Journal of Meteorology and Climate Science

Future projections of temperature extremes and socioeconomic impacts in the Kaduna River Basin under different climate scenarios

Gloria C. Okafor — 2026-07-23

Climate extremes threaten food security and socioeconomic activities in West Africa. This study examines the projected (2036 - 2065) temperature trends and extremes in the Kaduna River Basin (KRB) under climate scenarios RCP4.5 and RCP8.5, revealing significant increases in mean and extreme temperatures by the 2050s. Findings indicate projected rise in mean annual temperatures of 1.87°C (RCP4.5) and 2.2°C (RCP8.5) compared to historical (1981 - 2010) averages, with more pronounced warming in the dry season and early cropping period. This warming trend aligns with regional studies, highlighting increased vulnerability to heat stress, water scarcity, and crop yield reductions. Diurnal temperature ranges are also expected to expand during the wet season and contract during the dry season. Spatial variations indicate heightened warming in the basin’s upstream areas, particularly during the wet season, while temperature extremes such as warm days and nights are set to increase basin-wide. The study underscores potential socioeconomic impacts, including intensified heat stress, productivity declines in agriculture and construction, elevated energy demands, and increased health risks. To address these challenges, the study advocates for climate-resilient policies, including early warning systems, enhanced climate data infrastructure, and diversified livelihoods, to bolster adaptive capacity and ensure sustainable development across the KRB.

Empirical confirmation and review of causes and effects of dry spell in southwest Nigeria: A case study of Ibadan, Oyo State

OlatunjiDavid, Ayeni — 2026-07-23

Dynamic changes in weather pattern have responsibility in affecting the climate of southwest Nigeria. As a result, the impacts was felt in farming calendar, agricultural yield and water resources management despite the suitable geographical location, of the study area. In this study, review and empirical analysis of dry spell using 10 years (2014 - 2023) daily rainfall data collected from Forestry Research Institute of Nigeria Meteorological weather station. Four dry spell indices: Frequency Dry Spell (FDS), Total Dry Spell (TDS), Maximum Dry Spell (MxDS), Mean Dry Spell (MDS), were examined to analyze the seasonal rainfall variables such as onset, cessation, total and distribution of rainfall. The results analyzed in descriptive form showed the occurrence of dry spell in all the month. The average dry spell ranges between 4.8 and 10.4 days. The average expected rainy days (90 days) was higher than the average observed (72.4 days) rainy days. The observed rainy days across the years, ranges between 58 days and 91 days. The months that supposed to be the onset of rainy season (March) had very high dry spell of 10.2. There were great deviations in the monthly average expected rainy days from observed rainy days. Unevenly distribution of rainfall was revealed through variation in rainy days across the years and intra-year. Average FDS ranges between 2.6 to 3.6 in the wet season. Coefficient of variation (CV) results confirmed variability in dry spells and rainy days in two periods. The results generally confirmed the occurrence of dry spell in southwest Nigeria. The information is valuable for the planning, organization and execution of agricultural activities and water resources management in the region.

Analysis of land surface temperature changes in the hinterland of Southern Ondo

Cosmas Adewebi — 2026-07-23

This study investigated the pattern of changes in the land surface temperature and land use land cover of the Hinterland of Southern Ondo State between 1984 and 2023, the major factor influencing LST changes was determined and the relationship between the land surface temperature and the structure types of Peri-Urban settlement of Ore, Okitipupa and Irele was analyzed. The results show that the mean LST value has gone from 21.8°c in 1984 to 28.89°c in 2023. The land use land cover analysis shows that 8% of the Hinterland was covered by the Built-up area in 1984 and has expanded to cover 11% of the Hinterland in 2023. The correlation analysis to identify the factor driving LST changes shows a unit increase in the NDBI in 1984, 1999, and 2023 driven increase in the LST values and a unit increase in the NDVI all through the years showing a decrease in LST values. The analysis of the relationship between the structure types of the Peri-Urban settlements and LST distribution using the Local Climate Zone approach shows the Compact Low-Rise and the Bush and Scrub zone have higher mean LST values; 35°c and 35.3°c in the Bush and Shrub zone and the Compact Low-Rise zone respectively in Irele, 36.3°c and 34.7°c in the Bush and Shrub zone and the Compact Low-Rise zone respectively in Ore, in Okitipupa, the mean LST value in the Bush and Scrub zone is 35.2°c and 34.8°c in the Compact Low-Rise zone. The results demonstrate that every land use change drives changes in the pattern of the land surface temperature over the Hinterland.

Characterizing urban green infrastructure and its climatic interactions in Akure: A GIS and remote sensing approach

Oluwadunsin Grace Elegba — 2026-07-23

Urban green infrastructure (UGI) plays a vital role in moderating microclimates, yet its dynamics in rapidly urbanizing cities remain underexplored. This study examines the spatial distribution and climatic interactions of UGI in Akure, Nigeria, from 1984 to 2023 using GIS and remote sensing techniques. NDVI was used to assess vegetation cover changes, while ERA5 meteorological data provided insights into temperature, relative humidity, and precipitation trends. Results reveal a 94% reduction in high-density vegetation and a 90% increase in built-up areas, contributing to rising temperatures (up to 26.35°C in 2023) and declining relative humidity (70.66%–76.77%). Precipitation remained stable but showed slight declines in urban areas. The findings underscore the critical role of UGI in mitigating urban heat islands and sustaining atmospheric moisture. The study calls for integrated urban planning policies to enhance
green space preservation and promote sustainable development in Akure and similar cities.

Rainfall variability study of Central Abeokuta metropolis using remote sensing data

G.C. Ufoegbune — 2026-07-23

Rainfall variance refers to the statistical measure of how much individual rain events deviate from the average rainfall amount, indicating the spread or dispersion of rainfall data. Rainfall variability impacts the soil's water availability to crops, causing reduced crop production. This study evaluated the temporal and spatial distribution of rainfall in the Central Abeokuta using CHIRPS remote sensing data. CHIRPS dataset of 30 years for 3 parts of Central Abeokuta (Kuto, Lafenwa, and Onikolobo) was used. The rainfall patterns of the 3 communities were compared in terms annual, seasonal and daily differences. The study adopted a descriptive statistical approach. The results showed that the pattern of rainfall for the communities were similar, following the general trend of 2 rainfall peaks and 2 dry periods annually. In terms of micro-meteorology, there were differences in daily, monthly, seasonally and annual rainfalls of those communities. The study thus revealed that there were actual variability in rainfall over small zones, and that micro-meteorological differences existed.

Rainfall variability analysis of North-east Abeokuta using remote sensing data

G.C. Ufoegbun — 2026-07-23

The instability of rainfall occurrence yearly or spatially above or below a long- term mean value over a particular period is usually taken as rainfall variability. In many settlements, the spatial distribution of rainfall is great that it starts to give the dwellers of such settlements cause for concern. This issue is often compounded by the fact that these settlements usually have just one or two rain gauges for their service This study focused on assessing the variability of rainfall over Abeokuta North-east applying remote sensing data. CHIRPS dataset of 30 years for 3 parts of Abeokuta North-east (Adatan, Obantoko and Alababa) was used. The rainfall patterns of the 3 communities were compared in terms annual, seasonal and daily differences. The study adopted a descriptive statistical approach. The results showed that the pattern of rainfall for the communities were similar, following the general trend of 2 rainfall peaks and 2 dry periods annually. In terms of micro-meteorology, there were differences in daily, monthly, seasonally and annual rainfalls of those communities. The study thus revealed that there were actual variability in rainfall over small zones, and that micro-meteorological differences existed.

Community responses to climate change: Impact on water quality, human health and economy in parts of Abeokuta, Nigeria

B.O. Layi-Adigun — 2026-07-23

Climate change is a growing problem worldwide, especially in developing countries. This study examined the perception of some communities in Abeokuta, Nigeria, in response to climate change impact to water quality, human health, and the local economy. The research focuses on four areas: Ijaye, Lafenwa, Amolaso, and Kuto, using a combination of maps, surveys, interviews, and existing data to understand the situation. Self administered questionaires were used to solicit the views of the residents in the study area. The study identified the main climate challenges these communities face, such as flooding, extreme temperatures, and changes in rainfall patterns. These issues have led to poorer water quality, with more pollution and less safe drinking water, which in turn has increased the risk of water-related diseases. The result of the study also indicatied the rise in health problems like malaria, cholera, and respiratory issues, which were becoming more common as the climate changes. On the economic side, climate change was making poverty worse and disrupting jobs, especially in farming, which depends on stable weather. The results also examined the adaptation of these communities, from traditional methods to newer ways, but often are bedeviled by insufficient infrastructure improvements. It found that while people were trying to cope, their efforts were often not enough, as they lack proper planning, coordination, and funding. The research concluded that there is an urgent need for better climate policies, stronger infrastructure, and greater community awareness to help these communities become more resilient to climate change. The findings emphasize the importance of taking action now to protect public health, livelihoods, and the environment in Abeokuta.

Precipitation trends and variability in Delta State, Nigeria (1990-2020): Implications for water management and disaster risk reduction

Gloria C. Okafor — 2026-07-23

This study examines the annual and spatial variation in precipitation over Delta State, Nigeria, from 1990 to 2020, analyzing variability, spatial patterns, and the implications of changing rainfall dynamics. A decreasing trend in annual precipitation was identified, with notable fluctuations such as high rainfall in 2009 and low rainfall in 2001. The coefficient of variation (69%) indicated significant variability in rainfall across different months, with the southern coastal areas experiencing more pronounced rainfall and higher flood risks. The spatial disparity in rainfall patterns across the state, likely influenced by topography, land use, and oceanic air masses, was also highlighted. Seasonal fluctuations were evident, with July and January having the highest and lowest mean rainfall, respectively. While precipitation levels were not statistically significant, the study underscored the region’s vulnerability to both droughts and floods, especially in the wet season. The Standardized Precipitation Index (SPI) further indicated dry spells and wet conditions, with the most prolonged drought occurring between 2013 and 2020. These findings underscore the importance of adaptive strategies in water resource management, flood prevention, and disaster risk reduction. The research emphasizes the need for strategic planning to address the challenges posed by changing precipitation patterns in Delta State, especially in agriculture, infrastructure, and socioeconomic activities.

Blackpod disease and its threat to cocoa yields in southwestern Nigeria: A case study of the cocoa research institute of Nigeria, ibadan

B. M. Dada — 2026-07-23

Among the key agricultural commodities in Nigeria and the Southwest, cocoa is very important, contributing to the local economy and household livelihoods. In several ways, however, its productivity is increasingly threatened by black pod disease due to various Phytophthora species, especially P. palmivora and P. megakarya. The incidence of black pod disease was related to temperature, rainfall, and relative humidity over a period of 30 years from 1986 to 2015 at the Cocoa Research Institute of Nigeria, Ibadan. Climate trends were analyzed based on statistical methods, box plots and correlations that show the description of trends in relation to disease prevalence. These results indicated that high rainfall, high humidity, and an increase in black pod diseases are related, hence the urgent need for climate-adaptive agricultural practices. The paper therefore forms a foundation for developing sustainable mitigation strategies that target climate-related disease risk factors with a view to ensuring resilience in cocoa production in Nigeria.

Urban farming and climate variability in Oyo Town, Nigeria

Elisha Ademola Adeleke — 2026-07-23

Climate in urban areas is synonymous to high temperature and affects agricultural productivity in a relative terms. This study examined how variability in urban climate affects agricultural production in urban area of Oyo town. Both primary and secondary data were used for this study. The primary data were collected through questionnaire administration while secondary data (climate variables) were collected from Nigeria Meteorological Agency. The data were analyzed using both inferential (correlation, and regression analysis) and descriptive (mean, standard deviation, tables, and charts) statistics. The study showed that, the mean lowest temperature in the area was 22.5 oC, the mean rainfall was 126.44 mm, the mean wind speed was 5.09 m/s, the mean relative humidity was 79.7%, and the mean maximum temperature was 31.7 oC. The results also showed that groundnut yield decreased by 13.4 per hectare on average, the cowpea yield decreased by 12.95 per hectare on average, while tomato yield increased by 22.46 per hectare on average. In addition, there was an inverse relationship between (-0.029) wind, (-0.063) rainfall, and (-0.078) rainfall with groundnut, cowpea, and tomato. The climatic variables accounted for increase of 13.4% of the yield of tomatoes, 12% of cowpeas, and 1% of groundnuts. The study concluded that local climate significantly affects the productivity of the selected crops. The study however recommended that urban farmers need to save water during rainy season for irrigation agriculture in the dry season. Hence, Nigerian Meteorological Agency and other agencies should provide farmers with adequate weather information for sustainable urban farming.

Determination of rainfall onset, cessation and length of growing period for crop planning in South West Nigeria.

Kolawole Oladipo Ayoola — 2026-07-23

Rainfed agriculture is predominantly practiced in the tropics, therefore, this research determined rainfall onset, cessation and length of growing period for crop planning in South West Nigeria. Twenty-eight-year (1990 to 2017) daily rainfall data of Abeokuta, Akure, Ibadan, Lagos and Oshogbo were sourced from the Nigerian meteorological agency and analysed using the Walter (1967) model to determine the length of growing period while FAO (1986) crop growing cycle showed the number of growing periods for crops domiciled in each station. Results showed the average onset, cessation and length of growing period recorded for each location: Abeokuta (28th March, 2nd October and 193 days), Akure, (11th April, 6th November and 225 days), Ibadan (29th March, 16th November and 200 days), Lagos (27th March, 4th November and 218 days) and Oshogbo (21st March, 15th October and 202 days). Hence, most crops domiciled in South West Nigeria can be grown just once within the rainy season except for cowpea, rice, maize and groundnut that can be grown twice in all selected stations. Akure and Lagos both with longer length of growing season were capable of growing other crops like potato and groundnut twice in a season. Hence, this work will help farmers in South West Nigeria to plan their cropping pattern and avoid crop failure.

Potentials and challenges of green energy as mitigation strategies to climate change a review of literature

Y. Bello — 2026-07-23

Green energy is the kind of renewable energy generated from natural resources that cause no harm to the environment through the release of greenhouse gases. The green sources of energy were; sunlight, wind, tides, hydroelectric, nuclear, thermal, algae, and geothermal heat. The potentials and challenges of green energy were reviewed. The literature reviewed revealed that hydroelectric, sunlight, and geothermal have the highest potential of generating green energy and mitigating climate change directly through a reduction in greenhouse gas emissions. The challenges faced by hydroelectric generation were a decline in rainfall and, high evaporation rate. Solar energy source faced the challenge of government policies and lack of enough land surface to install panels. Wind energy was a threat by the local landscape as well as changes in the landuse, undispatchable nature of wind, the difficulty of forecasting and the impossibility of storing and several technical, environmental, financial, political, and social challenges. Climate change affects the availability and productivity of geothermal resources through; changes in rainfall patterns and prolonged droughts which affect groundwater levels and slow down recharge rates of wells which affect water levels in shallow geothermally heated aquifers. It also affects the efficiency of geothermal power plants, causing reductions in electricity generation. This study concludes that green energy has the potential to mitigate climate change, but the menace of the changing climate and government is seriously militating against its realization. The findings recommend Hybrid energy systems (wind-solar) because of their complementary nature.

Effect of abattoir waste on groundwater quality in Abeokuta North and South local government area, Ogun State Nigeria

A.A. Adekitan — 2026-07-23

This study explores the impact of abattoir waste on groundwater quality in Abeokuta North and South, Southwest Nigeria. The primary goal of this study is to assess the contamination of groundwater due to improper disposal of abattoir waste and its implications for public health and environmental sustainability. Groundwater serves as a key source of drinking water in these regions, and contamination from abattoir waste poses significant health risks, particularly for communities relying on these water sources. The issue stems from inadequate waste management at abattoirs, leading to harmful substances like heavy metals, chemicals, and microbial pathogens leaching into groundwater. This contamination poses public health threats, including waterborne diseases and long-term effects from heavy metal exposure. To evaluate the extent of contamination, groundwater samples were collected from wells near abattoirs and compared with a control sample from an unaffected area. These samples were analysed for physicochemical properties (pH, temperature, electrical conductivity), chemical properties (nitrate, phosphate, salinity), heavy metals (sodium, lead), and microbial contaminants (Total Bacterial Count, Total Coliform Count, E. coli), using World Health Organization (WHO) water quality standards as a reference. The findings showed that while pH, temperature, and some chemical parameters were within WHO limits, lead concentrations exceeded permissible levels in some samples, indicating heavy metal contamination. Microbial analysis revealed excessive Total Bacterial and Coliform Counts, with thermo-tolerant E. coli detected, indicating severe microbial contamination. The groundwater near abattoirs showed significant contamination, particularly from heavy metals and microbial pathogens, posing health risks to local communities. The study recommends improved abattoir waste management, regular groundwater quality monitoring, and public health awareness initiatives to address these risks and promote environmental sustainability.

Impact of cement production on surface water quality in Ewekoro, Ogun State, South-western Nigeria.

A.A. Adekitan — 2026-07-23

Industrial activities are one of the major sources of surface water pollution. This study assessed the impacts of cement production from industry on surface water. Four (4) water samples were obtained from Akinbo and Alaguntan rivers at the upstream and downstream sections. The various parameters analyzed include: Physical, chemical, heavy metal and Microbial parameters. The following results were obtained for all the collected samples.pH (6.97 - 7.32), temperature(26.90 - 29.30°C), Electrical Conductivity (240 - 320 μS/cm), Total Dissolved Solids (99.90 - 129.90 mg/L, Biological Oxygen Demand (0.35- 1.70mg/L), Dissolved Oxygen(5.0 - 5.9mg/L), Total Alkalinity(7.80 -15.60mg/L), TotalHardness (236.00 -708.00 mg/L),Calcium (126.00-164.00 mg/L), Chloride (59.00-118.00 mg/L),Sulphate (76.8-109.2mg/L), (Phosphate14.2 -20.2mg/L). Potassium (5.00-7.00mg/L), (Sodium10.00 -15.50 mg/L), Magnesium (110 -544mg/L). TBC (8.70- 13.40cfu/ml), TCC (39.00 -75.00 cfu/100ml), TEC (15.00 - 39.00 cfu/100ml). Result of the heavy metal parameters are: (Iron 0.32 -0.57 mg/L), (Copper 0.08 -0.13mg/L), Zinc(0.47 -0.79mg/L, Lead (0.32 -0.82 mg/L), (Chromium 0.31 -0.47 mg/L). The results were compared with the World Health Organization (WHO, 2017), guidelines for drinking water. The heavy metals parameters such as Iron, Lead and Chromium were higher than the WHO guideline for drinking water given as of 0.3 mg/L, 0.01 mg/L, and 0.05 mg/L respectively. Therefore itcan beconcluded that the wateris unfit for domesticuses, and needs to be treated before use.

Effect of screenhouse micro-climate and planting media on the performance of tomato (Lycopersicon esculentum mill) nurseries in Ofada, Nigeria

A.A. Oni-Orisan — 2026-07-23

The study evaluated the effects of screenhouse microclimate and growing media on the performance of tomato seedlings. The experiment was a 2 x 4 factorial design fitted into a Completely Randomized Design with three replicates where varieties were assigned to the main plots and the media to the subplots. It include two varieties of tomato, Eva™ and Nemonetta™ and four growing media, local peat moss, cocopeat mixed with perlite, compost dresser, and organic soil. The experiment was carried out in three growing microclimates, a screenhouse without crops (nursery screenhouse), screenhouse with crops (general screenhouse), and open field. The experiment was conducted during the dry season (December) and the wet season (April) at the demonstration site of Dizengoff Nigeria Limited, Ofada, Obafemi-Owode LGA, Ogun State, Nigeria. The parameters measured were emergence, plant height and number of leaves. The meteorological indices of each micro-climate taken were relative humidity, minimum and maximum temperatures. Fertigation parameters (pH, total dissolved solid, electrical conductivity, temperature and fertigation volume), were also measured and kept constant all through the experiment. The data obtained were subjected to analysis of variance and Person Product Moment correlation analysis. The results from the study showed that nursery screenhouse microclimate had the most significant (p<0.05) emergence (91.7%, 88.5% and 55.2%) using local peat moss across the 3 weeks of experiment, respectively. However, general screenhouse micro-climate had the tallest emerging seedlings (2.39 cm, 4.76 cm and 8.10 cm heights) using the mix of cocopeat and perlite at within the 3 weeks period respectively.

Impact of temperature and rainfall fluctuations on the growth stages of wheat (Triticum aestivum l.) in the savannah region: An agro-meteorological perspective

R. M. Olanrewaju — 2026-07-23

Agricultural activities most especially crop production is climate determined in all ecological zones of Nigeria. Wheat crop production in the savannah ecological zone of Nigeria faces significant challenges due to climate variability, particularly temperature and rainfall fluctuations. Crop productivity is strongly influenced by these climatic factors, as they affect all stages of crop growth and development and hence yield. This study investigates the impact of temperature and rainfall variability on the growth stages of wheat (Triticum aestivum L.) in the savannah region of Nigeria. Ten years climatic data from the Nigerian Meteorological Agency and wheat yield data from the Lake Chad Research Institute were analyzed. Pearson Moment Correlation and Multiple Regression analysis were employed to assess the relationship between wheat yield and selected climatic variables. Results revealed that maximum temperature (r = 9.8) was positively correlated with wheat yield, though not statistically significant, while minimum temperature (r = -25.1) and rainfall (r = -45.7) exhibited negative correlations, with rainfall being statistically significant at p< 0.05. The coefficient of determination (R²) indicated that 78.2% of the variation in wheat yield was explained by these climatic variables. The study concludes that fluctuations in temperature and rainfall significantly impact wheat growth, especially during critical stages such as germination and flowering. To mitigate these effects, the adoption of climate-smart agricultural practices, is recommended.

Potential of environmental conditions to predict meningitis epidemics in Burkina Faso, Mali, Niger and Nigeria using artificial intelligence models

Diarra Diouf — 2026-07-23

Bacterial meningitis is a major public health and policy challenge. Its rapid transmission usually leads to widespread outbreaks if not managed effectively, suggesting a comprehensive preparedness based on predictive output to ensure and mitigate outbreaks and its catastrophic effects. This paper explores the potential of various machine learning (ML) models including: linear models such as Ridge, Lasso, ElasticNet; tree-based ensemble models such as Random Forest, Gradient Boosting, AdaBoost, CatBoost and XGBoost; and a deep learning model such as LSTM to predict the incidence of bacterial meningitis in Burkina Faso, Mali, Niger and Nigeria. Weekly datasets between January and June from 2006 to 2020, including 390 cases of bacterial meningitis and surface-level environmental variables such as aerosols (aerosol optical depth and particulate matter with a diameter of 10 microns or less [PM10]), wind components, temperature and relative humidity. Vaccine effects were also considered in the development of the models. Finally, an explanatory approach based on the SHapley Additive exPlanations technique was also used to attribute the contribution of each feature to the model output.The results show that in Burkina Faso (Fig. 3.a), the best performing model is Gradient Boosting with R² = 0.541 and CatBoost where R² is 0.537. In Nigeria (b), all models performed relatively poorly. Best: Gradient Boosting (R² = 0.271), while in Niger (c) Ridge Regression (R² = 0.400) is the best performing model. Mali (d) has a low R², the best being ElasticNet (R² = 0.249).

The health impacts of heatwaves in a warming climate: A case study of Ouagadougou, Burkina Faso

Zouma Emeline Nadege Millogo — 2026-07-23

In the context of ongoing climate change, the frequency, duration, and intensity of heatwaves have risen significantly, particularly in vulnerable regions like Burkina Faso. This study investigates the relationship between heatwaves and health in Ouagadougou by analysing climatic and mortality data from 2015 to 2022. Daily temperature and humidity data from the Burkina Faso Meteorological Agency, were used to compute heatwave indices (heatwave number (HWN), heatwave frequency (HWF), and heatwave duration (HWD)) based on the Tn90, and Tx90, as well as Temperature Humidity Index (THI). Time series analysis was performed using Auto Regressive Integrated Moving Average (ARIMA) models to identify trends, forecast heatwave occurrences, and assess their potential health impacts. Results indicate a weak but positive correlation between THI and mortality (r = 0.272, R² = 0.074), suggesting that cumulative heat stress may influence health outcomes more than isolated heatwave events. In contrast, the correlation between heatwave frequency and mortality was negligible (r = 0.11), potentially due to adaptive behaviors, limited health data, or incorrect classification of heat-related deaths. The ARIMA model revealed seasonal patterns in mortality, with peaks often aligning with periods of increased heatwave activity. Forecasts for the next three years suggest a stable but persistent health risk. These findings highlight the urgent need for improved public health monitoring, early warning systems, and urban adaptation strategies. Addressing these challenges is essential for achieving Sustainable Development Goals related to health (SDG-3), poverty reduction (SDG-1), and climate action (SDG-13).

Impact of climate indices on thunderstorm variability in Ghana

Robert A. Akum — 2026-07-23

Thunderstorms contribute to the majority of rainfall in West Africa. This rainfall is vital to many rainfall-dependent sectors in Ghana. Therefore, a sound understanding of the drivers of thunderstorms is required. This study examines how global teleconnections drive thunderstorm variability, using the monthly thunderstorm frequency data from 22 synoptic stations in Ghana and the LightGBM regression model. Using the LightGBM regressor and climate indices as features to model monthly thunderstorm frequencies, climate indices drive thunderstorm variability in Ghana's northern and coastal zones more than those in the middle zone. Using recursive feature elimination (RFE), the following climate indices have been found in this study to be the most important drivers of thunderstorms in Ghana: Niño 3, Niño 1+2, Niño 4, Multi-variate ENSO Index (MEI), Western Hemisphere Warm Pool (WHWP), Atlantic Meridional Mode (AMM), and Atlantic Multidecadal Oscillation (AMO). Partial dependence plots (PDPs) and Shapley additive plots (SHAP) were applied to understand further how these climate indices drive thunderstorm variability in Ghana. Higher values of WHWP favour thunderstorm occurrence in the northern zone but reduce thunderstorm occurrence over the middle and coastal zones. Also, higher values of ENSO indices have been observed to suppress thunderstorm occurrence, except the Niño 3 index. These findings highlight the dominant role of WHWP and ENSO indices in modulating thunderstorm activity, with zone-specific impacts across Ghana. The study is the first to apply LightGBM regression and PDP and SHAP-based interpretation to large-scale drivers of thunderstorm variability in the region, offering a new scientific basis for understanding thunderstorm variability and supporting the development of data-driven early warning systems.

Assessing the performance of predictors in WARCOF/PRESASS forecasting approach for the seasonal onset prediction over Sahelian West Africa

Aissatou Sitta — 2026-07-23

In the context of increasing climate change and variability, reliable seasonal forecasts play critical role in agricultural planning. Recurring droughts, erratic rainfall, and limited adaptive capacity in the Sahel have highlighted also the need for timely and usable climate information to enhance resilience among smallholder farmers. The West African Regional Climate Outlook Forums (WARCOF or PRESASS in French) forecasting system, predicts annually the rainy season key parameters (season cumulative rainfall, onset date, cessation date and length of dry spells). However, records often show significant percentage of forecast mismatching with observation. Thus, it urges to evaluate the performance and practical relevance of the WARCOF/PRESASS approach that has been used since 2011 for season agroclimatic characteristics prediction. This study aimed to assess the performance of predictors used and skill of the forecasting system regarding onset date prediction. Canonical Correlations Analysis through cross-validation and quantitative forecast verification techniques (such as reliability diagrams, ROC curves, and AUC) were used to analyze historical forecasts against observed data from 1991 to 2023. The Climate Predictability Tool (CPT) was applied for statistical modelling using sea surface temperature (SST) anomalies, precipitation hindcasts. Key findings indicate that in the WARCOF/PRESASS approach, onset forecasts demonstrated reasonable skill, particularly when using precipitation hindcasts (e.g., NASA and CFSv2) as predictors. The study concludes that enhancing the PRESASS forecasting system requires scientific recalibration using high-performing predictors and user-oriented communication strategies.