Summary of the more detailed model diagnostics from the 28/00 UTC model runs.

  • The NAM was forecasting more mid-level frontogenesis, farther west than the GFS.

  • The NAM was forecasting more divergence above the frontogenesis over central New York, resulting in a stronger convergence / divergence couplet and more upward vertical motion over central New York.

  • The NAM was forecasting a better banding signature over central NY than the GFS, with a pronounced tongue of negative EPV become collocated with the upward branch of the frontogenetical circulation in that area.

  • Isentropic analysis indicated that the NAM was forecasting stronger positive pressure advection than the GFS over central New York (more isentropic up-glide).

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