January 17 12z NAM frontogenesis and omega valid 1/18 12zNotes:A NAM forecast cross-section of frontogenesis and vertical motion valid at 12z on the 18th (from northern New Jersey to central New York) indicated a layer of frontogenesis centered around 700 mb over the western Catskill mountains. An upward vertical motion maxima of around 5 microbars per second was associated with the frontogenesis.![]() Slide 19 |