Tropical Cyclones

Providing Meaningful Information About the Quality of Tropical Cyclone Forecasts

In 2009, RAL's Joint Numerical Testbed formed a new entity called the Tropical Cyclone Modeling Team (TCMT). The focus of this team is testing and evaluation (T&E) of experimental models for tropical cyclone forecasting. The current primary sponsor of work in the TCMT is NOAA's Hurricane Forecast Improvement Project (HFIP). HFIP is a 10–yr NOAA effort to accelerate improvements in 1 to 5 day forecasts for hurricane track, intensity, & storm surge & to reduce forecast uncertainty, with an emphasis on rapid intensity change.

The TCMT is a joint effort within the JNT to bring tropical cyclone modeling research to operations (R20). New methods in the areas of model physics, numerical computations, data assimilation, and atmospheric/oceanic coupling are tested and evaluated within the TCMT. To provide an efficient means to bring tropical cyclone model research to operations, the TCMT has been organized into Developmental Testbed Center (DTC) and non–DTC activities. The DTC activities primarily focus on designing carefully controlled tests of promising new features or techniques in the operational tropical cyclone models. The DTC also generates the required retrospective forecasts for T&E of operational tropical cyclone models. The non–DTC activities include providing guidance on the formulation of testing plans for experimental tropical cyclone models. Other non–DTC efforts also include the collection of product output from participating experimental modeling groups to perform independent T&E. Both the DTC and non–DTC efforts include performing objective evaluation with statistical tools & techniques that determine whether differences in performance are statistically significant.

Tropical Cyclone Monty Cloud top height measurements for Monty before the storm made landfall over the remote Pilbara region of Western Australia.
Tropical Cyclone Monty: Cloud top height measurements for Monty before the storm made landfall over the remote Pilbara region of Western Australia.

Currently, the TCMT DTC efforts focus is the WRF for Hurricane (HWRF) operational modeling system. Specifically, the TCMT DTC emphasis has been on developing and maintaining a hurricane T&E infrastructure for HWRF; performing HWRF tests to assure integrity of code & the evaluation of new developments for potential operational implementation; establishing a diagnostics effort to provide more informative feedback to model developers about model deficiencies; and the development, implementation, and sharing of tools for TC forecast evaluation.

The current non–DTC efforts focus leading the annual planning and coordination of the annual HFIP demonstration and retrospective evaluations; performing independent evaluations of the annual demonstration and retrospective studies (including global, regional, ensemble forecasts); performing in–depth model verification analyses of experimental tropical cyclone models for both retrospective and demonstration exercises; and providing a data service for HFIP community to facilitate further investigation of deficiencies in both operational & experimental models.


Kathryn Newman

Associate Scientist IV