On the relay propagation of deep convection leading to a heavy rainfall event in a weak‐wind urban environment

Quarterly Journal of the Royal Meteorological Society, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 22, 2025

Abstract This study examines the convection initiation (CI) and subsequent continuous propagation of storms from Shanghai–Suzhou–Wuxi–Changzhou city belt, which produce an afternoon heavy rainfall event at a distance 70–100 km downstream over coastal region, using 1‐km grid‐spacing cloud‐permitting simulation observed radar reflectivity surface data. The regional environment is characterized by light winds, high convective available potential energy with dry air in upper troposphere under influences lake sea breezes. Results show importance urban effects interacting breezes CI on downwind side belt. By tracing individual relation to convectively generated cold outflows, we find recurrences old locally dissipating, after dropping rainfall, new forming outflow boundaries until reaching region. mode storm termed relays that are governed cold‐pool dynamics conditionally unstable weak flows. While some during their relay merged into larger‐sized clusters, entities still remain separated each other. However, these clusters tend have higher rates longer lifespans than unmerged storms. It found produced few mergers within linear mesoscale system A single merger can hourly rate 95 mm·hr −1 due its quasi‐stationarity ample moisture supply

Language: Английский

Identification and characteristics of regional rainstorm events in China based on a dual-threshold method

Atmospheric Research, Journal Year: 2025, Volume and Issue: unknown, P. 108081 - 108081

Published: March 1, 2025

Language: Английский