FAQ--  WESTERN AUSTRALIA
Areal coverage - area south of 0° and between 90°E and 125°E.

Names for the 2007/2008 season

Season - October through April
Average number of tropical cyclones in a year -- 6.6
Average number of tropical cyclones in a "normal season" -- 6.3
Most active month -- January - average 1.7 storms/year
Most active period -- December through April - 86.44 % of all storms
Most storms in a single season - 12 in 1993/1994
Fewest storms in a single season -- 2 in 1994/1995

The graphs below have been created using the "best track" data from 1979 to 2006 courtesy of JTWC. Click on the graph to enlarge.

Tropical Cyclones by Year	Tropical Cyclones by Month	Tropical Cyclone Probability by Month	Tropical Cyclones crossing to Southwest Indian Ocean by Year

Cyclone rating designation process --  MSW Averaging Period: 10 minutes
      Tropical LOW - term is used to describe disturbances ranging from
         diffuse, ill-defined low-pressure areas all the way to well-
         organized tropical depressions with MSW up to 33 kts
      Tropical Cyclone - MSW in range of 34-63 kts/ Dvorak rating ranging
         from a strong T2.5/weak T3.0 to T4.0
      Severe Tropical Cyclone - MSW exceeding 63 kts/ Dvorak T4.5 or
         higher

     Warnings in the Western Australian Region are issued by Perth (Western Australia) with Darwin being the RSMC for the region.  The Australian centres avoid use of the term "tropical depression" in public advices primarily to reduce possible confusion with the use of the term "depression" in association with extratropical systems; and also possibly because until recently (early 1990's), in the Southwest Indian Ocean Basin, a "tropical depression" meant any system with winds up to 63 kts (hurricane force).  The Australian TCWCs utilize a conversion factor of 0.88 or 0.90 to modify the 1-minute Dvorak scale to an equivalent 10-minute average scale.

TCWC = Tropical Cyclone Warning Center
MSW = Mean Surface Wind
JTWC = Joint Typhoon Warning Center

FAQ--  EASTERN AUSTRALIA
Areal coverage - area south of 0° and between 137°E and 160°E.

Names for the 2007/2008 season

Season - October through April
Average number of tropical cyclones in a year -- 3.4
Average number of tropical cyclones in a "normal season" -- 3.3
Most active month -- February - average 1.1 storms/year
Most active period -- December through February - 79.12% of all storms
Most storms in a single season - 7 in 1984/1985 and 1998/1999
Fewest storms in a single season -- 1 in 1982/1983 , 1987/1988 , 1991/1992 , 2000/2001
The graphs below have been created using the "best track" data from 1979 to 2006 courtesy of JTWC. Click on the graph to enlarge.

Tropical Cyclones by Year	Tropical Cyclones by Month	Tropical Cyclone Probability by Month	Tropical Cyclones crossing to other regions by Year

Cyclone rating designation process --  MSW Averaging Period: 10 minutes
      Tropical LOW - term is used to describe disturbances ranging from
         diffuse, ill-defined low-pressure areas all the way to well-
         organized tropical depressions with MSW up to 33 kts
      Tropical Cyclone - MSW in range of 34-63 kts/ Dvorak rating ranging
         from a strong T2.5/weak T3.0 to T4.0
      Severe Tropical Cyclone - MSW exceeding 63 kts/ Dvorak T4.5 or
         higher

     Warnings in the Eastern Australian Region are issued by Brisbane (Queensland Australia) with Darwin being the RSMC for the region.  The Australian centres avoid use of the term "tropical depression" in public advices primarily to reduce possible confusion with the use of the term "depression" in association with extratropical systems; and also possibly because until recently (early 1990's), in the Southwest Indian Ocean Basin, a "tropical depression" meant any system with winds up to 63 kts (hurricane force).  The Australian TCWCs utilize a conversion factor of 0.88 or 0.90 to modify the 1-minute Dvorak scale to an equivalent 10-minute average scale.

TCWC = Tropical Cyclone Warning Center
MSW = Mean Surface Wind
JTWC = Joint Typhoon Warning Center

FAQ--  NORTHERN AUSTRALIA
Areal coverage - area south of 0° and between 125°E and 137°E.

Names for the 2007/2008 season

Season - October through April
Average number of tropical cyclones in a year -- 1.8
Average number of tropical cyclones in a "normal season" -- 1.8
Most active month -- December -  average 0.5 storms/year
Most active period -- December through January - 49.76% of all storms
There has not been a storm recorded between May 1 and November 30
Most storms in a single season - 4 in 2000/2001
Fewest storms in a single season -- 0 in several years, latest 2005/2006

The graphs below have been created using the "best track" data from 1979 to 2006 courtesy of JTWC. Click on the graph to enlarge.

Tropical Cyclones by Year	Tropical Cyclones by Month	Tropical Cyclone Probability by Month	Tropical Cyclones crossing to other regions by Year

Cyclone rating designation process --  MSW Averaging Period: 10 minutes
      Tropical LOW - term is used to describe disturbances ranging from
         diffuse, ill-defined low-pressure areas all the way to well-
         organized tropical depressions with MSW up to 33 kts
      Tropical Cyclone - MSW in range of 34-63 kts/ Dvorak rating ranging
         from a strong T2.5/weak T3.0 to T4.0
      Severe Tropical Cyclone - MSW exceeding 63 kts/ Dvorak T4.5 or
         higher

     Warnings in the Northern Australian Region are issued by the TCWC at Darwin (Northern Territory), with Darwin being the RSMC for the region.  The Australian centres avoid use of the term "tropical depression" in public advices primarily to reduce possible confusion with the use of the term "depression" in association with extratropical systems; and also possibly because until recently (early 1990's), in the Southwest Indian Ocean Basin, a "tropical depression" meant any system with winds up to 63 kts (hurricane force).  The Australian TCWCs utilize a conversion factor of 0.88 or 0.90 to modify the 1-minute Dvorak scale to an equivalent 10-minute average scale.