Dynamics of short rainfall storms in a small scale urban area in Coly Limper, Malaysia

Short term storm rainfalls are recorded with a dense network of fine resolution rain gauges well distributed in a small urban catchment in Kuala Lumpur, Malaysia. The period of data collection covers the south-west monsoon (July-September), inter monsoon (October) and partly the north-east monsoon (November-December) seasons. This paper presents some findings with reference to the dynamic properties of short rainfall storms using the method of vector analysis and farther correlation analysis. Good accuracy of data and good synchronisation between the gauges have been achieved thus a meaningful interpretation of the obtained results was made possible. The selected 30 storms have been used to determine the velocities and direction of movement of the storm cells. A correlation study was undertaken to relate the calculated storm velocities and directions with the observed wind velocities and directions from different altitudes. Results show that statistically significant correlation was achieved between the calculated storm velocities and the hourly mean surface wind velocities. In contrast to studies carried out in other climate zones, no significant correlations were obtained between observed storm velocities and directions on ground level versus high altitude measured wind velocities and directions. The average maximum intensities has been found to be correlated with the average storm depths.