Objective Evaluation for the High Resolution Hurricane Test Plan

Tropical cyclones are a serious concern for the nation, causing significant risk to life, property and economic vitality. The NOAA National Weather Service has a mission of issuing tropical cyclone forecasts and warnings, aimed at protecting life and property and enhancing the national economy. In the last 10 years, the errors in hurricane track forecasts have been reduced by about 50% through improved model guidance, enhanced observations, and forecaster expertise. However, little progress has been made during this period toward reducing forecasted intensity errors.

To address this shortcoming, NOAA established the Hurricane Forecast Improvement Project (HFIP) in 2007. HFIP is a 10-year plan to improve one to five day tropical cyclone forecasts, with a focus on rapid intensity change. Recent research suggests that prediction models with grid spacing less than 1 km in the inner core of the hurricane may provide a substantial improvement in intensity forecasts. The 2008-09 staging of the high resolution test aims at quantifying the impact of increased horizontal resolution in numerical models on hurricane intensity forecasts. The primary goal of this test is an evaluation of the effect of increasing horizontal resolution within a given model across a variety of storms with different intensity, location and structure. A secondary goal is to provide a data set that can be used to explore the potential value of a multi-model ensemble for improving hurricane forecasts.

The Developmental Testbed Center (DTC) and the HFIP Team hosted a workshop at the National Hurricane Center in Miami, FL, 11-12 March 2008. Experts on hurricanes, numerical modeling and model evaluation met for two days to discuss the strategy for this test. The test plan that was put together following this workshop reflects the consensus reached on the framework for this testing effort. Seven modeling groups expressed interest in participating in the testing effort at the time of the workshop. This presentation will briefly describe the basic elements of the test plan and then summarize the results of the objective evaluation performed by the DTC for the available model data.