New snow has fallen last night in parts of the country. As there is hardly any traffic, there are no real traffic jams.

Schiphol Airport is still dealing with cancellations and delays, also because of snow problems on other airports in Europe.
About a 1,000 people spent the night on the airport.

Trains are running, but delays and cancellations should be expected. There are trains between Amsterdam Central Station and Schiphol Airport, but there are delays, you should take extra time.

Public transport within Amsterdam is functioning, but with delays.

Update 20 December:
Most problems have diminished.
Schiphol is resuming normal flight schedules, but due to problems on other airports there can still be delays and cancellations.
Trains are running mostly with the normal reduced winter schedule, which means there are less trains scheduled than normal.
Amsterdam public transport is running practically normally.
Road traffic is slightly heavier than normal, road can still be slippery, esp. off the highways.