A prototype system called the Areal Vicinity Icing and Snow Advisor (AVISA) was recently developed at the Meteorological Service of Canada. The purpose of AVISA is to combine remotely sensed data in near real time in order to estimate in-flight icing potential and snowfall hazards near an airport such as Mirabel. The AVISA system was tested during the winter of 2002-03 during the Alliance Icing Research Study (AIRS 1.5) field project. AIRS-1.5 was a precursor to AIRS-2 which is a significantly larger research program scheduled for the winter of 2003-04. Various column oriented instruments such as a vertically pointed microwave radiometer, McGill University’s vertically pointing X-band radar (VPR), a Precipitation Occurrence Sensor System (POSS), a hot plate snow gauge, and standard met station instruments were deployed on the ground at Mirabel during AIRS 1.5. In-flight icing conditions were validated in some cases by instrumented Convair-580 flights above the ground site.

A significant issue for AVISA is to infer icing conditions not only above the ground site, but also in the near vicinity. One source of horizontal spatial context typically used in icing studies is GOES satellite imagery. However, the native GOES-IR resolution of 4 kilometers is coarse relative to the vertically pointed instruments on the ground. Multi-layer cloud features are often difficult to resolve by satellite. Using inferences from a combination of sensors including GOES satellite products, an improved estimate of cloud layers and cloud top height can be obtained. A case from AIRS-1.5 is described.