The Mesoscale Analysis and Forecasting Group is involved in a wide-ranging research program to understand and predict atmospheric mesoscale and synoptic phenomena, ranging from large-scale frontal and storm systems to orographic features of scales ranging from one to hundreds of kilometers. The group makes use of high-resolution mesoscale models, such as WRF, and modern observational tools to delineate atmospheric structure and dynamics. Use of mesoscale ensembles for probabilistic prediction and data assimilation is another major project, as is determining the regional implications of global climate change.
A major group project has been to run MM5 and WRF for extended periods forced by global climate models in order to determine the regional implications of global warming. This figure shows the predicted change in winter surface temperatures between the 1990s and the end of the 21st century.
High-resolution MM5 and WRF simulations, down to 1.3 km grid spacing, are being used to understand the structure and origin of orographically produced weather features. This image show simulated winds exiting the Columbia Gorge, the only near sea level gap across the Cascade Mountains. Note the strong winds developing over the western exit.
An important activity of the group is to run a real-time WRF and MM5 mesoscale prediction system down to 4-km grid spacing. This modeling system serves as a platform for testing model improvements. This image shows a three-hour precipitation forecast from a small portion of the 4-km domain.
Improving model physics is a major group activity and one important effort has been the IMPROVE-2 field program, directed towards understanding and correcting deficiencies in model moist physics. These images show winds and reflectivity from the NOAA-P3 aircraft during the December 13-14, 2001 storm over the central Oregon Cascades, with winds on the left and reflectivity on the right. Such information helps determine whether the model simulated the basic state fields correctly and the locations of precipitation. IMPROVE-2 research is ongoing.
The group maintains two different mesoscale ensemble systems for studying probabilistic weather prediction and data assimilation. This image shows precipitation from six members of the UWME ensemble prediction system.