NASA's TRMM Satellite Provides a Rainfall Map of Mirinae's Flooding Rains

Typhoon Mirinae dropped heavy rain over the central Philippines after hitting as a category two typhoon with wind speeds of 85 knots (~98 mph). Mirinae weakened to a tropical storm as it moved into the South China Sea but briefly increased to typhoon strength just before hitting Vietnam on Monday, November 2 in the southern coastal province of Phu Yen.

The Tropical Rainfall Measuring Mission (TRMM) satellite is managed by NASA and the Japanese Space Agency, JAXA. From its vantage point in space, TRMM flew over Typhoon Mirinae during its lifetime and catalogued its rainfall.

TRMM-based, near-real time Multi-satellite Precipitation Analysis (TMPA) at the NASA Goddard Space Flight Center, Greenbelt, Md. was used to monitor rainfall with Mirinae. Rainfall totals were calculated for the period from October 26 to November 2, 2009. Tropical storm, typhoon and tropical depression symbols were overlaid to show the locations of Mirinae from when it came ashore in the eastern Philippines until being downgraded to a tropical depression over Vietnam.

The TRMM rainfall analysis indicated that Mirinae dropped heavy rainfall with totals over 200 mm (~7.8 inches) in an area southeast of Manila in the Philippines. Typhoon Mirinae dropped heavy rainfall over a much larger area of Vietnam with a small area having rainfall totals over 275 mm (~10.8 inches). As with typhoon Ketsana in late September, Mirinae pulled moist air from the South China Sea and forced it up over terrain causing the heaviest rainfall to occur north of the typhoon.

Typhoon Ketsana took a similar path to Mirinae when it caused disasters in the Philippines and Vietnam in late September 2009. Tropical storm Ketsana took a more northern track, also making a final landfall in Vietnam.

Heavy rain amounts (from satellites) and flood potential calculations (from a hydrological model) are updated every three hours globally with the results shown on the “Global Flood and Landslide Monitoring” TRMM web site pages (http://trmm.gsfc.nasa.gov).

Text credit: Hal Pierce, SSAI/NASA Goddard Space Flight Center