Typhoon Koppu

  • A surface pressure chart illustrating the position of Typhoon Koppu and Typhoon Champi, overlayed with the forecast 24 hour rainfall accumulation (in millimeters).

    A RGB satellite animation of violent Typhoon Koppu as it nears landfall on the east coast of the Luzon region in the northern Philippines. (Credit: NOAA).

  • Typhoon Koppu
    17.10.2015 15:22

    The extremely active Pacific typhoon season continues as two very strong storms rage in the west Pacific. Typhoon Champi is currently strengthening rapidly near the Northern Marian Islands. However, its cousin Typhoon Koppu is tracking ominously towards the highly populated Philippines.


    Typhoon Koppu had gained ‘Very Strong’ status as of Saturday morning with a central pressure of 930hPa and winds gusting to 250km/hr (155mph) around its centre. The storm is expected to reach ‘Violent’ status by early Sunday with its central pressure expected to fall to 915hPa and wind gusts around its centre expected to reach a destructive 280km/hr (174mph).

    The region of Luzon in the north of the Philippines, home to almost 98 million people, is in the path of Koppu. President Benigno Aquino has warned more than 6 million people in the typhoons direct path to evacuate. The storm will come ashore early on Sunday bringing violent winds, intense rainfall and a storm surge of as much as 6 foot.

    The wind is expected to gust to more than 200km/hr (125mph) when it comes ashore bringing the potential for widespread infrastructural damage; uprooted trees, downed power lines and has the potential to rip roofs off homes. However, the biggest threat from Koppu will come from the intense rainfall that is expected to fall across the region.

    A complex synoptic pattern across the western Pacific is expected to keep Koppu close to the Luzon region for almost 3 days. The Fujiwhara interaction between Koppu and Champi will cause Koppu to stall over the northern Philippines, allowing the system to dump unprecedented amounts of rainfall. Some numerical model guidance suggests as much as 1 metre of precipitation will fall in some areas.

    What is the Fujiwhara Interaction/Effect ?

    The interaction occurs between two nearby typhoons, usually the vortices are less than one thousand kilometres apart. The interaction causes the two cyclones to orbit counter-clockwise about a point between the two cyclone centres. In some interactions the two cyclones will eventually spiral towards eachother and merge. The effect was hypothesised by a Japanese meteorologist Sakuhei Fujiwhara.

    Typhoon Haiyan

    The last time such a televised storm warning was issued by the Phillipine authorities was prior to the landfall of Typhoon Haiyan in early-November 2013. Typhoon Haiyan tore through the region causing over 7,300 deaths and causing the complete destruction of towns and villages. Typhoon Haiyan was one of the strongest tropical cyclones ever recorded with the Japanese Typhoon Warning Centre estimating the system’s one minute sustained winds to be 315km/hr (196mph). The regions worst affected by Haiyan are still rebuilding and recovering today.

    By: Matthew Martin