Page 1 Pacific THORPEX Predictability, 6-7 June 2005© Crown copyright 2005 The THORPEX Interactive Grand Global Ensemble David Richardson Met Office, Exeter

© Crown copyright 2005 Page 1Page 1Pacific THORPEX Predictability, 6-7 June 2005

The THORPEX Interactive Grand Global Ensemble

David Richardson

Met Office, Exeter


Contents

Global Interactive Forecast System concept

The THORPEX Interactive Grand Global Ensemble (TIGGE)1st TIGGE WorkshopFuture plansLinks to Pacific Experiment

The presentation covers the following sections


Traditional forecast system

observations Assimilation Forecast users


Global Interactive Forecast System

Initial risk from medium-range global ensemble

Forecaster runs ‘sensitive area’ prediction

Forecaster requests observations in sensitive areaForecaster requests

high resolution regional ensemble

Initiate and maintain links with civil protection agencies


Global Interactive Forecast System (GIFS)

A concept for future weather prediction

Global Global participation, global application, global and regional

models

Interactive observation-assimilation-forecast-user: all parts of system

integrated, adaptive, interactive. Changes according to situation and user needs.

We cannot say now what a future Global Interactive Forecast System will be – a goal of THORPEX is to determine this

The development, evaluation and testing of a future GIFS will depend on results from all four components of THORPEX


THORPEX Interactive Grand Global Ensemble (TIGGE)

Framework for international collaboration in development and testing of ensemble prediction systems

Resource for THORPEX research projectsComponent of THORPEX Forecast Demonstration

Projects (FDPs)A prototype future Global Interactive Forecast

System Initially develop database of available ensembles,

collected in near-real timeCo-ordinate research using this multi-model

ensemble data, including interactive aspects


TIGGE Workshop

Workshop: 1-3 March 2005, ECMWFAddress strategy to achieve TIGGE objectivesFocus on user-requirements and infrastructure

needed to meet theseProduce outline plan and timetable60 participants from operational centres and

universities worldwideReport submitted to THORPEX Executive Board

and International Core Steering Committeewww.wmo.int/thorpex/publications.html


TIGGE Workshop: aims

Aim: Define user-requirement for TIGGE dataUsers

Who?What for?How?When?

RequirementsWhat data?Format?How to access?

ContributorsEPS 1 EPS 2 EPS n

NHMS academic End user

Predictability science

Real-worldapplications

???


TIGGE infrastructure Phase 1

Data collected in near-real time (via internet ftp) at central TIGGE data archives

Can be implemented now at little cost

Can handle current data volumes within available network and storage capabilities

TIGGE Centre A

EPS 1 EPS 2 EPS n


TIGGE Centre B




TIGGE infrastructure Phase 2

Data distributed over several repositories

But keep efficient and transparent user access

Flexible – minimise data transfers

Needs substantial software development

Coordination with WMO Information System

Requires additional funding EPS 1 EPS 2 EPS n




Portal to distributed (virtual) archive


Access and use of TIGGE data

Aims for TIGGE data policy:TIGGE data available to all users for research

purposes (efficient approval for data access)

User-friendly interface for access to the central archives (including for subsets of ensemble data)

Promote open-source sharing of post-processing software (calibration, combination, decision-making) to maximise benefit for both researchers and end-users

Address issue of real-time access to data, in particular for demonstration projects and field experiments


TIGGE Plans

Phase 1: Central TIGGE archives: ECMWF (NCAR, CMA) For ECMWF: funded within existing resources Technical plan: July 2005 Initial infrastructure development: Jan 2006 Early 2006: TIGGE data archives will begin collecting

available ensemble contributions in near-real time 2007-08: TIGGE available for THORPEX support to

demonstration projects (IPY, Beijing 2008 Olympics regional EPS, Pacific THORPEX Experiment)

Phase 2: distributed archive Coordinate with WMO Information System plans ECMWF will lead bid for FP6 funding


TIGGE and Pacific Predictability Experiment

Predictability studies – inter-comparison of different available ensemble systemsAre all models equally poor over W N America?Are better models still relatively worse here than

elsewhere? Are analyses relatively worse over Pacific?Does better use of satellite data improve

performance? Is predictability intrinsically low?How important is model error?


TIGGE and Pacific Predictability Experiment

Predictability studies – inter-comparison of different available ensemble systems

Field campaign support Real-time access to global TIGGE ensemble forecasts Advance warning of potential significant events Sensitive area predictions incorporated in TIGGE

infrastructure (some SAP also directly use TIGGE ensembles)

Regional ensembles Boundary conditions from global TIGGE ensembles Regional ensembles into TIGGE archives Co-ordinated inter-comparison of performance Global TIGGE predictions of when to run regional/mesoscale

ensembles


Northern hemisphere 500 hPa ACC

Impact of removing most in-situ observations

COMB operational Met Office

systemBASE

All satellite data GUAN radiosonde GSN land stations

(pressure only) Ocean buoy data (no ships)

Documents

Page 1 Pacific THORPEX Predictability, 6-7 June 2005© Crown copyright 2005 The THORPEX Interactive Grand Global Ensemble David Richardson Met Office, Exeter