Weather has an obvious impact on aviation safety in the terminal environment. The weather factors that affect terminal operations, however, are often of limited extent - horizontally and vertically - and duration (e.g. the AA1420 crash at Little Rock, AR in a Level 6 storm). This makes the forecasting of these features extremely difficult. Compounding the forecasting problems is the typical siting of airports. From a safety (of ground based personnel and assets), noise abatement, and zoning issues, the easiest place to put an airport in many instances is near a large body of water. Of the 25 busiest US airports by passenger volume, almost half are near significant bodies of water. This same water often provides the moisture necessary for significant radiation, advection, or orographically forced fog or clouds to form, hampering terminal operations.

The Operational Multiscale Environment model with Grid Adaptivity (OMEGA) is an atmospheric simulation system designed around an adaptive unstructured grid. The adaptive grid of OMEGA permits the true multiscale simulation or forecast of small spatial or temporal scale features in the atmosphere. OMEGA is used for research and operational forecasting of multiscale phenomena from aerosol and gas dispersion to hurricanes. As a demonstration of the ability to predict oceanic convection, SAIC performed a retrospective OMEGA forecast of a case from the Genesis of Atlantic Lows Experiment (GALE). In particular, we simulated the cold air outbreak during the GALE IOP-2 (January 26-28,1986). A computational grid with horizontal resolution ranging from 20 km to 60 km and a vertical resolution ranging from 15 m near the ground to 1 km at the top of the domain was used. The figure shows a close-up of the OMEGA predicted deep cumulus cloud cover after 24 hours of simulation with the data from the lightning network overlaid.

This paper will present a quick overview of the OMEGA system as applied to aviation weather including enroute (convection) and terminal (ceiling and visibility) problems.