10:45 AM - 11:00 AM
[AAS03-07] Climatological Characteristics of Mesoscale Convective Systems in the Philippines
Keywords:mesoscale convective systems, climatology, convection, tropics
Studies on severe weather in the Philippines, a part of the Maritime Continent where frequent and intense convective activities occur, focus predominantly on synoptic-scale systems (e.g., tropical cyclones). The characteristics and formation mechanisms of mesoscale convective systems (MCSs) in the Philippines still remain understudied. Motivated by these research gaps, a long-term MCS climatology (2000-2019) over the Philippines was constructed using the global MCS tracking database of Feng et al. (2021), and its large-scale environments are investigated to understand the formation of MCSs.
Results show that large-scale flows primarily affect MCS formation. MCSs occur more frequently during the peak of the Asian summer monsoon (JJA), producing large precipitation amounts over the west of the Philippines. Meanwhile, the Asian winter monsoon during DJF has a different effect on MCS formation in the Philippines as it does not directly correspond to high occurrences of MCSs. However, despite the fewer MCS formations, higher precipitation amounts are still produced over the southeast of the Philippines. It is found that among all seasons, DJF tends to have the longest lifetime, largest precipitation area, and slowest moving systems, suggesting that stronger MCSs are formed. In addition, the abundant moisture accompanied by the easterlies and the presence of the northerly cold surges during winter favored the enhancement of MCSs despite the moderate CAPE (<800 J kg-1) environment.
Reference:
Feng, Z., Leung, L. R., Liu, N., Wang, J., Houze Jr, R. A., Li, J., ... & Guo, J. (2021). A global high-resolution mesoscale convective system database using satellite-derived cloud tops, surface precipitation, and tracking. Journal of Geophysical Research: Atmospheres, 126(8), e2020JD034202.
Results show that large-scale flows primarily affect MCS formation. MCSs occur more frequently during the peak of the Asian summer monsoon (JJA), producing large precipitation amounts over the west of the Philippines. Meanwhile, the Asian winter monsoon during DJF has a different effect on MCS formation in the Philippines as it does not directly correspond to high occurrences of MCSs. However, despite the fewer MCS formations, higher precipitation amounts are still produced over the southeast of the Philippines. It is found that among all seasons, DJF tends to have the longest lifetime, largest precipitation area, and slowest moving systems, suggesting that stronger MCSs are formed. In addition, the abundant moisture accompanied by the easterlies and the presence of the northerly cold surges during winter favored the enhancement of MCSs despite the moderate CAPE (<800 J kg-1) environment.
Reference:
Feng, Z., Leung, L. R., Liu, N., Wang, J., Houze Jr, R. A., Li, J., ... & Guo, J. (2021). A global high-resolution mesoscale convective system database using satellite-derived cloud tops, surface precipitation, and tracking. Journal of Geophysical Research: Atmospheres, 126(8), e2020JD034202.