I’ve seen remarks in some of the obs. MWN seems to have retained theirs.
I just picked a random date range here but you can see some of the icing and cloud comments in there.
https://mesonet.agron.iastate.edu/cgi-bin/request/asos.py?network=NH_ASOS&station=MWN&data=metar&year1=1984&month1=1&day1=1&year2=1984&month2=1&day2=28&tz=Etc%2FUTC&format=onlycomma&latlon=no&elev=no&missing=M&trace=T&direct=no&report_type=3&report_type=4
Found me some aurbo obs too
MWN,1982-02-02 02:00,KMWN 020200Z 32065G89KT 90SM CLR M13/M16 A//// RMK TOPS LWR SCT 50/AURORA N SLPNO T11271155
MWN,1982-02-02 03:00,KMWN 020300Z 32064KT 45SM CLR M13/M16 A//// RMK SLPNO T11281156
MWN,1982-02-02 05:00,KMWN 020500Z 32052G62KT 90SM CLR M11/M29 A//// RMK AURORA N SLPNO T11101288
MWN,1982-02-02 08:00,KMWN 020800Z 30033KT 90SM CLR M10/M31 A//// RMK AURBO W-N-E SLPNO T10991305