TROPICAL CYCLONE ACTIVITY (1st Quarter Summary)

The PEAC archives western North Pacific tropical cyclone numbers, track coordinates, and 1-minute average maximum sustained wind taken from operational warnings issued by the Joint Typhoon Warning Center (JTWC) of the U. S. Air Force and Navy, located at Pearl Harbor, Hawaii. Western North Pacific tropical cyclone names are obtained from warnings issued by the Japanese Meteorology Agency (JMA), which is the World Meteorological Organization's Regional Specialized Meteorological Center (RSMC) for the western North Pacific basin. The PEAC archives South Pacific tropical cyclone names, track coordinates, central pressure, and 10-minute average maximum sustained wind estimates from advisories issued by the Tropical Cyclone Warning Centers at Brisbane, Nadi, and Wellington. The numbering scheme and the 1-minute average maximum sustained wind estimates are taken from warnings issued by the JTWC. There are sometimes differences in the statistics (e.g., storm maximum intensity) for a given tropical cyclone among the agencies that are noted in this summary.

For purposes of seasonal statistics, the JTWC archives Southern Hemisphere tropical cyclone activity for 2006 within the period July 2005 through June 2006. The first five TCs of in the Southern Hemisphere for the 2006 “season” occurred in the South Indian Ocean during October through early January. In mid-January, the South Pacific experienced it s first tropical cyclone – TC 06P (Tam) – that tracked south of Samoa as a weak tropical storm. This TC was soon followed by TC 07P (Urmil) that passed near the Tongan Island group with intensity just shy of hurricane force. The next two Southern Hemisphere TCs – 08S and 09S (Daryl and Bolestse) – were in the South Indian Ocean . To finish off January’s Southern Hemisphere TC activity, Cyclone Jim (10P) formed off the east coast of Australia and moved toward Noumea where it dissipated in early February. During the month of February, five TCs occurred in the southern Hemisphere: two in the South Pacific and three in the South Indian Ocean . Cyclone Vaianu (TC 11P) tracked close to Tonga, and small Cyclone Kate meandered for several days close to the southeastern tip of Papua New Guinea. March through April 2006 was a very active period of TC activity in the Southern Hemisphere: four TCs occurred in the South Indian Ocean, and three TCs – Cyclone Larry (17P), Cyclone Wati (18P), and Cyclone Monica (23P) – occurred in the South Pacific. Cyclone Larry made landfall along the northeast coast of Australia near the town of Innisfail. Larry was a major cyclone earning the highest Category 5 intensity classification by the Australian Bureau of Meteorology. Cyclone Monica also peaked at the highest Category 5 intensity while it was in the Gulf of Carpentaria . The 2006 cyclone season of the Southern Hemisphere should wind down soon. So far there has been a total of 23 Southern Hemisphere tropical cyclones numbered by the JTWC within the 2006 cyclone season, compared to a normal seasonal total of 28.

In the Northern Hemisphere, there were two tropical cyclones during the First Quarter of 2006: one in the Arabian Sea (TC 01A) and one in the western North Pacific (TC 01W). TC 01W was not named by the JMA. It spent its entire life at low latitude (near 5ºN), passing south of Koror, Palau in early March, moving westward from there into the Philippine Archipelago where it dissipated. The western North Pacific typically experiences two or three tropical cyclones through April of the calendar year. Early season tropical cyclone activity in the western North Pacific is enhanced during El Niño years, and suppressed in the years that follow El Niño. During La Niña, basin-wide tropical cyclone numbers may be near normal, but the activity is typically shifted to the west.