Analyses of Ring of maximum Wind, Ring of Maximum Pressure Gradient, Inflow angle and RMW in Tropical Storm

Value of Constant in Fletcher's equation for maximum wind has been analytically re-examined with the help of gradient wind equation. Suitable approximations lead us to the mathematical result that maximum angular velocity is inversely proportional to square root of the peripheral radius, provided central an ambient pressure and the ring of maximum wind (RMW) are same for any two different tropical storms. Mathematical consistency demands that the value of RMW must be larger than the value of radius of maximum pressure gradient (rpmax). Predominance of radial component of velocity over the angular component, at places, is also possible, close to RMW. Observations of Mukherjee et al(1981) over Bay of Bengal are the cumulative effects of asymmetry causing factors e.g. gradient in earth's vorticity, vertical shear, cold water tongue which induces overlying boundary layer modification, landfall and Beta-gyres. These could be responsible for large inflow angle of 60 to 70 dgrees, at times, in preferred sectors. It is further noted that Hydromet pressure profile cannot truly represent the cyclone pressure field since there is a point of inflection at r = rmax close to the centre of tropical storm.