S2S News Letter

No. 4October 1, 2016

News Letter
S2S Forecast Products available at ECMWF
A new range of near-real time forecast charts based on the Subseasonal to Seasonal predictions (S2S) database is now openly
available at: www.ecmwf.int/en/research/projects/s2s/charts/
s2s/.
They can be used to monitor the S2S data and assess the quality of
the forecasts, as well as providing a testbed for the development of
new products, for example to identify signals for extreme events atthe sub-seasonal timescale. The products include ensemble mean
anomalies for some meteorological parameters, Extreme Forecast
Index (EFI) for 2m temperature and forecasts of the Madden andJulian Oscillation (MJO). Since S2S is a research project, theforecasts are available with a 3-week delay; they are not intended
for operational use.
As an example of S2S products Figure 1 shows weekly mean
precipitation anomalies with verification and forecasts fromdifferent models. This figure gives an idea of how well thepredicted anomalies verified against the ECMWF analysis and also
about the consistency between the different S2S forecasts.

ContentsNews:
S2S Forecast Products available at
ECMWF
1S2S Side Event at the WMO Executive
Council
1
The S2S Museum by Mio Matsueda 3
MAPP: A New NOAA Initiative on Subseasonal to Seasonal Prediction 5International Workshop on the
Madden-Julian Oscillation
6

Topics:What is S2S?
1S2S ICO at NIMR in Jeju
1
Six Sub-projects in S2S
2Upcoming Events
5
Applications of S2S Forecasts: From
Disaster Early Warning to Early Action
6

What is S2S?

Fig. 1: Weekly mean precipitation anomalies for 18-24 January 2016 from Era
Interim (top left panel), ecmwf (top right panel), bom (bottom left) and jma(bottom right). The anomalies are computed relative to the model climatology overthe common period 1999-2010.

S2S Side Event at the WMO Executive Council
The World Weather Research Programme (WWRP) and the World
Climate Research Programme (WCRP) held a side event entitled“From Sub-seasonal prediction to action” on 21 June 2016 in
Geneva during the WMO 68th session of the Executive Council. The
meeting was attended by around 40 people, including several WMO
Presidents of Technical Commissions and Regional Associations.
Deon Terblanche, co-director of the Research Department, recalled
the importance of the sub-seasonal to seasonal (S2S) timescale(from two weeks to two months ahead), as many management
decisions in agriculture and food security, water availability,
disaster risk reduction and health fall into this range. He further
S2S News Letter

To bridge the gap between
medium-range weather forecasts
and seasonal forecasts, the World
Weather Research Programme( W W R P ) a n d Wo r l d C l i m a t e
Research Programme (WCRP)
launched a joint research
initiative in 2013, the Subseasonal
to Seasonal Prediction Project(S2S). The main goal of thisproject is to improve forecast skill
and understanding of the subseasonal to seasonal timescale,and to promote its uptake byoperational centres and exploitation by the applications communities. The web-site is at http://s2sprediction.net.

S2S ICO at NIMS in Jeju
The S2S International Coordination
Office (ICO) is located at the
National Institute of Meteorological Sciences (NIMS) of the
Korea Meteorological Administration (KMA), in Jeju, Republicof Korea. The primary function of
the ICO is to provide support toplanning and implementation of
S2S priorities.
1S2S News Letter

Six Sub-projects in S2S
The research topics of the WWRP/
WCRP Sub-seasonal to Seasonal
Pr e d i c t i o n p r o j e c t ( S 2 S ) a r eorganized around a set of six subprojects, each intersected by thecross-cutting research and modellingissues, and applications and userneeds. The science plans of each sub
project which can be found at the
S2S webpage, include:

1. Monsoons: The main goal of thissub-project is to develop a set ofsocietally relevant intra-seasonal
forecast products and metrics thatare applicable to all the major
monsoon systems which can bemonitored with operational real-time
forecast systems. Case studies of
monsoon onsets will be investigated.
2. MJO: This sub-project will evaluate the state of the art andcharacterize shortcomings of MJOMaritime Continent interactions. A
main goal is to get a better understanding of the roles of multi-scaleinteractions, topography and landsea contrasts, and ocean-atmosphere
coupling in collaboration with the
MJO Task Force of WGNE and Year of
the Maritime Continent (YMC).

3. Africa: The goal of this sub-project is to develop skilful forecasts
on the S2S time scale over Africa andto encourage their uptake by national
meteorological services and otherstakeholder groups. This sub-project ismore application oriented than theother sub-projects.

4. Extremes: This sub-project will
evaluate the predictive skill andpredictability of weather regimes andextreme events (droughts, floodings,
heat and cold waves), assess thebenefit of multi-model forecasting for
extreme events and improve ourunderstanding of the modulation of
extreme weather events by climate
modes. It is also planned to select casestudies with strong societal impact.

5. Products and Verification:

The main goals of this sub-project are
to recommend metrics and datasets forassessing the forecast quality of S2S
forecasts, provide guidance for apotential centralized effort forcomparing forecast quality of different
S2S forecast systems, including thecomparison of multi-model andindividual forecast systems andconsider linkages with users andapplications.

No. 4October 1, 2016

stressed the significant socio-economic value which could be
drawn from improved weather-to-climate forecasts tailored to
key society needs. He expressed his gratitude to both theEuropean Centre for Medium-Range Weather Forecasts (ECMWF)
and the China Meteorological Administration (CMA) for hosting
the sub-seasonal to seasonal database. The collection of the
global sub-seasonal prediction systems provides a fundamental
tool for sub-seasonal to seasonal research, and also the basis fora likely future transition to operations of these pilot products toserve society in a wide variety of sectors. He finally thanked the
Korea Meteorological Administration for hosting the S2S project
office in Jeju, Republic of Korea.
Florence Rabier, Director General of the European Centre for
Medium-Range Weather Forecasts (ECMWF) presented thecenter’s vision on Sub-seasonal Prediction as part of a broader
strategy covering medium range to seasonal and extended range
predictions and its potential for a wide range of applications. She
noted the numerous sources of predictability and recent science
progress on sea surface temperatures, land surface conditions,
the Madden Julian Oscillation, stratospheric variability,
atmospheric dynamical processes and sea ice cover. She
concluded on the critical role of the S2S project to accelerate
progress, as many challenges remain to secure predictive skill
beyond 3 weeks for most regions.
Rafael Terra, Facultad de Ingeniería, Universidad de la Republica,
Montevideo, Uruguay illustrated the benefit of climate forecasts
in the agro and energy sectors in his country. The optimal
management of water reservoirs can represent savings on theorder of 20% of the annual costs to meet demand. An integrated
electric system simulator allows optimal water storage
adjustments to seasonal planning with appropriate gasoilpurchase at the subseasonal timescale. He concluded on thepotential for S2S predictions to improve preparedness andresponse and to adjust the mix of crops, input use, fertilizer split
applications, pasture management and grazing rate.
Andrew Robertson from the International Research Institute for
Climate and Society (IRI), Columbia University, New York, USA,reviewed the role of S2S in promoting science and services in
WMO regions. An integrated decisional framework such as the
READY, SET, GO, being developed by the Red Cross and IRI, where
seasonal forecast provide READY information, sub-seasonal the
SET and weather forecast the GO stage, illustrates the potential
benefit of the S2S project for several sectors. He invited theaudience to further develop the S2S project in several practicalapplications, including improving food security and preparedness
to drought and floods in Sub-Saharan Africa, Ganges basinhydroclimate forecasting, South American climate services forenergy, agricultural and water resource management, and heatwave early warning in South Asia.
Presentations are available from the S2S web page at http://s2sprediction.net/static/meetings#2016.

6. Teleconnections : This sub-project aims at a better under-standingof sub-seasonal tropical-extratropicalinteraction pathways and identifying
periods and regions of increased
predictability (“forecasts ofopportunity”). This would help improvesub-seasonal to seasonal forecasts ofweather and climate for applications.

S2S News Letter

A snapshot at the S2S Side Event2

S2S News Letter

No. 4October 1, 2016

The S2S Museum
Mio Matsueda
Center for Computational Sciences, University of Tsukuba
Department of Physics, University of Oxford
The Subseasonal to Seasonal Prediction (S2S) Project is a proposed WWRP/THORPEX/ WCRP joint
research project. The main goal of the S2S project is to improve forecast skill and understanding on thesubseasonal to seasonal timescale, and promote its uptake by operational centres and exploitation by
the applications community. Specific attention will be paid to the risk of extreme weather, including
tropical cyclones, droughts, floods, heat waves and the waxing and waning of monsoon precipitation.
The S2S data portals freely provide the S2S ensemble forecast datasets from 10 numerical weather
prediction (NWP) centres, with a 3-week delay only for research and education purposes.
The S2S Museum website was established by Dr. Mio Matsueda (Universities of Tsukuba and Oxford)
and is hosted by the Center for Computational Sciences at the University of Tsukuba (at http://
gpvjma.ccs.hpcc.jp/S2S/), similar to the TIGGE Museum (http://gpvjma.ccs.hpcc.jp/TIGGE/) based on
medium-range ensemble forecasts. The S2S Museum displays a variety of forecast products based on the
S2S dataset, including forecasts of• the Arctic/Antarctic Oscillation (AO/AAO) indices;• the North Atlantic Oscillation (NAO) index;• teleconnection pattern indices (the Pacific/North American (PNA), the Western Pacific (WP),
and the Eurasian (EU) pattern indices);• wave activity flux at 200 hPa;
• the Sudden Stratospheric Warming (SSW);• the Madden–Julian Oscillation (MJO);• sea surface temperature; and• sea-ice cover.
The products are regularly updated every day, with a 21-day delay and are available for noncommercial use. Other forecast products including atmospheric blocking and early warning of severe
weather events available at the TIGGE Museum, are planned to be added to the S2S Museum.
Here are three examples of the forecast products. The first example is real-time multivariate MJO
index (Wheeler and Hendon, 2004) forecasts, initialised on 12th March 2015 (Fig. 1, note that all
operational centres do not conduct S2S ensemble forecasts every day). Some of the ECMWF ensemble
members predicted the MJO propagation well up to a lead-time of +20 days (yellow-green circle),
whereas the other NWP centres failed to predict it even at a lead-time of +8 days (blue circles).

Figure 1 (top left) NCEP control analysis for real-time multivariate MJO index for the 90 days prior to theinitial date of the forecast. (right 9 panels) Real-time multivariate MJO index forecasts by BoM (top left,
Australia), CMA (top centre, China), ECMWF (top right), and NCEP (bottom, US), initialised at 00 UTC 12th
March 2015. The black circle and the black line with numbered circles correspond to the NCEP control
analysis. The numbers in the coloured circles indicate the number of days from the initial date. The
coloured lines indicate ensemble members. The colour changes reflect the lead-time of the forecasts.

S2S News Letter3

S2S News Letter

No. 4

Figure 2 NAO index forecasts by CMA (aqua), ECMWF (blue), ISAC-CNR(yellow, Italy), NCEP (green) and UKMO (purple), initialised on 28th
December 2015. The coloured and grey lines indicate individual ensemble
members and ensemble mean, respectively. The black line corresponds to
the NCEP control analysis.

October 1, 2016
The second example is NAO
index forecasts initialised on 28th
December 2015 (Fig. 2, nextpage). The phase of the observed
NAO changed from positive tonegative on 3rd January 2016 andthen changed from negative topositive on 24th January 2016. The
first transition from positive
phase to negative phase was well
predicted by all the NWP centres,
except CMA. However, most ofensemble members predictedshorter persistence of thenegative phase of the NAO withweaker amplitudes thanobservation. The ECMWF
ensemble mean predicted thetiming of the transition fromnegative phase to positive well,followed by the NCEP and UKMO
ensemble means, although thepredicted amplitudes of thepositive phase of the NAO weremuch smaller than observation.
The third example is ensemble
mean forecasts of sea surface
temperature and sea ice cover,initialised on 8th September 2016,valid on 29th September – 5th
October 2016 (Fig. 3). Althoughsome models are not coupled witha sea ice model (e.g. BoM, ECCC,
and ECMWF), there are large
pattern differences of sea ice
cover even among the NWP centreswith a sea ice model. This suggeststhat large differences ofatmospheric responses to sea ice
cover can be seen among models.

Figure 3 (left) Sea surface temperature(colour bar at the lower-right corner)and sea ice cover (colour bar at theupper-right corner) forecasts by BoM(yellow-green), CMA (aqua), ECMWF(blue), ECCC (yellow, Canada), METFR(brawn, France), NCEP (green) and
UKMO (purple), initialised on 8 th
S e p t e m b e r 2 0 1 6 , v a l i d o n 2 9th
September – 5th October 2016.

Reference
Wheeler, M. C., and H. H. Hendon (2004), An all-season real-time multivariate MJO index: Development of
an index for monitoring and prediction, Mon. Wea. Rev., 132, 1917 – 1932.

S2S News Letter

4S2S News Letter

No. 4

MAPP: A New NOAA Initiativeon Subseasonal to Seasonal Prediction
The NOAA Climate Program Office’s Modeling, Analysis,
Predictions and Projections (MAPP) Program has initiated a threeyear Subseasonal to Seasonal (S2S) Prediction Task Force. This
MAPP Task Force seeks to make a significant researchcontribution to the WWRP/WCRP S2S Prediction Project as it
helps close the gap between weather and seasonal predictions
and products.
The core membership of the MAPP Task Force constitutes
scientists from universities, research laboratories, and modelingcenters leading 14 new research projects. These projects wereselected for funding through a MAPP Program grant competition
on research to advance the modeling and prediction ofphenomena that are potential sources of S2S predictability. The
NOAA National Weather Service Office of Science and Technology
Integration also contributed support for these projects.
Through monthly teleconferences and occasional in-person
meetings of opportunity, the Task Force provides a mechanism forscientists to share new datasets, methodologies, and results. The
Task Force held its first monthly teleconference on September
16th, in which more than 40 researchers participated. The Task
Force plans to synthesize its research efforts through technicalreports, review articles, and/or journal special collections, andto engage with the broader research community via workshops
and meeting sessions.
The WWRP/WCRP S2S Prediction Project database will serve as a
key resource for the S2S Prediction Task Force as its members
carry out research to examine how the prediction of S2S
phenomena is influenced by the prediction system setup (forexample, choice of physics, horizontal grid spacing, orrepresentation of the stratosphere). They will be exploring suchphenomena as the Madden-Julian Oscillation, the North Atlantic
Oscillation, tropical–extratropical teleconnections, extratropicalstorm tracks, blocking events, stratospheric flow regime
transitions, and land surface and ocean interactions with theatmosphere.
To establish an immediate link with the WWRP/WCRP S2S
Prediction Project, the Task Force will convene an in-person kickoff meeting on December 5th, 2016, in conjunction with theDecember 6th-7th Workshop on S2S Predictability of Extreme
Weather and Climate sponsored by in part by the S2S Project.
The Task Force is led by Elizabeth Barnes (Colorado State
University), and co-led by Edmund Chang (Stony Brook
University), Paul Dirmeyer (Center for Ocean-Land-Atmosphere
Studies/George Mason University), and Andrea Lang (University at
Albany). The Task Force also includes researchers with projects
associated with SubX – a new interagency prediction system
experiment to test subseasonal ensemble prediction systems forpossible operational use by the National Weather Service. SubX
was initiated by the MAPP Program and is jointly supported by
MAPP, NASA, the National Weather Service, and the Departmentof Defense’s Office of Naval Research. Scientists from thebroader research community will also be invited to join the Task
Force on a case-by-case basis.
To learn about the MAPP projects led by the researchers
associated with the S2S Prediction Task Force, visit http://
cpo.noaa.gov/MAPP/S2STF.

October 1, 2016
Upcoming Events

Workshop on Sub-Seasonal to
Seasonal Predictability ofExtreme Weather and Climate
6-7 December 2016, IRI
T h e I n t e r n a t i o n a l Re s e a r c hInstitute for Climate and Society( I R I ) , C o l u m b i a U n i v e r s i t y ’s
Extreme Weather & Climate
Initiative, and the WWRP/WCRP
Sub-Seasonal to Seasonal
Prediction Project (S2S) will hold a2-day workshop on December 6-7
2016 at the Columbia University
Lamont-Doherty Earth Observatory
campus in Palisades, New York.
This workshop is intended for all inacademia, government, and theprivate sector with an interest inunderstanding the latest sciencebehind S2S predictability of
extreme weather and climate, andin developing early warning
products. Through a small set ofinvited talks, contributed posters,
and discussion sessions theworkshop will showcase the latest
research on extremes using S2Smodels, and provide an
opportunities for networking andunstructured discussion.
Topics will include: the international S2S research init-iativeand data archive, ope-rational S2S
forecasting, private sector forecasts, sources of S2S predictabilityof weather extremes, and risk
management perspectives.
More information on the workshop
is available at http://iri.
columbia.edu/s2s-extremesworkshop-2016/.
This workshop will be followed by
a 2-day closed meeting of the S2Ssteering group (8-9 December2016).

WWRP Science Steering
Committee Meeting
24-27 October 2016, WMO
The World Weather Research
Pr o g r a m m e ( W W R P ) S c i e n c e
Steering Committee (SSC) meeting
will be held at WMO Headquarterin Geneva, 24-27 October 2016, to
discuss the status and the future
plan of the activities under the
Programme.

For questions about the MAPP S2S Prediction Task Force, contact
Heather Archambault (heather.archambault@noaa.gov).
S2S News Letter5

S2S News Letter

No. 4October 1, 2016

Applications of S2S Forecasts:
From Disaster Early Warning to
Early Action

International Workshop on the Madden-Julian
Oscillation, 6–9 August, Chengdu, China

S a r a h B a s h f o r d Ly n a g h , A n d r e w
Robertson, Roop Singh
Climate and Society MA Program,
Columbia University

The International Workshop on MJO was held in Chengdu from 6
to 9 August, hosted by the Institute of Atmospheric Physics (IAP),
Chinese Academy of sciences (CAS), Chengdu University ofInformation Technology (CUIT). The purpose of the Chengdu
International Workshop on the Madden-Julian Oscillation was tosynthesize our current understanding of dynamics of the MJO, its
impacts on global weather-climate, and its predictability.
It was organized into eight sessions (Overviews, Impacts on
Weather-Climate, Observations over the Maritime Continent,
Extratropical Intraseasonal Oscillation, Dynamics, Theories,
Modeling, Prediction and Predictability) and a poster session. 128
scientists and students from 39 institutes and universities of 7
countries attended the workshop. 37 talks and 29 posters were
presented. All presentations are posted at http://
www.lasg.ac.cn/mjo-workshop/.
MJO Modeling

Shifting the Conversation from
Response to Resilience
The international dialogue on disaster
preparedness and response has
undergone a paradigm shift in the last
10 years. The focus has switched fromone of managing disaster impacts to oneof managing disaster risks, with agreater attention placed on increasing
resilience of communities and nations.
This is at the core of the Sendai
Framework for Disaster Risk Reduction
2015–2030.
The Red Cross Red Crescent Climate
Centre (RCCC) is one of theorganizations working to foster
preparedness by developing “forecastbased financing” in which a weather or
climate forecast is used to trigger the
release of funds and other actions inadvance of a natural hazard. The“Ready-Set-Go” framework, jointly
developed by the International ResearchInstitute for Climate and Society (IRI)
and RCCC, describes a seamlessapproach for acting based upon
forecasts with different lead times. This
framework recognizes that forecasts canbecome more specific as a potential
disaster approaches, but that thatspecificity comes with less time to act.
In particular, sufficiently accurate
subseasonal-to-seasonal (S2S; those in
the two week to three month range)
forecasts would hold an important place
within this hierarchy of decision scales,
informing the medium-term risk
management actions within acommunity.
The BRACED Program
The Building Resilience and Adaptation
to Climate Extremes and Disasters
Program (BRACED), brings together 108
organizations working in 15 consortiums
across 13 countries in the Sahel, East
Africa, and Asia to ensure climate-smart
development in the face of climate
shocks and extremes and foster longterm resilience and adaptive capacity.
BRACED projects seek to tackle themultifaceted challenges associated withextreme events. They range fromfinancial solutions, to collecting
floodwaters for gardening, to changing
agricultural practices to better prepare
for heavy rains. With a mind towards
long-term development, the approach is
to improve disaster risk reduction andclimate adaptation practices to foster
resilience from the local level up to theinternational.
For more information on the BRACED
Program and the ongoing work in
climate resilience, please see: http://
www.braced.org/. (Read the original at
http://s2sprediction.net/file/d o c u m e n t s _ r e p o r t s /Blog_S2S_DRR_Lynagh2016.pdf)

S2S News Letter

The improvement in certain aspects of the simulated climate byusing the “super-parameterization” is accompanied withdeterioration in others (Zhenning Li). Most global models thatare capable of producing a realistic MJO display a realistic
sensitivity of their parameterized convection to environmental
moisture, a convective adjustment time scale in response to
departures from the moisture “quasi-equilibrium” state, andvertical profiles in temperature, humidity, and diabatic heating(Eric Maloney, Xianan Jiang). Wind-induced upper-ocean coolingin a coupled model facilitates MJO eastward propagation by
suppressing convection to the west (Shuyi Chen). Eastward
propagation of the MJO in a global cloud-permitting model(NICAM) is sensitive to surface latent heating flux, especially in
the Maritime Continent (MC), but not to the reproduction ofcloud-clusters and synoptic equatorial waves (Tomoki Miyakawa).
Coupling this model to an ocean model introduced SST biases
that deteriorated MJO simulations. Coupling may not improve
the skill of MJO prediction in a forecast model (Hongli Ren) but
may improve it in another model if more accurate SST is
produced (Xiaqiong Zhou).
Prediction and Predictability
Predictability of precipitation over the USA is enhanced by the
MJO with its error growth slower than those on other scales, but
is limited by errors on small scales unrelated to the MJO (Charles
Jones). Ensemble forecast has improved MJO prediction skills at
the Beijing Climate Center by four (16 to 20) days with better
representations of MJO impacts on extratropical weather (Hongli
Ren). MJO forecast skills by the NCEP forecast systems vary fromyear to year, with useful skill ranging from 15 to 30 days
(Xiaqiong Zhou). Stochastic perturbation ensembles improve themodel mean state and variability, especially over the MC (Shuyi
Chen). There is no clear relationship between spread and skill
among different models (Frederic Vitart). MJO prediction skill ishigher during easterly than westerly phases of the QBO in boreal
winter (Yuna Lim) A new method of evaluating MJO prediction
skill has been proposed, mean tendency vectors defined as the
direction of anomaly correlation coefficient and the root-meansquare error in the RMM phase diagram can be used to define
forecast errors (Yuiko Ichikawa). Futhermore, a new
methodology was proposed for diagnosing MJOs by tracking
large-scale precipitation events (Shuyi Chen).
In summary, the workshop presented most recent progress in the
study of the MJO study and identified gaps in our knowledge ofunderstanding its global impact, dynamics, and predictability.
Sub-seasonal to Seasonal Prediction Project International Coordination Office
National Institute of Meteorological Sciences, Korea Meteorological Administration
33 Seohobuk-ro, Seogwipo-si, Jeju 63568, Republic of Korea
Web site: http://s2sprediction.net E-mail: tetsu_nakazawa@icloud.com
Tel.: +82-64-780-6653
Fax: +82-64-738-9075

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