January 17 12z NAM omega and negative EPV valid 1/18 12z
Notes:
Data from the same northern New Jersey to eastern Lake Ontario cross-section indicated that a very narrow layer of negative saturated geostrophic equivalent potential vorticity (EPV, indicated by the blue shading) was forecast to intersect the upward vertical motion across the western Catskill mountains. This indicated the potential for the ascent associated with the frontogenesis (shown in the previous slide) to narrow and intensify, which could result in enhanced snow banding.
Slide 20