The 30–60-day Madden–Julian oscillation (MJO) has been documented in previous research to impact tropical cyclone (TC) activity for various tropical cyclone basins around the globe. TheMJOmodulates largescale convective activity throughout the tropics, and concomitantly modulates other fields known to impact tropical cyclone activity such as vertical wind shear, midlevelmoisture, vertical motio...

Improve our understanding of the physical processes by which (a) 3-D environmental shears, in particular the low-level meridional shear and upper-level vertical shear affect inner core structure and intensity, and (b) the mesoscale vortices, outer spiral rainbands, inner spiral rainbands, and the eyewall interact and affect TC development and intensity change. General questions to be addressed ...

A review of the science on the relationship between climate change and tropical cyclones (TCs) is presented. Topics include changes in aspects of tropical climate that are relevant to TC activity; observed trends and low-frequency variability of TC activity; paleoclimate proxy studies; theoretical and modeling studies; future projections; roadblocks to resolution of key issues; and recommendati...

Since 22 April 2009, the Japan Meteorological Agency (JMA) has issued five-day tropical cyclone (TC) track forecasts. This paper introduces these forecasts, including the method used, interpretation of the results obtained, forecast cases and future challenges. One of the forecast’s unique aspects is its determination of the radius of a 70% probability circle (PC) using the level of forecast un...

The effects of storm-induced sea surface temperature (SST) cooling on hurricane intensity are investigated using a 5-day cloud-resolving simulation of Hurricane Bonnie (1998). Two sensitivity simulations are performed in which the storm-induced cooling is either ignored or shifted close to the modeled storm track. Results show marked sensitivity of the model-simulated storm intensity to the mag...

The advance in targeted observations of tropical cyclone movement is reviewed in this article. The targeted observations from DOTSTAR (Dropwindsonde Observations for Typhoon Surveillance near the Taiwan Region) in understanding and improving the tropical cyclone track predictability is highlighted, along with the progress of the field program of THORPEX-PARC in the summer of 2008. The impact of...

A 42-yr study of eastern North Pacific tropical cyclones (TCs) undergoing extratropical transition (ET) is presented using the Japanese 55-yr Reanalysis dataset. By using cyclone phase space (CPS) to differentiate those TCs that undergo ET from those that do not, it is found that only 9% of eastern North Pacific TCs that developed from 1971 to 2012 complete ET, compared with 40% in the North At...

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...