Examination of The Various FIM Model Configurations and Other NWP Guidance For An Historic High-impact Snowstorm In The Northeast U.S. In Late October.

Abstract

The FIM (Flow-following finite-volume Icosahedral Model) is a relatively new global model developed at the Earth Systems Research Laboratory (ESRL)/Global Systems Division (GSD) of NOAA. Key differences between the FIM and most other operational models include not only the icosahedral horizontal grid but also an adaptive isentropic-sigma hybrid vertical coordinate. Potential future roles for the FIM include becoming a part of the North American Ensemble Forecast System (NAEFS), along with the current members from the NCEP Global Forecast System (GFS) and the Meteorological Service of Canada Global Model, use as a global model for hurricane forecasting, and as a climate model. At GSD we have been running a number of different versions of the FIM, testing assimilation techniques, different horizontal grid resolutions, and other variations. In this talk we will give a brief update on the FIM, but the main focus will be an examination of FIM performance for a variety of relatively high-impact weather events over the past year. Comparison amongst the various versions of the FIM will detail how horizontal grid resolution, for example, affects the forecast. In addition, we will compare FIM forecasts with other operational models with an emphasis towards highlighting whether the FIM solutions provided additional useful diversity for the selected weather events.