Sunshine and swooshing surface hoar

AST2 course with Island Alpine Guides. Back side of Mnt Wash -10c Elevation 1440 Compression test- easy 10 sudden collapse @29cm Extended column test- Moderate 15 sudden planer @29cm 4cm surface hoar 2mm Facets above and below the crust 30cm depth. We had some nice pockets of deeper snow North facing, but still hit crusty spots. Ski cut with no results. SE ridge was wind affected higher up. Mid to lower run, 5cm of surface hoar made for fun, sparkly, swoosh swoosh skiing.