Parts of the Malay Peninsula, including southern Thailand and northern Malaysia, were hit hard by severe flooding after torrential monsoon rains that fell over two weeks in mid-December. December is part of the region’s northeast monsoon, when prevailing northeasterly winds flow into the region from across the South China Sea. Because the winds carry abundant moisture, heavy rains that last several days are common during the northeast monsoon. In 2005, several multi-day rainy episodes followed closely together with little break, resulting in widespread flooding. Some regions received even more rain when the prevailing winds butted up against mountains and more moisture was squeezed out of the sky. According to news reports, floods and mudslides have driven thousands from their homes, isolated thousands more, and caused at least 30 deaths in Thailand and Malaysia.
The flood-inducing rains are illustrated in this image, created using rainfall totals measured by the Tropical Rainfall Measuring Mission (TRMM) satellite between December 12 and December 19, 2005. Rainfall totals in excess of 300 millimeters (12 inches), shown in red, extend all along the eastern coastline of the Malay Peninsula from around Pak Phanang in southern Thailand to near Chukai in Malaysia. The highest totals, approaching 500 millimeters (20 inches) correspond to the darkest red areas near Songklha and Hat Yai along the southern Thai coastline. Not surprisingly, these were among the communities that suffered the most damage.
The TRMM-based, near-real-time, Multi-satellite Precipitation Analysis (MPA) at NASA Goddard Space Flight Center monitors rainfall over the global tropics. TRMM is a joint mission between NASA and the Japanese space agency, JAXA.