WORLD METEOROLOGICAL ORGANIZATION
____________________
COMMISSION FOR BASIC SYSTEMS
WORKSHOP OF GLOBAL PRODUCERS OF
SEASONAL TO INTERANNUAL FORECASTS
GPC-SIF/Doc. 5.1 REV.
(07.2.2003)
ITEM: 5.1
Original: ENGLISH
Geneva, 10-13 February 2003
Generation and Availability of SI Forecast and Related Products by
WMC Melbourne/Australian Bureau of Meteorology
(Submitted by Mike J. Coughlan)
Summary and Purpose of the Document
This document provides a summary of the information to be presented
under Agenda Item 5.1
ACTION PROPOSED
Note and incorporate the information into future plans with respect to the
coordination of activities of global centres providing seasonal to interannual
forecasts and other related information.
GPC-SIF/Doc. 5.1 REV.
Introduction
The Australian Bureau of Meteorology (BoM) has systems for generating seasonal-toInterannual forecast guidance. These systems have many features in common with the main
functions required of a Global Seasonal to Interannual Forecast Production Centre
(GSIFPC). BoM therefore expresses its interest in performing such a role within the WMO
framework.
BoM believes it is important that NMHSs tailoring information from GSIFPCs for their own
end users receive adequate support (e.g. training, and perhaps some sort of supporting
review mechanism) to ensure that the end-user information has a sound scientific basis. A
major consideration is the need to convey the degree of uncertainty in GSIPPC products and
the potential for further uncertainty to be introduced at the value-adding stage. There is also
a major issue in terms of presentation and comprehension of this complex information, an
issue that remains large in many of the potential producing centres. BoM is therefore
encouraged by the presence of training in current planning and are keen to see that
component retain a high profile. The WMO/CLIPS project should continue to act as a
suitable vehicle for this purpose.
Special efforts should be made to ensure that the international infrastructure arrangements
are well coordinated with those groups leading scientific research. In particular, the Climate
Variability and Predictability Programme (CLIVAR) of the World Climate Research Program
is providing oversight and coordinating scientific research for SI prediction and, as such,
should be fully involved in the development and implementation of appropriate measures of
performance and skill. In this regard, it is useful to note that at the Bureau there is a strong
link between research and operational services, similar to the international arrangement.
There is very close cooperation and dialogue between the National Climate Centre, which
has the operational responsibility for SI activity in BoM, and the Bureau of Meteorology
Research Centre (BMRC), which has the responsibility for basic research and forecast model
development, including development of scientifically robust measures of model skill. In
contrast to numerical weather prediction, the assessment of long-range forecasts is severely
limited by the length of the modern climate record and so we will be relatively more
dependent on sage scientific advice and oversight and innovative methods for assessment
(e.g., using ensembles). The establishment of a robust international infrastructure that
recognises the ongoing need for close links between research and operations is a critical
component for success in this endeavour.
While current discussions are centred on the future utilization of global scale products from
forecasts based on dynamical systems, there remains in most active, operational centres a
heavy reliance on empirical and statistically based relationships in the actual derivation of
forecasts issued to end-users. Ultimately the balance will shift, as it did for shorter range
weather forecasting, to a greater reliance on dynamical model based forecasts that have
more potential for tackling the complex interactions of the climate system, and thus
developing new predictability, and can address the space and time scales relevant to
practical problems. At that time, they will be better able to interface with user-oriented
systems to provide wide-ranging and useful SI forecast products. Hence, there is no doubt
that the GSIFPC concept is an excellent starting point with enormous potential in the longer
term. However, developing useful forecast systems based on the GSIFPC information (e.g.
through downscaling or “statistical bridging”) is still very much a research issue, and progress
will be hampered by the typical constraints of the relatively short, available hindcast periods.
There might therefore be a danger that some members will look to the GSIFPC initiative as a
comprehensive source of SI products, and might then lower the priority of establishing
statistical forecast schemes. Given the lack of experience with CGCM-based systems, the
statistical schemes may prove more useful for some members for at least the next 5 years. It
is therefore important that the current limitations of the GSIFPC-based system being
GPC-SIF/Doc. 5.1 REV., p. 2
developed be clearly explained and that an appropriate balance be maintained between the
richness and complexity of the CGCM approach and the simplicity but proven effectiveness
of statistical schemes.
Summary of Products
Following is a succinct summary of the products currently generated by the Australian
Bureau of Meteorology and those planned in the near future. Note that the spatial domain of
many of the current operational SI products is restricted to the Australia continent.
Nevertheless, BoM is active in building capacity within the Pacific Region for nations to draw
on Australian experience and know-how to enable them to develop there own SI prediction
capabilities based on appropriate guidance material. How the concepts of a Regional
Climate Centre or its functions are implemented in the region is also the subject of discussion
amongst a number of interested RA-V countries.
In line with the BoM’s viewpoint that SI activity remains very much a matter for ongoing
research, many products carry an appropriate caveat. This will apply especially to the
foreshadowed products generated from CGCMs,
a) SI Forecast material

Sea-surface temperature forecasts from the BMRC-CSIRO Marine Research
experimental coupled atmosphere-ocean general circulation model (version 1),
including forecasts for the Niño 1,2,3 3.4 and 4 regions

3-month seasonal climate outlook products (Australia only)
- a media release containing a summary of seasonal outlooks for 3-month total
rainfall, and 3-month average Tmax, Tmin

South Pacific Seasonal Outlook Reference Material
- a monthly report emailed to a small number of Pacific Island NMHSs
- represents a collation of Bureau and other seasonal forecast information (future
uncertain), and background observational material
- has limited distribution so not exactly “freely” available to International Community

A survey of 12 international ENSO forecast models
- prepared operationally
- summary used in media releases, and made available through web

BMRC Outgoing Long Wave Radiation and 1-3 week predictions based on the MJO
- experimental now but will soon be operational

The El Niño Wrap-up
- An operationally produced overview of the status of El Niño, based on latest
forecasts and observational material
- Produced weekly of fortnightly, and made avaliable through the web

Southern Oscillation Index (SOI) analogue forecasts
- presently limited free distribution to International Community
- distributed to Australian subscribers
- extremely abbreviated summary distributed through monthly Climate Monitoring
Bulletin.
GPC-SIF/Doc. 5.1 REV., p. 3
Much of this information is produced on a monthly cycle and can be accessed at the
following two websites:
-
http://www.bom.gov.au/climate/ahead/
http://www.bom.gov.au/bmrc/clfor/cfstaff/matw/maproom/index.htm
b) Observational Data and Products

Real-time synoptic data from the Regional Basic Synpotic Network

Sufficient national synoptic and climatological data to permit the development and
updating of methods of downscaling

Monthly data and statistics on daily rainfall and temperature data (Australia). Monthly
data within one week of end of month

Global and regional maps of a range of atmospheric fields (including MSLP and
Outgoing Longwave Radiation), on a monthly basis

Sea surface temperature (SST) and subsurface temperatures – weekly and monthly
anomalies and normals over the global ocean

Analyses of surface wind-stress and global sections of ocean temperature to 400m
depth on a monthly basis

Southern Oscillation Index, weekly and monthly running means available within a few
days

Archival data, including metadata, sufficient to determine the monthly climatology of
the nation

Climate Atlases, station climate normals and other statistics relating to historical
percentiles, extremes, etc.

Historical data series for the SOI and NINO area SSTs
c) SI forecast and related products to be made available from the Australian
Bureau of Meteorology experimental CGCM-based SI forecast system
The mixed experimental/operational system will consist of an 8 month forecast every day
made in real-time (within a day or two). All products will be calibrated relative to the model’s
climate calculated as a function of lead-time and start month, using at least 15 years of hindcasts. The current research website is:
http://www.bom.gov.au/bmrc/ocean/JAFOOS/POAMA
Short Term (within 1 year)
Short-term products are those related to the forecasting of the ENSO phenomenon.
Forecast products:
1. SST anomalies for each ensemble member in pre-defined area averages (Nino 3,
Nino 4, Nino 3.4)
2. Monthly and/or seasonal gridded (on model grid in netcdf format) or plotted (gif files)
fields of ensemble mean (monthly) SST anomaly,
GPC-SIF/Doc. 5.1 REV., p. 4
Skill assessment products:
1. Based on at least 15 years of hind-casts and at least one forecast per month.
2. Anomaly correlation and rms errors corresponding to products above.
Long Term (next 2-3 years)
1. Above products in a standard format (if one is established, e.g. on a 2.5x2.5 grid).
2. Skill assessment of short-term products as required by WMO (eg. ROC scores, %
consistent scores etc)
3. Forecasts of global atmospheric variables: 2m temperature, precipitation, Z500, mslp,
T850, SOI + NAO indexes, etc
4. Skill assessment of products at (3) as required by standards set by WMO.
BoM believes that the production of forecasts of atmospheric variables (3 above) and the
assessment of the skill of the forecasts (4 above) remain research issues. It is therefore
premature at this stage to prescribe what products will be made available and how they will
be assessed.