Can I be prosecuted for ignoring a road closure sign during flooding in Northern Ireland?

Yes. Ignoring an official road-closure sign or lawful traffic direction can result in enforcement, and it can also expose you and rescuers to serious danger.

The precise offence depends on the traffic order, sign or police direction in force at the location.

Northern Ireland winter driving is especially sensitive to changing road-surface temperature, rain, ice, flooding and exposed routes. Official advice is to drive for the conditions actually in front of you, not for the posted speed limit or the fact that a road was treated earlier. TrafficWatchNI and current weather warnings are the right live sources when conditions are deteriorating.

For this exact question — “Can I be prosecuted for ignoring a road closure sign during flooding in Northern Ireland?” — the practical point is: Treat the closure as mandatory unless an authorised person directs you otherwise. The answer should be applied to the actual signs, conditions, licence wording or parking rules in force at the time, because temporary restrictions and individual DVA decisions can change the ordinary position.