Proposed Predictability, Dynamics & Ensemble Forecasting Expert Team

Richard SwinbankMasayuki Kyouda

GIFS-TIGGE WG, Exeter, June 2013

Contents

Post-THORPEX plansEvolution of GIFS-TIGGEProposed expert teamDiscussion…

33

WWRP structure

4

Legacy THORPEX

4

Subseasonal to Seasonal Prediction

Project

Polar Prediction

Project

High Impact Weather Project

JWGFVRWGNR

/MFR

WGTMRWGSERA

PCPI

WGSIP

WGNE

SWFDP

MJO TF

WGDAOS WGPDP

5

WWRP structure and links to WCRP

5

TIGGE – Research focus

The TIGGE project (& GIFS-TIGGE working group) was originally focused on the technical work enabling the establishment of the TIGGE archive dataset. The main scientific aspects of THORPEX were covered by Predictability & Dynamical Processes WG, and also Data Assimilation & Observing Systems WG(s).Following the successful establishment of the TIGGE dataset, the focus of the GIFS-TIGGE working group has shifted towards research on ensemble forecasting. Particular topics of interest include:

a posteriori calibration of ensemble forecasts; combination of ensembles produced by multiple models; research on and development of probabilistic forecast products.

More recently, we have broadened our range of interest to cover improvement of EPSs, including:

representing uncertainties in initial conditions stochastic physics & other techniques to account for model error

Virtuous Circle

Develop,Improve

Evaluate,Diagnose

Ensemble Forecasts

To improve EPSs we need to develop a virtuous circle – best with a single group with focus on ensemble prediction

TIGGE development

Calibration, combination, products

EPS improvement

Time

Evolution of TIGGE & GIFS

GIFS-TIGGE should also be a forum to focus on R&D directed at improving our EPS systems, to help us develop a “virtuous circle”.

We introduced a section of the WG meeting for discussing ensemble initial conditions, stochastic physics & other aspects of improving our EPSs.

We also need to maintain an interest in ensemble verification & links with convective-scale EPS and the new sub-seasonal to seasonal group.

Looking forward -A proposed new working group

The logical evolution of an increased focus on research would be the creation of a Predictability Dynamics & Ensemble Forecasting working group, combining much of the current GIFS-TIGGE and PDP groups.

This new group would provide a centre of scientific expertise on dynamics, predictability and ensemble forecasting that is currently lacking in the core WWRP programme.

Scope

A centre of scientific expertise on dynamics, predictability and ensemble forecasting

Bridge between academic & operational communities Promote use of TIGGE and TIGGE-LAM Scientific issues include

Growth & evolution of errors Stochastic representation of unresolved processes

Short- to medium-range forecast timescales (potentially longer)

Relationship with other teams / groups

Clear linkages with WGNE and other WWRP expert teams

Numerical modelling, ensembles, data assimilation, stochastic parameterization & evaluation all closely linked on weather forecast & climate timescales.

Too big for a single expert team – need a set of more specialised teams.

Providing expert support to WWRP projects (S2S, PPP, HIW, RDPs & FDPs)

Other issues

Development of severe weather products Would fit well into scope of proposed HIW project

Technical management of data archives Ongoing management could be done by a liaison group of

archive centres & some or all data providers. Could report to PDEF team (or HIW project)? Representative

of technical group on ET.

Transition arrangements Work towards merger of GIFS-TIGGE and PDP groups at end

of 2014 New members of both groups chosen for role in new team.

Next Steps

Discuss here and at joint THORPEX/ICSC and WWRP/JSC meeting.

What is the process for approving the new group?