Some Special Characteristics of Track and Intensity of Typhoons Over the Western North Pacific

Abstract

ABSTRACT Joint Typhoon Warning Center (JTWC) Best Track data from 1995 to 2014 are processed to examine some specific patterns and trends shown by Typhoons over the Western North Pacific. With a multivariate dataset of 588 TC cases in hand, we carry out a sub-domain analysis by dividing the Western North Pacific region into domains of 2°x2° and find the preferred regions of genesis, favourable direction of movement, steep recurvature, rapid intensification, and rapid decay. The region from longitude 132°E to 134°E and latitude 16°N to 18°N showed the highest number of cases (19) for rapid intensification (RI) and a general pattern is found that the RI systems occurred mostly in the later half of the year with a negative Pacific Decadal Oscillation (PDO) index. Similarly, the domain from longitude 114°E to 116°E and latitude 26°N to 28°N had the highest probability of 0.857 for rapid decay. The probabilities of recurvature for each sub-domain were calculated for angles 30°, 45°, 60°, 90°, 120° and 150°. The sub-domain around longitude 118°E and latitude 12°N had the steepest recurve of 168.69°. It also had a high probability of 0.714 for a recurvature of greater than 90°. The most taken direction of movement of typhoons around the Western North Pacific were analysed in different ways and along the 16 points of compass, the direction from 270° to 292.5° was found to be the most preferred direction of movement.