meteorology professor, says Northern Hemisphere snow cover is way above average!
Earlier today we got what’s in the attached photo – graupel. It’s not unknown, but it’s not an everyday occurence either.
Sometimes distinguished by shape into conical, hexagonal, and lump (irregular) graupel.
That definition, from the American Meteorological Society, would be much shorter if it just said, “snow that looks like Styrofoam.”
It snowed (actually, graupelled) for a few minutes this afternoon while the wind howled. This small accumulation was gone within five minutes. Today, it’s weather my sister is jealous of.