LAPS/RAMS. A nonhydrostatic mesoscale numerical modeling system configured for operational use

Abstract

The National Oceanic and Atmospheric Administration Forecast Systems Laboratory (FSL) has configured an operational local-domain analysis and forecast system designed to function in the local weather office on an inexpensive computer workstation. The real-time system utilizes the 10-km grid increment analyses from the Local Analysis and Prediction System (LAPS) to initialize the Regional Atmospheric Modeling System (RAMS) mesoscale forecast model. A unique aspect of the LAPS/RAMS operational system is the initialization of the high-resolution model with comparable high-resolution analyses. The aim of the LAPS/RAMS real-time system is to provide local-scale guidance to the local weather office in addition to guidance that is currently available from coarser resolution, large-domain operational products. The operational system configuration and the utilization of three-dimensional visualization to display system output is discussed. All components of the LAPS/RAMS system are designed to run efficiently on a computer workstation affordable to individual weather forecast offices. Model validation results suggest that the LAPS/RAMS system is capable of resolving meso-β-scale, often terrain-forced, flow patterns. The three-dimensional visualization of the model output allows the operational forecaster to rapidly peruse the enormous amounts of data and aids the meteorologist’s ability to comprehend and conceptualize mesoscale weather events. Potential improvements to the system are being implemented as computer workstation capabilities increase, which should lead to valuable forecast guidance of meso-γ-scale weather phenomena.