A lovely snippet from one of my favorite aviation bloggers, Aviatrix Canada:
A before-bed weather check reveals:
METAR CYLL 240500Z AUTO 31012G19KT 9SM -RAUP OVC007 01/00 A2967 RMK SLP071 MAX WND 31019KT AT 0454Z
The AUTO group indicates that human observers have gone home and robots are doing the reporting. The -RAUP group indicates that the robots have observed light rain and unknown precipitation. I always like to imagine for a moment that that it means a biblical plague like frogs or anvils or blood, but so far it never has been. The unknown is probably snow or related white frozen precipitation. Stupid robots. Stupid weather.