Convection Initiation Dataset

Twice as frequent over mountains

Reveals spatial distribution and surface thermal heterogeneity controls of convection initiation, providing a high-resolution benchmark for severe convective weather nowcasting.

Wei, Qian · Sun, Jianhua · Meng, Xianhong · Zhang, Yuanchun · Zheng, Linlin · Ma, Zheng

Atmospheric Research 2026

Specifications

Total CI events

{'zh': '11646', 'en': '11646'}

Frequency ratio (mountains/plains)

{'zh': '2', 'en': '2'}

Initiation elevation

{'zh': '400-600', 'en': '400-600'} m

Advantages

Twice as frequent over mountains

Mountains experience twice as many CIEs as plains even under weaker instability and vertical wind shear, indicating that terrain lifting or thermal heterogeneity can partly compensate for large-scale conditions.

Clear noontime triggering window

A single peak in CI frequency occurs at noon (12:00–13:00 BJT) across all terrain types, coinciding with maximum thermal instability and highest initiation elevations, providing a precise timing reference for warnings.

Soil moisture heterogeneity aids initiation

Mountain CIEs typically occur in regions with higher soil moisture than surrounding areas and proximity to areas with enhanced surface heat fluxes, which can generate mesoscale thermal circulations favorable for initiation.

Applications

• severe convective nowcasting：Provide statistical priors on terrain-dependent triggering to improve warning placement and timing.
• regional climate modeling：Used to evaluate model performance in simulating diurnal cycle and frequency of initiation over complex terrain.
• complex terrain weather monitoring：Reveal the role of soil moisture heterogeneity in noontime initiation over mountains, guiding observation network design.