WRD/TC.40/2
In Malaysia,
Altogether, there are twenty-two tropical cyclones (tropical storm intensity or higher) developed over the west Pacific Ocean, South China Sea and Philippines Island from 1 October 2006 to 30 September 2007. Table 1 shows the list of the nineteen tropical cyclones that developed over the west Pacific Ocean, two that developed over the northern South China Sea and one that formed over the northern PhilippinesIsland during this period. Nevertheless, there are only six tropical cyclones, as shown with an asterisk in this table, which caused impacts on the weather in Malaysia, particularly on the rainfall as well as the coastal waters. These tropical cyclones tracked close to Malaysia, within a distance of less than 700 km away. The convergence of northwesterly and southwesterly winds over the Malaysian region caused by these tropical cyclones had enhanced the afternoon convective activities. This winds convergence caused heavy and sometimes widespread rains over Malaysian region and strong southwesterly winds of 40-60 km/h and rough seas with waves up to 3.5 m over the coastal waters of northwest and east coast of Peninsular Malaysia, Sarawak and Sabah. Tropical cyclones that located far away from Malaysia caused no significant impacts on Malaysia. The tracks of the six tropical cyclones that tracked close to Malaysian region are shownin Figure 1.
Table 1: List of Tropical Cyclones and their Birth, Death and Life Time
No. / Tropical Cyclone Name / Birth / Death / Duration (Days)4 / Cimaron / 27-10-2006 / 04-11-2006 / 8
5 / Chebi / 09-11-2006 / 13-11- 2006 / 4
6 / Durian* / 26-11-2006 / 05-12-2006 / 8
7 / Utor* / 07-12-2006 / 14-12-2006 / 6
8 / Trami / 17-12-2006 / 18-12-2006 / 1
9 / Kong-Rey / 31-03-2007 / 06-04-2007 / 5
10 / Yutu / 17-05-2007 / 23-05-2007 / 5
11 / Toraji / 05-07-2007 / 05-07-2007 / 0
12 / Man-Yi / 08-07-2007 / 17-07-2007 / 8
13 / Usagi / 29-07-2007 / 04-08-2007 / 6
14 / Pabuk / 05-08-2007 / 09-08-2007 / 4
15 / Wutip / 08-08-2007 / 09-08-2007 / 1
16 / Sepat* / 12-08-2007 / 20-08-2007 / 7
17 / Fitow / 29-08-2007 / 08-09-2007 / 10
18 / Danas / 07-09-2007 / 11-09-2007 / 4
19 / Nari / 13-09-2007 / 17-09-2007 / 3
20 / Wipha* / 16-09-2007 / 19-09-2007 / 3
21 / Francisco* / 23-09-2007 / 25-09-2007 / 1
22 / Lekima* / 30-09-2007 / 02-10-2007 / 2
Figure 1: Tracks of the six tropical cyclones closest to Malaysia. The number in the circle represents the date of occurrence of the tropical cyclones.
The rain cloud clusters over the Malaysian region associated with the six tropical cyclones, as shown in the satellite imageries in Figure 2, indicate heavy and sometimes widespread rains over Malaysian. These heavy and sometimes widespread rains are depicted in the daily rainfall charts of selected meteorological stations from November to December 2006 and August to September 2007 as shown in Figures 3(a), 3(b), 3(c), (3d) and 3(e). Some of these charts may not show significant amount of rainfall as depicted by the corresponding satellite imageries as the heavy rains occurred not over but in the vicinities of these stations.
Figure 2:Satellite Imageries indicate the rain cloud clusters over Malaysian region during the tracking of the six tropical cyclones
Figure 3(a): Daily rainfall chart recorded by selected meteorological stations in Malaysia for November 2006: Typhoon Durian (26/11/06 – 05/12/06)
Figure 3(b): Daily rainfall chart recorded by selected meteorological stations in Malaysia for December 2006: Typhoon Utor (07/12/06 – 14/12/06)
Figure 3(c): Daily rainfall chart recorded by selected meteorological stations in Malaysia for August 2007: Typhoon Sepat (12/08/07 – 20/08/07)
Figure 3(d): Daily rainfall chart recorded by selected meteorological stations in Malaysia for September 2007: Typhoon Wipha (16/09/07 – 19/09/07)
Figure 3(e): Daily rainfall chart recorded by selected meteorological stations in Malaysia for September 2007: Tropical Storm Francisco (23/09/07 – 25/09/07) and Severe Storm Lekima (30/09/07 – 02/10/07)
In comparison with the weather conditions during the previous years, the southwest monsoon season (June to mid-September) experienced around this region for this year was slightly abnormal. Instead of the usually dry, hot and hazy weather conditions, most parts in Malaysia and Indonesia had received more rainfall during this period, June and July in particular. As a result, the usual impacts of the trans-boundary haze pollution over Malaysia were very much lessened.