The Influence of Shallow Convection on Tropical Cyclone Track Forecasts

• DOI: 10.1175/mwr-d-11-00246.1
• Publication Date: 2012-02-09T22:38:12Z
• Authors: Ryan D. Torn; Christopher A. Davis
• Keywords: Typhoon

ABSTRACT Accurate tropical cyclone (TC) track forecasts depend on having skillful numerical model predictions of the environmental wind field. Given that and temperature are related through thermal balance, structural errors in processes determine profile, such as shallow convection, can therefore lead to biases TC position. This paper evaluates influence convection Advanced Hurricane Weather Research Forecasting Model (AHW) by cycling an ensemble data assimilation during a 1-month period 2008 where cumulus is parameterized coarse-resolution domain using Kain–Fritsch scheme or modified Tiedtke scheme, which contains more appropriate treatment oceanic convection. Short-term with characterized 1-K, 700-hPa bias over much western Atlantic Ocean, attributed lack within scheme. In turn, horizontal gradients this associated region multiple TCs move period. By contrast, does not suffer from bias, thus smaller. AHW initialized system uses have up 25% smaller than Kain–Fritsch.