Climate Prediction

Climate Prediction & Early Warning

Skillful climate forecasting and timely early warning forms the foundation of any operational climate centre. The IGAD Climate Prediction and Applications Centre (ICPAC), as a Regional Climate Centre provides medium range and extended climate forecasts that are required by Intergovernmental Authority on Development (IGAD), the National Meteorological and Hydrological Services (NMHSs), and other national, regional and international partners. The Instituttuion uses two techniques to provide climate outlooks namely dynamical and statistical forecast approaches; with the latter being derived from WMO Global Producing Centers amongst others. The seasonal climate forecasts is a blend of the two techniques. The dynamical climate modeling methods requires enormous computing power and skilled human capacity. The main priority of the section is two folds; improvement of computing capacity for ICPAC and memeber countries, human resources and development of new forecasting tools and products required for sector specific applications.

Statistical Climate Forecasting

The statistical forecasting methods are based on empirical relationships between rainfall over specific parts of the GHA and some global / regional/ local climate system indices. The major climate system indices that are operationally used at ICPAC include evolution of monsoons, medium and upper level winds, Madden-Julian Oscillation (MJO), Quasi Biennial Oscillation (QBO), El Niño Southern Oscillation, Indian Ocean dipole (IOD), tropical cyclones, sea surface temperature gradients among many others that have been derived from general circulation. Statistical downscaling of the global model outputs like GPCs are done using tools like CPT. ICPAC also runs Weather Research and Forecasting Model (WRF) for medium range forecasts; with Initial and Boundary conditions derived from GFS model. The forecasts products are mainly Tempearture, Precipitation and surface winds.

The statistical methods, however, cannot fully account for some of the rainfall variability. A lot of efforts must therefore be made to improve the skills of the forecasting systems. At the moment ICPAC is collaborating with a number of partners such as IRI, NCEP/CPC, UKMO, and KMA, among others to address climate forecasting and early warning challenges in the region.

The activities of the unit during the past eleven years( 2005-2015) have been:

  • Documentation of the methods and associated applications.
  • Provide forecasts on rainfall onset, cessation and distribution of dry/wet spells and temperature.
  • Continuous verification of the forecasting products to assess the skill of the forecasts disseminated to the users.
  • Diagnostic research to improve the forecasting products for various time scales.
  • Develop pilot projects to assess and communicate successful use of forecasts.
  • Improvement of statistical techniques on the downscaling of forecasting products to meet user requirements.
  • Ensure user feedback is incorporated into forecast developments.
  • Continue to improve the capacity of the member states on statistical and other new and emerging climate forecasting technologies.
  • Enhance collaboration with other relevant regional and international centres engaged in climate forecasting and application services.
  • Use of new tools and techniques like FIT, GIS, Geo-COF amongst others to improve seasonal forecasting.
  • Use of Geo-Clim tool to grid station and satellite data.

Dynamical Climate Forecasting

The dynamical climate modelling methods used at ICPAC provide the evolutionary spatial and temporal evolutionary dynamics of weather and climate evolutions over the GHA region. Currently, ICPAC runs WRF model for medium range weather forecasts, PRECIS model for climate chnage and scenario development; and is in the process of setting up a Regional Spectral Model (RSM) for downscaling seasonal forecasts. The RSM model computation principle lies on the Fast Fourier Transform (FFT) technique which is its strength over grid point model techniques. The Initial and Boundary conditions are derived from NCEP GSM Reanalysis. The ultimate objective of the unit is to operationalize the running of the Regional Climate Models for downscaling of weather and climate at different time-scales. The Insituion is currently in the process of acquiring high perfomance computing cluster for modeling.

Applications

Future Plans to enhance NWP at ICPAC and NMHS
  • Adoption and operationalization of RSM for downscaling seasonal forecasts.
  • Aquisition of computing facilities with higher computing power.
  • Training of national experts within the GHA on seasonal dynamical forecasting procedures.
  • Assist NMHS to source for software and hardware facilities for basic modelling and programming techniques.
Enhancing Medium Range NWP at ICPAC in Support of 10 day bulletins and NMHS
  • Set up and update continuously the operational databases necessary for running models.
  • Verify and use NWP products from other centers: COLA, IRI, KMA and others operationally at ICPAC.
  • Undertake capacity building/training on medium range NWP and it’s operational challenges.
Climate Modelling and Downscaling for seasonal Forecasts s at ICPAC
  • Operational use of dynamical downscaling with the RSM and WRF models for seasonal forecasting over GHA.
  • Operational use of Model Output Statistics (MOS) of the global model as statistical downscaling appproach for seasonal forecasts.
  • Creation and analysis of the GSM/RSM and WRF model database for seasonal and evaluation of the skill of the models.
  • Continuation of regional capacity building in dynamical climate modeling.
  • Acquisition of High Pefomance Computing(HPC) for clustering technology and parallel computations.
  • Generation of seasonal forecasts operational at ICPAC for GHACOF processess.