Conclusions

  • Model forecasts with this event were generally good. They were initially too far south, but trended in the right direction.

  • The Eta and GFS forecasts were fairly similar, however the Eta consistently forecast more QPF farther north. This may have been related to the fact that the Eta forecast more intense mid-level frontogenesis, and a stronger lower branch (southeasterly flow) to the resulting circulation.

  • In addition to model QPF, marginal banding signals and expected high snow to liquid ratios aided forecasters in producing high, accurate snowfall forecasts.

  • The new WRF model showed promise, producing excellent forecasts with this event. The new reflectivity product was particularly impressive.

  • The lower-resolution SREFs were not able to capture the bands of heavy snowfall on the northern edge of this storm, and therefore were of limited value.

  • Accurate prediction of the movement of the dry slot with this event were critical. Apparently, the track of the 700 mb low a bit farther north than model forecasts led to the dry slot pushing north all the way to the New York / Pa border. As is usually the case, heavy snow developed north of the dry slot.

  • This case was characterized by a narrow band of negative EPV collocated with relative humidities mainly in the 60 to 80 percent range at the edge of the dry slot over central to eastern NY. While snowfall totals in this case were rather high over our forecast area, extreme snowfall rates occurred farther east, where stronger frontogenesis combined with negative EPV and deep saturation.

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