HR: 11:15h
AN: A42A-04    [Abstracts]
TI: Improving Regional High-impact Weather Forecasts with a High-resolution Cloud-resolving Numerical Model
AU: * Liu, A
EM: liuqi@atmosp.physics.utoronto.ca
AF: University of Toronto, 60 St. George Street, Toronto, Ont M5S 1A7 Canada
AU: Moore, K
EM: moore@atmosp.physics.utoronto.ca
AF: University of Toronto, 60 St. George Street, Toronto, Ont M5S 1A7 Canada
AU: Maesaka, T
EM: maesaka@atmosp.physics.utoronto.ca
AF: University of Toronto, 60 St. George Street, Toronto, Ont M5S 1A7 Canada
AU: Tsuboki, K
EM: tsuboki@rain.ihas.nagoya-u.ac.jp
AF: Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Japan
AB: High impact weather is one of the greatest threats to human society, while an accurate forecast of these events remains a challenge for current operational models. Very often the temporal and spatial evolution of these high impact weather systems is dominated by small convective-scale motion and complicated microphysical processes. For improvements in the forecasting of such weather systems, a high-resolution cloud-resolving model with improved model physics is required. In this study, a cloud-resolving mesoscale forecast model, the Cloud Resolving Storm Simulator (CReSS), was employed to simulate observed cases lake-effect snowstorms, an important source of high impact weather over the Great Lakes region. One of the challenges in simulating these events is a correct representation of the cloud-scale processes that result in the quasi-2-dimensional clouds that are characteristic of these storms. The simulation had a very high spatial resolution, 500m in the horizontal and a stretched vertical grid with a minimum spacing of 30m, and was run in a domain of 800 km by 650 km that encompassed much of the Great Lakes region. Such a simulation remains a computational challenge and we made use of CReSS's efficient parallelization capabilities to complete the simulation using 880 CPUs on the Earth Simulator. The 8-hour simulation was completed in 2.67 hours and CReSS attained a sustained rate of 1.6 Tflops. The model simulated results are in good agreement with the field observations from the Lake-Induced Convection Experiment (Lake-ICE), in particular, the model explicitly resolved the convective roll clouds, which is crucial for the model to successfully represent this high impact weather event. Indeed, synthetic radar data derived from the model's hydrometeor fields was in good agreement with observations. The results of this study highlight the improvements in regional-scale forecasts that can be made with cloud models.
DE: 3314 Convective processes
DE: 3329 Mesoscale meteorology
DE: 4540 Ice mechanics and air/sea/ice exchange processes
SC: Atmospheric Sciences [A]
MN: 2005 Joint Assembly