The effects of latent heating on the extratropical transition of Typhoon Sinlaku

Extratropical Cyclones that formed from Tropical Cyclones (TC), e.g. Sinlaku, are asymmetric cold core systems as opposed to their warm core predecessors, and their radii of gale force winds (17 ms-1) may increase by a factor of two to three times their original radii. This expansion of the gale force winds as the TC undergoes extratropical transition (ET) can cause a significant amount of damage. In addition, these ET events can trigger and amplify baroclinic waves, indirectly leading to the generation of other powerful storms across the world. Such ET impacts are the imperative to study the dynamics and energetics involved with these initially tropical systems. Two sets of simulations using the Weather Research and Forecasting (WRF) model are examined to clarify the role of latent heating during ET. The results suggest that latent heating is crucial for the maintenance of the interacting midlatitude trough as well as the TC, and hence, that latent heating is crucial to the ET process.