FV3 TC Forecasts

From 2016-2018, I worked at NOAA's Geophysical Fluid Dynamics Laboratory (GFDL). The FV3 dynamical core (think of it as the "engine" of a weather or climate model) was developed at GFDL, and is now the core of the GFS, the main U.S. Weather Model.

https://www.weather.gov/news/fv3

FV3-powered models are used for a wide range of applications at GFDL, from severe thunderstorms (https://hwt.nssl.noaa.gov/Spring_2017/HWT_SFE_2017_Prelim_Findings_Final.pdf) to seasonal and climate prediction. My research at GFDL focused on evaluation of short and medium-range hurricane forecasts using high-resolution (2-3 km resolution versions of the model). Some of the key findings are discussed below.

Hurricane forecasts are often evaluated by comparison of the track and wind speed from the model forecast with the observed track and intensity. One of my research goals is to evaluate model forecasts of hurricane structure (such as storm size and vertical depth), to make sure the track/intensity forecasts are right for the right reasons. In a paper in press in Weather and Forecasting, we look at fvGFS (FV3 with GFS model physics) forecasts of several Atlantic hurricanes and compare with radar data from NOAA HRD flights. An example from Hurricane Earl (comparing horizontal and vertical wind structure of the model and observations) is shown to the right.

The 2017 Atlantic Hurricane season featured many strong, rapidly-intensifying TCs, including the high-impact storms Harvey, Irma, and Maria. High-resolution fvGFS forecasts for these storms are being analyzed, and results are in another paper in preparation for Weather and Forecasting. The videos to the left show a simulated radar forecast for Hurricane Irma, as well as the observed radar (edited with permission from Brian McNoldy). The model correctly predicted a lot of the structural evolution as the storm moved over Florida.

This is an animation of all the 12-hour forecasts of fvGFS simulated satellite imagery during the 2017 Atlantic hurricane season . The cases stretched from August through October.

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