Proposal for a GIFS Forecast Demonstration Project

Proposal for a GIFS Forecast Demonstration Project

1. Project Summary

Forecast Demonstration Projects (FDPs) of the World Weather Research Programme have been instrumental in introducing research advances into the operational practices of Members of the WMO. The Global Interactive Forecast System Forecast DemonstrationProject (GIFS-FDP) is designed to transition THORPEX research and development, aimed at accelerating improvements in the skill and utility of 1-14 day high impact weather forecasts, into the operational community. Based on recent scientific and technological achievements, GIFS-FDP will develop new methods for the generation of advance probabilistic warnings for high impact weather events such as those associated with tropical cyclones and heavy precipitation. The new products will be designed, tested, and evaluated in quasi-operational setting such as the Severe Weather Forecast Demonstration Projects developed by the Commission for Basic Systems (CBS) of WMO.After thorough testing and evaluation, the scientific and technological procedures used for the generation of the new probabilistic products will be made available for use by the operational community, along with assistance in user training activities.

As a transition activity, GIFS-FDP will interact closely both with the research program of THORPEX and WWRP and also with operational weather forecasting activities such as the SWFDP, coordinated by CBS. The advantage of utilizing the SWFDP framework is that these research advances will be transitioned to operational practice of a large number of nations including developing and least developed nations. For example, the Southern Africa SWFDP effort began with five and has now expanded to sixteen African nations. GIFS-FDP, however, will significantly expand the scope of current SWFDP activities, including procedures for the statistical bias correction, downscaling, and potential combination of information from ensembles generated at a larger number of NWP centres. This document sets out the overall framework of the GIFS-FDP; regional subproject plans will be developed so that implementation of GIFS addresses the specific needs of each region in a “bottom-up” manner. Given its scope and ambitious goals, GIFS-FDP will also interface with other RDPs and FDPs (which we collectively refer to as pilot projects) to promote the advancement and more efficient operational use of NWP forecast information across a number of geographical and application areas.

2. Background and Motivation

INTRODUCTION

THORPEX is a ten-year long international research programme to accelerate improvements in the accuracy and utility of probabilistic predictions of high-impact weather on the one-day to two-week time-scale. THORPEX forms a major part of the WMO World Weather Research Programme (WWRP) and is a key research component of the WMO Natural Disaster Reduction and Mitigation Programme. The THORPEX implementation plan envisages the establishment of a future Global Interactive Forecast System (GIFS), to realise benefits of the THORPEX research programme by developing improvements to operational forecasting systems.

The objective of the GIFS is the production of internationally coordinated, ensemble-basedprobabilistic advance warnings and forecasts for high impact weather events to mitigate loss of life and property, and to contribute to the welfare of all World Meteorological Organization (WMO) nations, with a particular emphasis on least developed and developing countries. It is expected that the international coordination of the design, future development, and operation of global observing, data assimilation, numerical modelling, and user application techniques for high impact weather forecasting will yield significant improvements in the availability and quality of services, leading to a range of socio-economic benefits, including saving property and lives. GIFS will be developed through the volunteer contributions of national, regional, and international organizations, requiring significant investment from National Meteorological and Hydrological Services (NMHSs) and other organizations.

TIGGE and GIFS

The objectives of GIFS can be achieved only with a carefully planned, multi-year effort that started with the establishment of the THORPEX research programme. GIFS development fits into the following framework:

• TIGGE (2005 onwards). TIGGE (THORPEX Interactive Grand Global Ensemble) is an international data archive where numerical ensemble forecast providers share their data to advance scientific research related to improving high impact weather forecasting. TIGGE data are made available for research purposes with a time delay at three volunteer archive centers via site specific web interfaces (see thorpex/ ).
• GIFS Development(2008-2012). Building on the TIGGE data set, this initial phase of GIFS entails developing real time access to basic ensemble forecast data and creating an infrastructure for the generation of derived products and the provision of other related services. This phase began with the real-time exchange of tropical cyclone track information between a majority of the TIGGE data providers.
• GIFSImplementation (2012 onwards). The implementation phase of GIFS will enable the real time generation of products and services. This will be followed by further enhancements, leading to the formation of an “End-to-End” GIFS forecast system.

The development and generation of GIFS prototype products will require and include:

• Real time access to ensemble forecast data. This includes both an agreement on data policy to facilitate the necessary real time data exchange and the development of techniques to transfer data required to generate GIFS products.
• Statistical procedures to: bias correct individual ensemble members, combine information from all ensemble members and downscale calibrated ensemble forecasts
• Product design, in conjunction with user groups
• Product generation, using a distributed approach
• Testing, evaluation (including feedback from forecasters) and objective verification.
• Training potential users in the use of novel forecast products

GIFS-FDP

To facilitate the GIFS development phase, it is proposed to establish a GIFS Forecast Demonstration Project (GIFS-FDP), to develop products to meet the needs and requirements of the operational weather forecast community and evaluate the benefit of those products in an operational context. GIFS-FDP is a framework for the demonstration of GIFS products for particular types of high-impact weather events for selected regions. Subproject plans will be developed in order to address the specific needs and priorities of users in the selected regions.For the testing of the new products and their introduction to forecasters participating in the project, GIFS-FDP will build on the experience accumulated by the WMO Severe Weather Forecast Demonstration Project (SWFDP). The Southern Africa SWFDP sub-project is a good example of the successful delivery and use of operational products to support forecasts of high-impact weather for a specific region.

It is recognized that the motivation to commit the necessary volunteer resources to ensure a successful GIFS implementation will depend on demonstration of improvements to forecasting of high impact weather events that result from TIGGE research. It has also been recognized that verification efforts are needed as an integral part of any forecast demonstration project to document its benefits. Thus user-oriented verification activities will be included as part of all GIFS FDP activities.

GIFS-FDP activities build on the scientific achievements of the THORPEX Working Groups and broader THORPEX research community, including ongoing TIGGE-related and other research and technical achievements. The GIFS-FDP will seek and support funding initiatives related to the scientific and technical development of GIFS. Leveraging related efforts with other pilot projects will also promote the development of GIFS.To streamline its product development and delivery mechanism, GIFS-FDP activities will be aligned, wherever possible, with the ongoing or future SWFDP regional sub-projects, utilizing the same global-regional-national cascade paradigm to disseminate to, and to build capacity in the use of GIFS prototype products by forecasters at national centres in the relevant regions, and onward to users outside of the NMHSs. Thus, prototype and promising GIFS products will be developed to supplement or supersede the established forecast products already being disseminated via the regional SWFDP demonstrations. GIFS products will be developed in conjunction with specialised regional and national centres to ensure that they address regional priorities for improving forecasts of severe and high-impact weather.

3.FDP proposal

GOALS

The objective of GIFS-FDP is to develop and test prototypes for various high impact events. As a demonstration project, GIFS-FDP will provide an environment for the evaluation of prototype products for a limited time period. Prototypes will be selected based on scientific advances particularly GIFS-TIGGE based research and potential achieved by interest groups collaborating with the THORPEX and WWRP Research Working Groups, and opportunities presented by SWFDP and other user activities and interest. As discussed below, it is expected that the development activities will start with tropical cyclones, then move on to high impact precipitation, with other prototype products, resources permitted, to follow later. For each of these prototypes, initial GIFS-FDP development activities are expected to be completed within approximately 3 years, depending on available resources. Prototype development work will culminate in the 3rd year in real time testing and evaluation by operational users; products will only be introduced once a particular SWFDP regional subproject has matured in its demonstration framework. Depending on the evaluation results, successful prototypes will be transitioned into operations, allowing GIFS-FDP to shift its focus to new prototype development. Careful coordination during the development phase with operational centers and CBS is critical for the successful transition of GIFS prototypes into operations

Compared with the products available currently in the existing SWFDP programme, GIFS-FDP will introduce the following enhancements:

1)Scientifically driven development of new types of products to highlight forecasts ofsevere weather;

2)Products based on multi-model, rather than single-model, ensembles;

3)Statistically bias corrected and downscaled information as opposed to direct output from numerical ensemble forecasts

4)Longer range outlooks including week-2 forecasts (as opposed to current guidance limited to 3-5 days range) for long term planning and mitigation efforts related to possible future high-impactweather events.

GIFS-FDP PRODUCTS

It is proposed that GIFS-FDP focus initially on forecasting:

• Tropical Cyclones, and
• Heavy Precipitation.

Interest groups will be formed to develop, test, evaluate and eventually implement products for these two themes. The tropical cyclone group will extend the work done to exchange tropical cyclone forecasts during T-PARC, and develop products based on the Cyclone XML data. Concurrent with this, TC track forecasts from the accumulated data in the CXML TIGGE database will be verified against Best Track data. The tropical cyclone research and forecast community is planning to initiate a NW Pacific tropical cyclone demonstration project in conjunction with WMO’s Shanghai Multi-hazard Early Warning System Project in 2010. The project will likely include those nations in the NW Pacific area with a need for improving TC forecasts. In the planning for this effort, forecasters noted that the CXML exchange data currently contains track information only. From current forecaster interest and the plans for this pilot project, there is a clear need to expand this CXML data to include other tropical cyclone parameters relating to intensity and structure or to supplement the CXML approach with real-time exchange of additional TIGGE fields (e.g., 850 hPa winds, precipitation). It is critical that the research results from the NW Pacific TC project and other pilot projects (e.g., verification, evaluation of different multi-model approaches) feed into the GIFS-FDP for the SWFDP.

The precipitation group will establish access for the participants to precipitation forecast data from the various ensemble generating centers in real time and initiate the development of products focused on high-impact precipitation events. It is envisaged that GIFS prototype products will be based on forecasts contributed by one or more TIGGE and TIGGE LAM data providers. Concurrent with this initiative, new products under consideration, including multi-model combination products, will be verified, to demonstrate their potential value in a GIFS prototype implementation. For verification of precipitation forecasts, GIFS-FDP will explore the use of gridded precipitation analysis datasets, such as CMORPH. While the NW Pacific TCproject allows an efficient approach to the generation of products for the TC component of the GIFS-FDP, no such pilot effort exists yet for heavy rainfall. GIFS-FDP will explore opportunities to leverage testing of new precipitation products with future FDPs.

Finally we note that with time interest groups will be established to consolidate the results of TIGGE research and operational activities and expertise to focus on product development for other key areas of user needs (e.g., wind and precipitation) and to explore the development of “week-2” products, consistent with the THORPEX emphasis on accelerating the development of forecasting on the one-day to two-week time-scale.

Product development

GIFS products will require the application of a number of statistical procedures, including:

i) Unconditional bias correction of individual ensemble members to ensure they are all statistically consistent with NWP analysis

ii) Combination of information from all ensemble members (calibration, including conditional bias correction, affecting also higher moments)

iii) Statistical downscaling calibrated NWP ensemble forecasts to user relevant variables on high resolution grids

Products will be designed in consultation with user groups, including users in the relevant GIFS-FDP regions and the WWRP-SERA working group.

IMPLEMENTATION PLANS FOR GIFS PROTOTYPES

By late 2010, separate detailed implementation plans will be developed for

• Tropical Cyclones (TC)
• High Impact Precipitation (HIP)

Access to ensemble forecast data

Since the aim of GIFS is to prepare for the delivery of public weather services, especially warnings of high-impact weather, its data policy will be developed to allow sufficient distribution of data for products to be generated and cascaded to NHMSs and users, particularly what is necessary for forecasts of high-impact weather events. Weather forecasts, however, are also a valuable commodity for many NHMSs. Therefore in general it will not be feasible to provide unfettered access to forecast data in GIFS. For GIFS-FDP, data access agreements will need to be established among participants to permit the exchange of data necessary for development and real-time distribution of GIFS products.

Since the GIFS-FDP will be run in parallel to the SWFDP, data distribution channels already established for the SWFDP regional subprojects will be used where appropriate (see below). Techniques, including sub-setting, will be developed to move small amounts of data needed for particular products.

Regional Subprojects

The eventual implementation of GIFS will build on the cascading and interactive structure developed and successfully used in the Southern Africa SWFDP. Since most events manifest themselves locally, disaster prevention and mitigation efforts occur on a national and regional scale. Global NWP centres will provide and statistically enhance ensemble forecast data, and generate some derived probabilistic forecast products. Regional centres (Regional Specialized Meteorological Centers - RSMCs) will coordinate high-impact event related activities amongst NHMSs in each region. For tropical cyclone predictions, the key regional centres will be the relevant Tropical Cyclone Warning Centres (TCWCs) or specialist TC RSMCs. The implementation and testing of LAM EPS systems, to be operated regularly or on demand, will be one of these activities. Finally, the NHMSs will disseminate forecast products and provide guidance in their respective service areas.

To demonstrate this process, regional GIFS-FDP subprojects will be established, to focus on delivery of high-impact weather products tailored to address the priorities of users in specific regions. These products will focus on improving the prediction of high impact weather events affecting that region, starting with tropical cyclones and heavy precipitation through careful verification studies from a meteorological and user decision-based point of view. Initially, it is planned that GIFS-FDP regional subprojects will be run alongside regional SWFDP subprojects, focusing on products that can supplement or replace the products already being delivered by the SWFDP, using similar delivery channels.

It is envisaged that initial regional subprojects will be set up for Southern Africa and the South West Pacific, where the SWFDP is already active. In the future, regional subprojects may also be established in South America (where a regional SWFDP is proposed), South Asia, including the Indian subcontinent (where the Monsoon and tropical cyclones have a high impact), and in the Arctic region (where WWRP considers the development of a Polar prediction system as a legacy of IPY).