Darwin in december : WEATHER

Hi everyone,

First, excuse my english, it's terrible.
I'm French (that explains my terrible english...) and I'm meeting my sister and her boyfriend next week in Darwin, on december 1st. I'll take a plane from Sydney and they are going to drive from Cairns. We are not sure about the roads safety, I mean with the weather there is a risk of flooding all over the roads. Do you know anything about it ? And I don't know about the current weather in Darwin, if anybody is there, can you tell me if it's bad because the weather channel says it is... And I'm not sure it is worthy to come and visit the city and the Kakadu national park under rain and storms...
Thank you for your answers...
Juline