The Structure and Decay of a Rainband in Hurricane Irene (1981)

Abstract The mesoscale thermodynamic, kinematic and reflectivity structure of a rainbandobserved in Hurricane Irene on 27 September 1981 is presented. Data are from 16 aircraft passes, from 150 to 4700 m MSL through the rainbandwhich was located SSW of the circulation center of the northward moving hurricane. Cross sections of the rainbandas a function of height and radial distance from the storm center reveal the following: 1) little or no decrease of θe in the subcloud layer associated with the weak convective cellsin the rainband; 2) large differences in static stability between the north and south sides of the band; 3) a change of the radial wind component in the subcloud layer, from flow toward the circulation center to flow away from it as the rainbandweakens. The decay of the rainbandis believed to be related to mesoscale subsidence and the location of the rainbandrelative to the motion of the hurricane. Melting and evaporation of hydrometeors falling between the eyewall and the rainbandare...