Using Icing Algorithm Output to Create AIRMETs

AIRMETs (Airmen's Meteorological Information) for aircraft icing are produced at the Aviation Weather Center (AWC) and represent the official forecast of in-flight icing conditions. The AIRMET provides a six-hour forecast of icing conditions and must account for movement and evolution of the icing conditions during that time. The Current and Forecast Icing Products (CIP and FIP) are also run operationally at the AWC. They are used as guidance for the forecasters and supplementary icing information for pilots and dispatchers. The CIP and FIP provide gridded icing snapshots that are valid for one hour and evolve the conditions as observations change and model forecasts update. This paper will describe a method developed at the National Center for Atmospheric Research to use output from the automated icing algorithms to create a suggested icing AIRMET that could then be edited and issued by AWC forecasters. I. Introduction HERE are multiple methods for users to receive forecasts of in-flight icing conditions. AIRMETs (Airmen’s Meteorological Information) and SIGMETs (Significant Meteorological Information) represent the official products and are produced by the Aviation Weather Center (AWC). The Current and Forecast Icing Products (CIP and FIP) are algorithms developed at the National Center for Atmospheric Research (NCAR) and run at the AWC. These products give similar information but in different ways and do not always mesh well together. CIP and FIP provide more details about the icing conditions than an AIRMET, but an AIRMET is more familiar, quicker to view, and easier to understand in some cases. Using the CIP and FIP to create a suggested AIRMET region would serve to take advantage of the extra detail the algorithms provide and make it easier for forecasters to generate AIRMETs by highlighting potential regions of focus. In this paper we will describe current icing products including AIRMETs and CIP/FIP, introduce a method to use icing algorithm output to produce an initial AIRMET, and describe how this method could be used and tested at the AWC in the Aviation Weather Testbed (AWT).