Application of the NMME for the Intraseasonal Prediction of Tropical Cyclones over the Atlantic and North Pacific Basins

“This proposal is directed to the NOAA OAR CPO FY2015 and targets the Competition of MAPP – North American Multi-Model Ensemble (NMME) system evaluation and application, Area B: Exploration of new application of NMME system predictions. The objective of this project is to develop a suite of dynamical–statistical forecast models for intraseasonal forecasts of Atlantic and North Pacific basin tropical cyclone (TC) activities using the data from the NMME-Phase 2 system.

Introduction to the problem: Tropical cyclones have significant social and economic impacts. Their activities exhibit large intraseasonal variability, which is modulated by the Madden–Julian oscillation (MJO). A below-normal hurricane season may have certain periods with active TC activity, and vice versa. Therefore, issuing skillful intraseasonal forecasts of Atlantic and PacificTC activity in a timely manner would be important and beneficial for the TC-affected areas.

Rationale: With the development of the NMME-Phase 2 system, data at higher temporal resolution (daily and 6 hourly) are becoming available. An evaluation of CFSv2, one of the NMME models, indicates that the MJO is better represented with a higher prediction skill in CFSv2 than in CFSv1. Based on the performance of the NMME in the experimental seasonal climate prediction, it is reasonable to expect that the intraseasonal forecast skill of the MJO will be further improved with the NMME-Phase 2 system. The multi-year retrospective forecasts in the NMME-Phase 2 system offer a unique opportunity to develop and test the dynamical–statistical models for the forecasts of 30-day mean Atlantic and North Pacific TC activities.

Brief summary of the work to be completed:
(1) To establish the empirical relationships between the observed 30-day mean tropical cyclone activity and the NMME-Phase 2 system predicted ocean/atmosphere conditions for the same 30-day moving window throughout the entire hurricane season for the tropical North Atlantic, eastern and western tropical North Pacific regions, respectively, based on the 1982–2010 data, and identify potential predictors for the intraseasonal TC forecast;
(2) To apply a hybrid dynamical–statistical model for the intraseasonal tropical cyclone forecast with the multiple linear regression method and cross-validate the forecasting system over the 1982–2010 period using the NMME-Phase 2 system hindcast suites; and
(3) To test the model for real-time intraseasonal forecasts for the 2016 hurricane season and implement the model into operations at NCEP/CPC. Relevance to the Competition: This project will explore new applications of the NMME-Phase 2 system, test and evaluate new prediction products for intraseasonal tropical cyclone activity. Therefore, it is highly relevant to the Competition of MAPP, Area B. The project will also support the NCEP/CPC Global Tropics Hazards and Benefits Outlooks. The proposed work will help accomplish the NOAA’s long-term climate goal by improving one of the core capabilities, namely, predictions and projections, and addressing the societal challenge of the changes in high-impact extremes of weather and climate, as described in the NOAA’s Next-Generation Strategic Plan.”