# What does AO2A in the remarks of a METAR mean?

I am familiar with AO2 in the METAR remarks as described in this answer, which means the station is automated and has a precipitation discriminator. I have noticed sometimes there is AO2A in the remarks now as in this METAR:

KBAD 171406Z 17012KT 10SM OVC004 18/17 A3002 RMK AO2A SLP168

How is AO2A different from AO2? I assume it is probably some additional capability.