Mesoscale numerical weather prediction (NWP) has the potential to significantly improve local weather forecasting. The aviation community stands to benefit from the detail afforded by mesoscale models through reduced delays and better preparedness in advance of extreme weather events. The Pennsylvania State University/NCAR (National Center for Atmospheric Research) fifth generation mesoscale model (MM5) is being employed on an ever-growing basis for real-time weather forecasting. Potential users of the MM5 include the aviation community and forecasting agencies such as the National Weather Service, in addition to the university community.
MM5 has shown considerable skill in forecasting mesoscale meteorological phenomena that cannot be resolved by the coarser resolution, hydrostatic operational models. MM5 is extremely flexible and, thus, can be tailored to suit many different applications. However, to realize the full capability of the model, complex and disparate data sources must be pooled to properly represent the atmosphere's initial state, and the user must properly configure the model parameterizations. This complex setup process often makes configuration of the model difficult and tedious, especially in real- time applications where there is little time or room for error.
To alleviate these problems, TASC has developed a graphical user interface (GUI) to be used for configuring and running the MM5. The GUI allows for the consistent configuration of all parameters within the pre- and post-processing modules, as well as the main MM5 module. As an example of the benefits that can be gained by using GUIs to set up an MM5 run, one needs look no further than selecting geographic regions over which to run the model. Without the aid of a GUI, a user must select a center latitude/longitude pair, the number of grid points in each dimension of the grid, and the grid spacing between grid points. Then, the user must run the MM5 terrain module and view the output to determine if the grid is, in fact, in the intended geographic location. Often, the user runs the terrain module many times in an iterative fashion to select and adjust a geographic region. TASC's GUI allows the user to quickly and accurately select the domain and all subdomains by simply "rubber banding" boxes over a graphical map. The geographic region over which the model will be run is displayed while the user is selecting it, ensuring the selection of the correct geographic location on the first try. Various tools allow for the interactive repositioning and resizing of the model domain as necessary.
In this paper, results from an MM5 run which simulates a heavy snow event, an event that was not resolved well by the typical observational models (e.g., AVN, ETA, NGM), are presented. This case illustrates the benefits that aviation weather forecasters stand to gain from employing real-time runs of mesoscale numerical models in their operations. Furthermore, an appreciation of the utility of a graphical user interface in configuring the model is gained by demonstrating how it might be employed in an operational situation.
The 8th Conference on Aviation, Range, and Aerospace Meteorology