Statistical study of CAPE and daytime thunderstorms in Singapore

A statistical study has been performed to correlate CAPE in Singapore and daytime thunderstorms. CAPE data from 2002-2011 was calculated using soundings at 00UTC (8am LT). By plotting the monthly average CAPE, it was found that CAPE reaches a peak during late May and June when Singapore is in the transition to Southwest Monsoon. This is also the time when Singapore experiences relatively higher number of thunderstorm days. The lowest CAPE is observed during the dry phase of Northeast Monsoon (late January-February), which corresponds to the least number of thunderstorms day according to climatological record. However, CAPE does not have a direct relationship with the amount of rainfall. Larger CAPE does not necessarily lead to higher amount of total rainfall. Similar to the mid-latitude, in Singapore, probability of thunderstorm increases when CAPE value rises. Interestingly, large CAPE does not always lead to intense convection in Singapore. This study will also discuss the possible reasons for such observations.