New Seasonal Prediction System SEAS5 Brings Better El Niño Forecasts

PR70952

READING, England, Nov. 10, 2017 /PRNewswire=KYODO JBN/ --

The European Centre for Medium-Range Weather Forecasts (ECMWF) today launches

its latest seasonal prediction system, SEAS5. The system brings a substantial

improvement in forecast skill, especially for El Niño/La Niña events. Forecasts

are also more detailed thanks to much greater horizontal resolution. An

immediate application is the use of SEAS5 by the Global Flood Awareness System

(GloFAS) to create the first ever operational global long-range river-flow

forecasting system. This could mean much earlier awareness of floods and

droughts than has previously been possible.  

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Seasonal forecasts help to give an idea of large-scale weather patterns up to

seven months in advance at the moment. ECMWF's strategic goal is to extend this

to a year by 2025. The forecasts can support decision-making for users ranging

from governments and aid agencies to businesses, in areas such as water and

energy management, health, agriculture and financial services.

ECMWF has been providing seasonal forecasts for 20 years. The forecasts are

best known for successful predictions of El Niño and La Niña events. These

periods of anomalous warming or cooling in the tropical eastern Pacific have a

strong impact on the weather locally, but also influence global weather

patterns. SEAS5 brings noticeable improvements in forecast skill for El Niño/La

Niña and for the tropics more generally. Predictions of Arctic sea ice and

near-surface temperature in the northern hemisphere are also improved, notably

as a result of including an interactive sea-ice model in SEAS5.

Horizontal resolution has more than doubled both in the ocean model (from 1

degree to 0.25 degrees) and in the atmospheric model (from 80 km to 36 km),

enabling much more detailed forecasts.

ECMWF project lead Tim Stockdale said: "SEAS5 uses a version of ECMWF's

state-of-the-art Integrated Forecasting System (IFS) and represents six years

of model development. The resolution upgrade is a huge step forward,

particularly in the accuracy of representing the global ocean. The influences

of the land surface are also better represented. For the future, a major goal

is to improve predictions for the stratosphere to make the maximum use of all

sources of predictability."

SEAS5 represents an important step towards ECMWF's goal of seamless forecasting

across all time ranges. The model and initialisation methods are almost

identical to those used for ECMWF's medium- and extended-range ensemble

forecasts (ENS). This greatly facilitates model development and maintenance.

ECMWF Member States and licensed users can access SEAS5 forecasts on the 5th

day of each month. The forecasts are made available more widely on the ECMWF

website (http://www.ecmwf.int) on the 10th of each month. The forecasts can

also be accessed on the 10th of each month through the EU-funded, ECMWF-run

Copernicus Climate Change Service (C3S) (http://climate.copernicus.eu/). C3S is

developing a seasonal forecast service which also includes forecasts from other

centres and multi-system forecasts.

The Global Flood Awareness System (GloFAS) is co-developed by ECMWF and the

Joint Research Centre of the European Commission as part of the Copernicus

Emergency Management Service (EMS). The new seasonal GloFAS model, developed in

collaboration with researchers from the University of Reading, takes long-range

forecasts from SEAS5 and runs a hydrological model to simulate how the

predicted conditions will impact river flow across the globe up to four months

in advance.

Initial pre-implementation tests indicate that the new model has the potential

to save lives by allowing authorities and aid agencies around the world to plan

and prepare flood relief efforts earlier than ever before. Other potential uses

include water resource management, agriculture and disaster risk reduction.

Project lead Rebecca Emerton, a flood forecasting PhD researcher at the

University of Reading and visiting scientist at ECMWF, said: "This new model

could be a game-changer in that it provides hydrologically relevant forecasts

out to several months for the whole globe - something that has never been

possible before. It has the potential to provide earlier indications of both

floods and droughts, which could be invaluable for disaster risk reduction

efforts around the world, helping vulnerable communities become more resilient

to the threat of flooding."

The forecasts will be publicly available via the existing GLoFAS interface

(http://www.globalfloods.eu).

Notes to editors

The European Centre for Medium-Range Weather Forecasts (ECMWF) is an

independent intergovernmental organisation supported by 34 states. ECMWF is

both a research institute and a 24/7 operational service, producing and

disseminating numerical weather predictions to its Member and Co-operating

States as well as licensed users. The organisation was established in 1975 and

now employs around 350 staff from more than 30 countries. ECMWF is based in

Reading, UK.

Copernicus is a European Union Programme aimed at developing European

information services based on satellite Earth observation and in situ

(non-space) data. The Programme is coordinated and managed by the European

Commission. ECMWF operates two of the six Copernicus services on behalf of the

EU: the Copernicus Climate Change Service (C3S) and the Copernicus Atmosphere

Monitoring Service (CAMS). ECMWF is also the computational centre for European

flood awareness and forest fire information systems which are part of the

Copernicus Emergency Management Service (EMS).

The Global Flood Awareness System (GloFAS), jointly developed by the Joint

Research Centre of the European Commission and ECMWF, is independent of

administrative and political boundaries. It couples state-of-the-art weather

forecasts with a hydrological model and with its continental-scale setup it

provides downstream countries with information on upstream river conditions as

well as providing continental and global overviews.

Hilda Carr - Head of Communications

+44-0118-949-9000

pressoffice@ecmwf.int

SOURCE: The European Centre for Medium-Range Weather Forecasts (ECMWF)