1. Objective and Automated Assessment of Operational Global Forecast Model Predictions of Tropical Cyclone Formation Patrick A. Harr Naval Postgraduate School Monterey, CA Acknowledgment: NOAA, Joint Hurricane Testbed Project

2. Synthesize model representations of 850 hPa vorticity centers Data are gathered on all tropical vortices Before formation of tropical cyclone Target circulations may be waves Not intended to replace operational trackers associated with existing tropical cyclones Not applicable to regional models that are only run when a tropical cyclone exists OBJECTIVES

3. Summarize a large number of parameters associated with each center throughout its life cycle. Two levels of interface (1) Interface during operations to examine current vortices via NMAP2 allow hurricane specialists to monitor: - vortices in the current analysis and their forecasts -vortices forecast to form in the current modelrun (2) Interface to examine general summaries of forecast performance with respect to tropical vortices that may become a tropical cyclone conditioned on season, location, intensity, etc. via web-interface with the database (MySQL/PHP) Identification of false alarms - forecast to become a tropical cyclone but does not verify -declaration of a model tropical cyclone based on several criteria (warm core, etc.) OBJECTIVES (continued)

4. Catalog in a dynamic database –Database designed to answer user-generated queries for statistical summaries associated with model performance based on Time period area Forecast parameter (850 hPa vorticity, SLP, rainfall, warm core, etc). Parameter thresholds (e.g., vorticity above/below a specified value) Model OBJECTIVES (continued) Identify factors that discriminate between likely model traits with respect to tropical cyclone formation. [ Objective, feature based, dynamic]

5. Forecast Model Analyses and Forecast Fields Tropical Cyclone Vortex Tracking Program(TCVTP) Tropical Cyclone Vortex Tracking Program(TCVTP) Forecast Data Base Circulations forecast to occur Forecast Data Base Circulations forecast to occur Analyzed Data Base Current tropical circulations Analyzed Data Base Current tropical circulations Current circulation summaries/ verifications Final Circulation Catalog summaries/verifications conditioned on Season, location, intensity,etc. Final Circulation Catalog summaries/verifications conditioned on Season, location, intensity,etc. Catalog of False Alarms Catalog of False Alarms Overall System Design GFS NOGAPS UKMET Interface during Operations via NMAP2 Database Interface

6. With respect to the each tracked vortex, the following parameters are cataloged: 850  maximum value SLP average, minimum value 500-850 hPa wind shear 200-850 hPa wind shear 1000-200 height thickness 500 hPa vertical motion 700-500 hPa moisture model-derived accumulated precipitation temperature difference between area inside ellipse and outside ellipse at 500 hPa

7. Interface to monitor forecasts of current vortices and vortices forecast to form Interface is provided via NMAP2 Choose Data Source (model) Choose Data Window (time)

8. Choose from track list that identifies vortices in the current analysis Display 850 hPa vorticity and track for vortex of interest

9. Choose from track list that identifies vortices forecast to form in the current model run Vortices in the current analysis and their forecasts (red) Vortices forecast to form and their forecast tracks labeled by the time at which they appear in the forecast sequence (green)

10. Interface 2 Summaries of overall model traits with respect to tropical vortices Use of database design to allow user-defined queries for the catalog of analyzed and forecast parameters with respect to tropical vortices. Examine vortices within specific model runs Examine general summaries of model performance

11. Choose region, time, and model Choose to display parameters for a vortex defined in a list of current vortices Choose from a list of previous model runs Choose from a list of previous vortices

12. Overall model performance: Can be defined via user specification of important operational factors (i.e., location, intensity, time, parameter) Define conditions on which to base statistical analysis of model traits Choose the parameter to summarize Choose summary format: Table, Plot of absolute error and bias error, Box and whisker plot

13. Output available in tabular and graphical formats. Output available in various statistical representations to identify likely sources of forecast errors.

14. Objectively identify and track analyzed and forecast vorticity centers in operational global forecast models Summarize a comprehensive set of physical parameters associated with analyzed and forecast vortices. Catalog parameters in a dynamic data base Provide daily and other summaries of model forecast performance associated with developing and non-developing tropical vortices. Use summaries to discriminate between potentially accurate/inaccurate forecasts of TC formation. Summary