PEAC CENTER TROPICAL CYCLONE OUTLOOK
The PEAC tropical cyclone outlook for the upcoming typhoon season of 2010 calls for near normal activity in the western North Pacific basin. There should be fewer cyclones (with respect to normal and with respect to 2009) traversing Micronesia as El Niño wanes and ENSO-neutral conditions return. Also, the geographical distribution of western North Pacific tropical cyclones should return to a near normal pattern, with near-normal risk of typhoon occurrence from Chuuk westward. Islands from Pohnpei eastward into the RMI experience tropical storms and typhoons primarily during El Niño, and the risk of a destructive tropical cyclone in these locations is considered low during 2010. The risk of a damaging impact by a hurricane or strong tropical storm in American Samoa is considered low through June 2010.
On December 4, 2008, the Tropical Storm Risk Research Group1 (http://www.tropicalstormrisk.com/) issued the following assessment of tropical cyclone activity for the Australian region:
The TSR (Tropical Storm Risk) early December forecast update for Australian-region tropical cyclone activity in 2008/9 anticipates activity approximately 10% above the 1975/6-2007/8 climate norm. The forecast spans the Australian season from the 1st November 2008 to the 30th April 2009 and is based on data available through the end of November 2008. Our main predictor is the observed anomaly in October-November Niño 4 sea surface temperatures (SST) which is below average at -0.50 C. … Thus we expect Australian basin cyclone activity and landfalling numbers to be above-average in 2008/9.
Our Australian-region (100 E to 170 E), while slightly non-standard, is selected to provide the best overview for tropical cyclone activity around the whole of Australia.
There is a 45% probability that Australian-region tropical storm numbers in 2008/9 will be above average (defined as more than 12 tropical storms), a 45% likelihood they will be near normal (defined as between 9 and 12 tropical storms) and only a 10% chance they will be below normal (defined as less than 9 tropical storms). …
The PEAC forecast considers input from two seasonal outlooks for tropical cyclone activity in the western North Pacific basin: (1) The City University of Hong Kong Laboratory for Atmospheric Research, under the direction of Dr. J. C-L. Chan, and, (2) The Benfield Hazard Research Centre Tropical Storm Risk (TSR) Research Group at University College London, UK, led by Dr Adam Lea and Professor Mark Saunders.