Further Development of a Statistical-Dynamical Ensemble for Tropical Cyclone Intensity Prediction

SPICE (Statistical Prediction of Intensity from a Consensus Ensemble) provides tropical cyclone intensity guidance by utilizing a combination of statistical ensembles generated from multiple dynamical models. SPICE is created using a combination of two statistical-dynamical models, the Logistic Growth Equation Model (LGEM) and the inland decay version of the Statistical Hurricane Intensity Prediction Scheme (SHIPS). These statistical-dynamical models are run three times each, once for each dynamical model that provides the necessary input data. The three dynamical models chosen to serve as input are the Global Forecast System (GFS), the Hurricane-Weather Research and Forecasting (HWRF) model, and the Geophysical Fluid Dynamics Laboratory (GFDL) hurricane model. The three forecasts of SHIPS are averaged to form an unweighted SHIPS consensus, and the three forecasts of LGEM are averaged to form an unweighted LGEM consensus. The two unweighted consensus forecasts are then combined into one weighted consensus, with the weights determined empirically from the 2008-2010 SHIPS and LGEM samples. These weights favored the SHIPS consensus in the early time periods, shifting to the LGEM consensus being weighted more heavily after about 36 hours.

SPICE has been run retrospectively since 2008 and in real-time demonstrations since 2011 as part of the Hurricane Forecast Improvement Project (HFIP). Results from SPICE will be presented, as well as versions of SPICE incorporating additional regional and global models.

DISCLAIMER: The views, opinions, and findings in this article are those of the authors and should not be construed as an official National Oceanic and Atmospheric Administration (NOAA) and/or U.S. Government position, policy, or decision.