We haven’t had a good fluff bomb in a while and it looks like Tuesday night’s storm will deliver the goods. The atmosphere will be very cold during tomorrow’s storm. More importantly, temperatures at cloud level where snow crystals will form will be around -15ºC which maximizes snow growth efficiency and favors dendrites.
Here’s a time-height cross section for New Haven with omega (negative values indicate upward motion) outlined in red and >90% RH between -12C and -18C outlined in yellow. We call the saturated layer between -12C and -18C the snow growth zone of dendritic growth zone.
In addition the snow growth zone is quite deep – extending from near the surface up to 600mb! A sneezing seagull could produce a dendrite in a setup like that. The GFS also shows impressive snow growth. I’m bullish on this one.
As I mentioned yesterday the band of snow across the I-95 corridor will be force by a strong frontogenetical circulation. On the warm side of the circulation air rises and, in this case, produces snow. You can see the frontogenesis on the GFS for 00z Wednesday.
That’s a solid signature. Additionally, the European model which had been fairly stingy with this storm (keeping best lift and moisture offshore) has arrived at the party. Late is better than never. 4″ of snow is likely across virtually all of Connecticut with odds of >8″ of snow about 50/50 for the shoreline.