Assessement of selected global models in short range forecasting over West Africa: case study of Senegal
Severe weather events in West Africa are associated mainly with meso-scale thunderstorms and squall lines. Forecasting such severe weather to reduce the risk of hazards is one of the challenges faced by many met services. However, the recent progress in the area of numerical weather prediction has enabled some countries to forecast these events in a better way.
Due to lack of capacity, many of the West African countries were not able to use numerical weather prediction systems effectively in their day to day forecasting activities. The CPC/African Desk has been playing big role in building the capacities of the African Meteorological Services. Apart from the regular training activities organized by the Desk, it also hosts useful weather and climate information and products on a dedicated website.
Numerical weather prediction products require verifications in time and space before they are factored into decision making activities. In this work, attempt was made to perform a diagnostic and prognostic analysis with respect to three heavy rainfall events that occurred across Senegal and the neighboring areas during August 2011. We report the results of various verification statistics. The report also contains inter-comparison studies using selected Global models (ECWMF, GFS, UKMET) and attempts to evaluate the strengths and weaknesses of each model with respect to the three rainfall events.
In general, the results of this study show that the deterministic models were able to capture the patterns of the West African Monsoon with respect to the GDAS analysis. In addition, the skill scores for probabilistic rainfall forecasts (10mm and 20mm threshold values) indicated significantly high values (RPSS as high as 0.5 and BSS as high as 0.7) of rainfall mainly for the 10mm and 20mm probability forecasts. Thus, the results of this preliminary work indicate the importance of the use of ensemble forecast system in West Africa.
Notes: Supervisor: Endalkachew Bekele - If you wish to download the full text, please contact library(at)wmo.int (Please replace (at) by @).
Format: Digital (Available online for logged-in users) (ill., charts, maps)