Impact study of new cloud and radiation treatments on extended weather forecasts with the US Navy's global atmospheric model

Clouds and radiation are major components of atmospheric physics. Cloud-radiation interactions greatly impact energy balances, and profoundly influence the general circulation of the atmosphere. Accurate representation of radiation and cloud processes is therefore essential for quality global weather forecasts. In an effort to improve forecast skill and to develop an improved NWP model for research applications, the high-order accurate Fu-Liou radiation transfer model and new diagnostic cloud schemes for convective and stable clouds have been implemented in the US Navy operational global atmospheric prediction system (NOGAPS). The new algorithms have been extensively evaluated against observations and reanalyses by investigating their impacts on extended 5-10 day weather forecasts. The combination of the new cloud radiation treatments yields forecast improvements in areas of vigorous convection, including the Tropics, subtropical, and midlatitude storm track regions, where forecasts of hurricane tracks and other storm movements are critical for Navy missions. Details of numerical experiments on high-impact cloud events and semi-real-time weather forecasts will be presented at the conference.