The forecaster says his will lead to greatly reduced visibilities and poor driving conditions.
The fog is likely to clear only slowly during Thursday.
The Road Safety Authority has also issued advice. Ms. Moyagh Murdock, CEO, Road Safety Authority said: “Heavy fog seriously reduces your visibility and makes driving very dangerous. Our advice is to switch on dipped headlights and fog lamps, reduce your speed and keep a safe distance from the vehicle in front. If the fog closes in, reduce your speed further and take your time getting to your destination. Open your window a little so you can listen out for other road users, particularly at junctions. Vulnerable road users should avoid, cycling or walking in fog unless it is a necessity.”
All road users are advised to listen to weather forecasts and general advice about driving conditions.
The added dangers posed by fog is that a collision involving one vehicle can quickly involve many others, especially if driving too fast and too close to one another. The biggest risk is of a multiple-vehicle pile-up on roads with higher speeds such as motorways and dual carriageways.
The RSA is also advising vulnerable road-users such as pedestrians, motorcyclists and cyclists to ensure they are clearly visible to other road-users by wearing high visibility clothing and using lights.
Other tips for road users include:
• Slow down and increase the distance from the vehicle in front.
• Use dipped headlights and front and rear fog lights, if fitted.
• Open your window a little so you can hear other road users approaching, particularly at junctions.
• Remember to switch off fog lights when visibility improves.
• Keep a sharp lookout for pedestrians, cyclists and motorcyclists.
• Do not blindly follow the vehicle in front – it may leave the road for whatever reason.
• If you have to stop, activate your hazard warning lights.
• Be Seen to Be Safe! Visibility is reduced in poor weather conditions so wear high visibility clothing or carry a torch. As children often journey to school in the dark, make sure your child can be seen.
• Be extremely careful in the vicinity of open water, canals, lakes, ponds or coastal piers etc