Seasonal Climate Outlook Message for August to November 2005

The bottom line

Climate Watch 30/08/05

According the Bureau of Meteorology "El Niño wrap up" at www.bom.gov.au/ the likelihood of a classic El Niño event developing this year is low.

In terms of output from 12 surveyed reputable ocean or coupled ocean/atmosphere forecast models, 9 are showing a neutral SST pattern through to January 2006 with 2 showing an El Niño SST pattern and 1 showing a La Niña pattern. For more information on conditions in the Pacific try the IRI for Climate Prediction at http://iri.ldeo.columbia.edu/ or the US Climate Prediction Centre at www.cpc.ncep.noaa.gov/

Of much interest this week has been Category 5 Hurricane Katrina in the Gulf of Mexico. The terms hurricane and typhoon are regionally specific names for a strong tropical cyclone. Hurricane is usually used for tropical cyclones in the North Atlantic and northeast Pacific east of the dateline. Typhoon is used for tropical cyclones in the northwest Pacific west of the dateline with the term tropical cyclone used in the southwest Pacific and Indian Ocean.

For a hurricane or cyclone to be rated as Category 5 it must have winds greater than 135 knots or 249 km/hr. Tropical Cyclone Vance which crossed the Western Australian coastline near Exmouth in March 1999 was category 5. A record wind gust speed for the Australian mainland of 267 kilometres per hour was recorded at the Learmonth Meteorological Office, 35 kilometres south of Exmouth. To get more information on hurricanes including satellite images try http://www.nhc.noaa.gov/ In Australia the source to use for information and warnings etc on cyclones remains the Bureau of Meteorology at www.bom.gov.au/

Research has shown that with an El Niño sea surface temperature (SST) pattern there are fewer cyclones that cross the Queensland coastline. It will be interesting to see what happens this summer if SST patterns remain neutral.

As of the 30th August the 30-day average of the SOI is minus 6.2. Daily updates on the SOI are available on (07) 46881439. The latest rainfall probability maps are at www.dpi.qld.gov.au/climate or www.longpaddock.qld.gov.au

Staff from the DPI&F will be at Ag-Show in Toowoomba on the 6th to the 8th September to answer questions. For more information call the DPI Call Centre on 13 25 23 or (07) 3404 6999.