Atis RVR abbreviation?

[protect essential]

Recently saw this abbreviation on Atis: 650D and 700N. What does the "D" and "N" mean?? BTW, this was in China

Thanks.

[Mohit_C]

I understand it as RVR of 650 metres with a tendency to decrease(D) and RVR of 700 metres with a tendency to not change/stay constant (N).

[Green Guard]

that was in China ?

I would believe, if it came like :

六百五十減少，七百沒有變化

[BOAC]

Pong Mahjong!

[zonnair]

and U = for tendency to increase

[ron83]

D= Downward tendency
U= Upward tendency
N= Neutral tendency