The cloud/precipitation features in the Rapid Intensifying TC over NW Pacific from satellite observation

Contact: Liu, Chian-Yi / / (02) 2787-5877, 大氣環境遙測研究室

Key words: 熱帶氣旋、快速增強、深對流雲、降水、雲微物理與雲光學特性

The sketch diagram of cloud/precipitation features for Tropical Depression (Left panel) and Tropical Cyclone (right panel) under the intensification stages.

We want to know if there are unique features of deep convective cloud (DCC), rain, and cloud properties that can be used to predict the rapid intensification (RI) of a tropical cyclone. RI can be predicted using DCC in all storm categories. Precipitation is also useful in anticipating RI but for weaker storms only. The deep convection, rain, and cloud properties near the center of rapidly intensifying storms suggests that clouds within that region has deepened already as compared to the clouds that far away from the center. All storms that are rapidly intensifying share the same DCC, rain, and cloud properties characteristics near the center. The different characteristics observed at the beginning and at 24 hr of RI are more related to their intensities and intensification rates (or the size of their radii of maximum wind).

Key points

  • Deep convective cloud's (DCC's) radial distribution can identify an impending rapid intensification (RI), whereas precipitation can be used to anticipate RI in weak tropical cyclones (TCs)
  • RI TCs, regardless of their intensities, have common DCC, precipitation, and cloud properties characteristics at the TC center
  • Characteristics found in initial and continuing RI are artifacts of their intensities and RI rates (or radius of maximum wind sizes)

More information

  • Liu, C.-Y., Punay, J. P., Wu, C.-C., Chung, K.-S., & Aryastana, P. (2022). Characteristics of deep convective clouds, precipitation, and cloud properties of rapidly intensifying tropical cyclones in the western North Pacific. Journal of Geophysical Research: Atmospheres, 127, e2022JD037328.
  • Liu, C.-Y., Chiu, C.-H., Lin, P.-H., & Min, M. (2020). Comparison of cloud-top property retrievals from Advanced Himawari Imager, MODIS, CloudSat/CPR, CALIPSO/CALIOP, and radiosonde. Journal of Geophysical Research: Atmospheres, 125, e2020JD032683.