Box AFD:
Heavy snow...
As mentioned above very cold/dry airmass over the region this evening will set the stage for an impressive front end thump of
heavy snow Monday afternoon and evening. Very strong easterly jet at 850 mb of 5 standard deviations will provide an Atlantic
fire hose of moisture to overrun the cold/dry airmass currently over the region. This strong forcing for ascent will be enhanced
by mid level instability Monday afternoon and evening as dry slot approaches. This entrainment of mid level dry air will
steepen mid level lapse rates and result in 1-2" hourly snowfall rates Mon afternoon and evening. HREF supports this with high
probs of 1-2" hourly rates. Even the HREF hourly mean is 1.5-2.0 inches. That combined with instability aloft, would not be
surprised if 3+ inch hourly rates for a time in the strongest snow bands, along with a low risk of TSSN! Nevertheless, travel
will be extremely difficult Monday afternoon and evening given these hourly snowfall rates. Given the evaporative cooling
potential initially, followed the colder guidance here. Although given low level temps are marginal across Eastern CT/RI/MA,
followed the lower SLR from the NBM which are less than 10-1. Although this may be offset early on as snow growth is very
favorable 18z-00z. Thus heavy wet snow across this region will increase the risk for snow loading issues/tree damage and power
outages.