Nowcasting tracks of severe convective storms in West Africa from observations of land surface state

Taylor, Christopher M.; Klein, Cornelia; Dione, Cheikh; Parker, Douglas J.; Marsham, John H.; Diop, Cheikh Abdoulahat; Fletcher, Jennifer K.; Chaibou, Abdoul Aziz Saidou; Nafissa, Dignon Bertin; Semeena, V. S.; Cole, Steven J.; Anderson, Seonaid R.

doi:10.1088/1748-9326/ac536d

Cited by 6 publications

(5 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Based on the previous study, Taylor et al . (2022) have developed and shown the potential of using land surface temperature (surface skin temperature) anomalies as soil moisture proxy for nowcasting storms over West Africa.…”

Section: Resultsmentioning

confidence: 99%

“…For instance, Klein and Taylor (2020) found a preference for storms to initiate, intensify and propagate over drier soils (warmer T s ) as compared to the wetter soils. Based on the previous study, Taylor et al (2022) have developed and shown the potential of using land surface temperature (surface skin temperature) anomalies as soil moisture proxy for nowcasting storms over West Africa.…”

Section: Airs Surface Skin and Air Temperaturementioning

confidence: 99%

See 1 more Smart Citation

West Africa's moist convective environment as observed by the Atmospheric InfraRed Sounder (AIRS)

Osei

Ferguson

Quansah

et al. 2023

Intl Journal of Climatology

View full text Add to dashboard Cite

Knowledge of the seasonal positioning of the Intertropical Discontinuity (ITD) is critical to understanding seasonal moist convective processes and associated rainfall over West Africa. This study constitutes a new analysis of the seasonality of moist convection over West Africa, relative to the ITD, based on NASA's Atmospheric Infrared Sounder (AIRS) measurements from 2003 to 2018. Results show that AIRS resolves the seasonal march of the ITD, including its inherent diurnal‐scale variations. AIRS captures the north–south daytime skin temperature dipole around the ITD, with greater relative temperatures to the north, especially during March–August. In the vicinity of the nighttime ITD, AIRS profiles indicate increased instability that is characteristic of nocturnal thunderstorm propagation. For seven Ghana weather stations, we show that AIRS positive moisture and equivalent potential temperature anomalies coincide with observed thunderstorm days. On these thunderstorm days, the mean latitude of the AIRS‐derived ITD is displaced 3°, 0.2°, and 2° north of its DJF, MAM, and SON climatological positions, respectively, and 1.2° south in JJA. Among four common thunderstorm initiation indices considered, the K‐index is determined to be most skillful. The findings of this study contribute to the Global Challenges Research Fund, African Science for Weather Information and Forecasting Techniques project's mission to build local tropical weather forecasting capacity and capabilities in West Africa.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Airs Surface Skin and Air Temperaturementioning

confidence: 99%

West Africa's moist convective environment as observed by the Atmospheric InfraRed Sounder (AIRS)

Osei

Ferguson

Quansah

et al. 2023

Intl Journal of Climatology

View full text Add to dashboard Cite

show abstract

“…The system could be further improved by including additional meteorological information, either observed or forecast. For example, as land surface temperature (LST) has been shown to constrain the development of convection (Klein & Taylor, 2020; Taylor et al ., 2022), including LST in the nowcasting system could lead to improvements in skill. Including further convective structure properties, such as temperature or size, and larger‐scale atmospheric information related to convective initiation, could also lead to improvements.…”

Section: Summary and Discussionmentioning

confidence: 99%

Nowcasting convective activity for the Sahel: A simple probabilistic approach using real‐time and historical satellite data on cloud‐top temperature

Anderson,

Cole,

Klein

et al. 2024

Quart J Royal Meteoro Soc

Self Cite

View full text Add to dashboard Cite

Flash flooding from intense rainfall frequently results in major damage and loss of life across Africa. In the Sahel, automatic prediction and warning systems for these events, driven by Mesoscale Convective Systems (MCSs), are limited, and Numerical Weather Prediction (NWP) forecasts continue to have little skill. The ground observation network is also sparse, and very few operational meteorological radars exist to facilitate conventional nowcasting approaches.Focusing on the western Sahel, we present a novel approach for producing probabilistic nowcasts of convective activity out to 6 h ahead, using the current location of observed convection. Convective parts of the MCS, associated with extreme and heavy precipitation, are identified from 16 years of Meteosat Second Generation thermal‐infrared cloud‐top temperature data, and an offline database of location‐conditioned probabilities calculated. From this database, real‐time nowcasts can be quickly produced with minimal calculation. The nowcasts give the probability of convection occurring within a square neighbourhood surrounding each grid point, accounting for the inherent unpredictability of convection at small scales.Compared to a climatological reference, formal verification approaches show the nowcasts to be skilful at predicting convective activity over the study region, for all times of day and out to the 6‐h lead time considered. The nowcasts are also skilful at capturing extreme 24 h rain gauge accumulations over Dakar, Senegal. The nowcast skill peaks in the afternoon, with a minimum in the evening. We find that the optimum neighbourhood size varies with lead time, from 10 km at the nowcast origin to around 100 km at a 6‐h lead time.This simple and skilful nowcasting method could be highly valuable for operational warnings across West Africa and other regions with long‐lived thunderstorms, and help to reduce the impacts from heavy rainfall and flooding.This article is protected by copyright. All rights reserved.

show abstract

“…For a full list of diagnostic definitions see Clarke and Ansah (2022). Land surface temperature products for Sahel (Taylor et al 2022).…”

Section: Data Availability Statementmentioning

confidence: 99%

Tropical Africa’s First Testbed for High-Impact Weather Forecasting and Nowcasting

Fletcher

Diop

Adefisan

et al. 2023

Bulletin of the American Meteorological Society

View full text Add to dashboard Cite

Testbeds have become integral to advancing the transfer of knowledge and capabilities from research to operational weather forecasting in many parts of the world. The first high-impact weather testbed in tropical Africa was recently carried out through the African SWIFT program, with participation from researchers and forecasters from Senegal, Ghana, Nigeria, Kenya, the United Kingdom, and international and pan-African organizations. The testbed aims were to trial new forecasting and nowcasting products with operational forecasters, to inform future research, and to act as a template for future testbeds in the tropics. The African SWIFT testbed integrated users and researchers throughout the process to facilitate development of impact-based forecasting methods and new research ideas driven both by operations and user input. The new products are primarily satellite-based nowcasting systems and ensemble forecasts at global and regional convection-permitting scales. Neither of these was used operationally in the participating African countries prior to the testbed. The testbed received constructive, positive feedback via intense user interaction including fishery, agriculture, aviation, and electricity sectors. After the testbed, a final set of recommended standard operating procedures for satellite-based nowcasting in tropical Africa have been produced. The testbed brought the attention of funding agencies and organizational directors to the immediate benefit of improved forecasts. Delivering the testbed strengthened the partnership between each country’s participating university and weather forecasting agency and internationally, which is key to ensuring the longevity of the testbed outcomes.

show abstract

Nowcasting tracks of severe convective storms in West Africa from observations of land surface state

Cited by 6 publications

References 50 publications

West Africa's moist convective environment as observed by the Atmospheric InfraRed Sounder (AIRS)

West Africa's moist convective environment as observed by the Atmospheric InfraRed Sounder (AIRS)

Nowcasting convective activity for the Sahel: A simple probabilistic approach using real‐time and historical satellite data on cloud‐top temperature

Tropical Africa’s First Testbed for High-Impact Weather Forecasting and Nowcasting

Contact Info

Product

Resources

About