The number of tropical cyclones observed in the Australian region (south of equator; 105-160~ has apparently declined since the start of reliable (satellite) observations in the 1969/70 season. However, the number of more intense cyclones (with minimum pressures dropping to 970 hPa or lower) has increased slightly. The numbers of weak (minimum pressures not dropping below 990 hPa) and moderate ...

Tropical cyclones are relatively rare weather events, yet they consistently rank among the world’s deadliest and costliest natural hazards. In the United States, tropical cyclones account for nearly $10 billion annually in economic damages (1), and damages from Hurricane Sandy (2012) are estimated to be over $50 billion. Understanding the role of these events within Earth’s climate system is of...

[1] Midlatitude cyclone tracks over the Southern Ocean are constructed for the 1999–2006 period using two surface data sets: European Centre for Medium-range Weather Forecasts (ECMWF) sea-level pressure analyses on one hand, and on the other hand modified analyses in which high-wavenumber pressure variability derived from scatterometer swaths has been injected with a wavelet-based method. A com...

Previous studies have found broad distributions, resembling power laws for different measures of the size of rainfall events. We investigate the large-event tail of these distributions and find in one measure that tropical cyclones account for a large proportion of the very largest events outside the scaling regime, i.e., beyond the cutoff of the power law. Tropical cyclones are sufficiently ra...

The prediction of extratropical cyclones by the European Centre for Medium-Range Weather Forecasts (ECMWF) and the National Centers for Environmental Prediction (NCEP) ensemble prediction systems (EPSs) has been investigated using an objective feature tracking methodology to identify and track the cyclones along the forecast trajectories. Overall the results show that the ECMWF EPS has a slight...

Rain gauge data, satellite IR brightness temperature and radar-estimated rain rate for five tropical cyclones from the 2005–06 to 2009–10 seasons that made landfall along the northwestern coast of Australia are analysed. It is the first time that the spatial rainfall distribution of landfalling tropical cyclones in the southern hemisphere has been systematically investigated. It is found that t...

The influence of oceanic changes on tropical cyclone activity is investigated using observational estimates of sea surface temperature (SST), air–sea fluxes, and ocean subsurface thermal structure during the period 1998– 2007. SST conditions are examined before, during, and after the passage of tropical cyclones, through Lagrangian composites along cyclone tracks across all ocean basins, with p...

the southern coasts of caspian sea is subjected to synoptic/mesoscale weather systemsranging from locally enhanced sea breeze formation and small local front systems to synoptic scale cyclones.this study presents climatology of cyclones over the southern coasts of caspian sea covering a ten year period1996-2005. altogether 57 cyclones were formed during the ten year period. anoticeable seasonal...

Tropical cyclogenesis is attributed to an equatorial wave when the filtered rainfall anomaly exceeds a threshold value at the genesis location. It is argued that 0 mm day (simply requiring a positive anomaly) is too small a threshold because unrelated noise can produce a positive anomaly. A threshold of 6 mm day is too large because two-thirds of storms would have no precursor disturbance. Betw...