Based on a chronology posted ^^^, the conversation between IB, BA, and Boston Tower occurred between 2320 and 2325 hours. The Metars covering that period are:
METAR KBOS 022254Z 22004KT 5SM -SN OVC025 M03/M11 A3024
SPECI KBOS 022340Z 21003KT 1 3/4SM -SN BKN025 OVC060 M04/M09 A3023 RMK AO2 P0000
The special observation reporting visibility as 1 3/4 with light snow was made 15-20 minutes after the pertinent conversation; 25-30 minutes prior to the conversation, the regular Metars reported visibility as 5 miles in what would be very light snow.
As the temperature at 2340 is -4C and the dewpoint is -9C, the light snow that was falling was almost certainly fluffy and unlikely to be adhering to surfaces.
The total snowfall measured for KBOS for all of December 2 was 0.3 inches.