Ferguson (2026) Do wet or dry soils trigger thunderstorms? It depends on how the wind blows

Identification

• Journal: Nature
• Year: 2026
• Date: 2026-03-04
• Authors: Craig R. Ferguson
• DOI: 10.1038/d41586-026-00376-4

Research Groups

• Earth Science Division, NASA (author of this News & Views article)
• European Space Agency (ESA) (provider of satellite data for the discussed study)
• European Centre for Medium-Range Weather Forecasts (ECMWF) (provider of reanalysis data for the discussed study)

Short Summary

This News & Views article discusses how the interaction between soil moisture and vertical wind shear significantly influences thunderstorm initiation, enabling more precise short-term forecasting of intense storms.

Objective

• To understand how wind conditions modulate the relationship between soil moisture and thunderstorm initiation, thereby improving the accuracy of short-timescale thunderstorm forecasting.

Study Configuration

• Spatial Scale: Sub-Saharan Africa (regional); thunderstorm initiation pinpointed within 10–40 kilometers; analysis within large 500–1,000 square kilometer regions.
• Temporal Scale: Observational data collected over 21 years; improved prediction lead times of 15–60 minutes for thunderstorm initiation.

Methodology and Data

• Models used: ECMWF Reanalysis v5 (ERA5) for wind shear data (combines numerical models with observational data).
• Data sources:
  • High-resolution cloud-top temperature data from ESA’s Meteosat Second Generation satellites.
  • Soil moisture data from ASCAT instruments on ESA’s Meteorological Operational satellites.
  • Vertical wind shear data (between 100 and 3,600 meters above ground) from ECMWF’s ERA5 reanalysis.
  • Supplementary satellite-based data on precipitation, surface temperature, and lightning.

Main Results

• The influence of soil moisture on thunderstorm initiation is directly proportional to the magnitude of vertical wind shear.
• The directional wind shear determines whether locally dry or wet soil favors thunderstorm initiation:
  • Positive directional wind shear (aligned low- and mid-height winds) favors initiation over wet soil.
  • Negative directional wind shear (opposite low- and mid-altitude winds) favors initiation over dry soil.
• Favorable combinations of spatial soil moisture gradients and directional wind shear lead to faster-forming, more intense thunderstorms with increased lightning activity and greater accumulated rainfall.
• These findings allow for pinpointing intense thunderstorm initiation within 10–40 kilometers and 15–60 minutes.

Contributions

• Provides a robust, observation-based explanation for the previously observed phenomenon of thunderstorm initiation over locally dry soils in West Africa.
• Advances the understanding of the physical processes governing thunderstorm initiation, particularly the role of land–atmosphere interactions and atmospheric dynamics.
• Offers a pathway to significantly improve the location and timing accuracy of short-timescale thunderstorm forecasts, which is crucial for human transportation, energy, agriculture, and storm-water management.
• Emphasizes the value of multi-sensor and multi-satellite analyses for deepening scientific understanding and refining both Earth-observing systems and atmospheric models.

Funding

Not specified in the provided News & Views article.

Citation

@article{Ferguson2026Do,
  author = {Ferguson, Craig R.},
  title = {Do wet or dry soils trigger thunderstorms? It depends on how the wind blows},
  journal = {Nature},
  year = {2026},
  doi = {10.1038/d41586-026-00376-4},
  url = {https://doi.org/10.1038/d41586-026-00376-4}
}