B | Blue |
BA | Braking action |
BASE | Cloud base |
BC | Localizer Back Course |
BCFG | Fog patches |
BCN | Beacon (aeronautical ground light) |
BCST | Broadcast |
BDRY | Boundary |
BECMG | Becoming |
BFR | Before |
BKN | Broken |
BL... | Blowing (followed by DU=dust, SA=sand, SN=snow) |
BLDG | Building |
BR | Mist |
BRG | Bearing |
BRKG | Braking |
B | RNAV Basic area navigation |
BS | Commercial broadcasting station |
BTL | Between layers |
BTN | Between |