NEXT-GENERATION NUMERICAL WEATHER PREDICTION Bridging Parameterization, Explicit Clouds, and Large Eddies BY SONG-Y OU HONG AND JIMY DUDHIA THE THIRD INTERNATIONAL WORKSHOP ON NEXT-GENERATION NWP MODELS WHAT: Scientists from Korea, Japan, France, England, Finland, and the United States met to discuss recent developments in the parameterizations of physical processes in next-generation, high- resolution numerical weather prediction (NWP) models (http://nml.yonsei.ac.kr/20100829/). WHEN: 30 August–1 September 2010 WHERE : Seoguipo, Jeju, South Korea S ix years after the second international workshop on the physical parameterizations in numerical weather prediction (NWP) models in 2004 (Lee and Hong 2005), attendees at the third workshop on next-generation NWP models met to discuss progress in high-resolution NWP modeling and share ideas about future challenges. The main theme of the meet- ing was “The Cloud-Resolving Modeling Approach and Beyond.” As of 2010, convection-permitting and cloud-resolving scale modeling has become practi- cally feasible, along with the successful usage of large- eddy simulation (LES) in developing subgrid-scale parameterizations for these models. Many national hydrometeorological centers are now running models in the 2–5-km grid-size range, and will be increasing resolution at a steady rate such that several centers may be at around 1 km in 5 yr. The main topic of the workshop focused on future problems in physics as NWP models go to finer scales where there are “gray zones” in which the explicit model dynamics are almost capable of resolving features that were parameterized at coarser scales. The following ques- tions were posed for the workshop: • At what scales do the one-dimensional (1D) vertical mixing planetary boundary layer (PBL) schemes, which are usually separated from hori- zontal mixing, work? • When do they need to be replaced with three- dimensional (3D) large-eddy-simulating turbu- lence models? • At what scales are models considered to be convec- tion permitting? • When is a cumulus parameterization scheme (CPS) needed? • When is a separate shallow convective scheme needed? AFFILIATIONS : HONG—Department of Atmospheric Sciences, Yonsei University, Seoul, South Korea; DUDHIA—MMM Division, NCAR, Boulder, Colorado CORRESPONDING AUTHOR : Song-You Hong, Department of Atmospheric Sciences, Yonsei University, Seoul 120–749, South Korea E-mail: shong@yonsei.ac.kr DOI:10.1175/2011BAMS3224.1 In final form 24 August 2011 ©2012 American Meteorological Society 1 JANUARY 2012 AMERICAN METEOROLOGICAL SOCIETY |