Whether the cold snap is just going to be a light dusting of the white stuff or whether this really is the beginning of the final Snowpocalypse, it seems like a good time to brush up on those winter driving techniques...
Preparation, preparation, preparation
The first thing to do is make sure your car is ready for any serious weather. Tyres are critical here, so make sure you've got plenty of tread depth and that your pressures are correct all round. Winter or all-season tyres are helpful, most certainly, but they're not strictly necessary. You can still get home on your regular rubber if you're careful.
Next make sure all of your lights (heads, tail, indicators, fogs, sides) are all working properly and all lenses are clear. Make sure you've got plenty of screenwash in the reservoir (topped up with extra detergent to help it stop freezing) and maybe a spare bottle of the stuff stashed around somewhere. Oil and anti-freeze checks too, please.
Then you need to make sure you're ready. Warm coat and gloves, and a woolly hat. Heavy-duty boots. Maybe a small shovel. Some food (chocolate or cereal bars are best because they keep) and some water, maybe a flask of hot tea or coffee. A tow-rope, a torch and a warning triangle and you're good to go. Oh wait, you'll need to make sure your phone is fully charged, and maybe bring a spare battery (or charge cable most likely) for that and for your torch, and maybe some Snow Socks and maybe...
Is your journey really necessary?
If it's not, just stay at home. Seriously. If the snow is really bad and if things are starting to ice up, don't go out unless it's really, really necessary. If it is, then play smart - keep away from heavy traffic times (because there's nothing better for a bit of gridlock than snow) and try and stick to main roads and motorways as much as you can, because those will hopefully have been gritted and salted. Minor roads and country back roads are going to be in a far worse state, so avoid them if you can and try and stick, if it's at all possible, to lower-lying coastal roads as these will be the last to freeze up.
It's a good idea to bring a map (a proper paper one, don't rely on a satnav or your phone) in case you need to find a route around snarled-up traffic or impassable routes. Remember, if the Gardai are out and are warning you of problems on the road ahead, they're usually not kidding around. Follow their instructions and don't assume it'll all be fine for you.
Take it gently
If you are going out there take it slow. Really slow. And leave lots and lots of space between you and the car in front. No, more than that. Still more. There, that's about right.
Basically, what you're dealing with here is a lack of friction necessary for your tyres to find grip and traction. Traction will get you going, grip will help you steer and stop, and both are in short supply. So, if you've got a manual gearbox, start off in second and use a higher gear than you normally would on a given road to minimise possible wheelspin. Yes, this helps even with traction control, which is a reactive device stopping wheelspin once it starts. Staying in a higher gear stops the wheelspin before it happens, which is better.
Now for your driving style. Think like Jackie Stewart rather than Lewis Hamilton - everything has to be smooth and gentle. If you upset the car by jerking the wheel or stamping on the pedals, then it's going to react more harshly and harsh movements become amplified when you're on snow or ice. Keep everything on the down-low and you won't upset the car's balance as much, so things will stay more steady.
If you start to slide, turn the wheel in the direction that the car is sliding and don't brake or accelerate. Hopefully, the car will recover some grip, at which point you need to straighten up and then brake very gently to regain control. If you feel a pulsing or vibration when braking that's good - it just means your anti-lock brakes are working properly.
If you get stuck, don't try and use power to get out of it as that won't work. Gently back up (if it's safe to do so) and have another, gentle, go at it. If that doesn't work try using your floor mats to help the wheels find traction or gently rock the car on the clutch to help ease yourself forwards. Snow Socks (soft covers that slip over your tyres to help you find extra traction) can be useful but they're for low speeds only. And don't be the silly person who puts them on the rear wheels of a front-wheel-drive car or vice versa. You're not allowed to fit snow chains as the road safety legislation in Ireland says they're illegal. Generally, snow never gets deep enough here for them to be useful anyway.
Drivers of four-wheel-drive vehicles need to park their confidence - 4WD is good only for finding traction, and once you're moving, an SUV or a 4x4 is no better at stopping and steering than any other car; worse, in fact, thanks to the extra weight of the all-wheel-drive system. Don't assume that the 4WD makes you invincible.
If it all goes wrong and you do end up sliding off the road, try and stay calm. Hopefully, you'll have been going slowly enough that the damage won't be serious. It's OK to get out and have a look and see if you can get going again, but please don't abandon your car and try and get home on foot. First off, you're putting yourself in danger of slipping and falling and really hurting yourself, or worse - being clobbered by a car whose driver couldn't see you in the snow. Stay with the car and call for a recovery truck. The waiting period for one is what the chocolate and flask of tea are for, but don't be too tempted to start a long session of Angry Birds on your phone as you might need the battery life for actual phone calls.
Safe arrival
Assuming you get home OK, be aware of where you're parked and how the weather might affect the car tomorrow (are you parked on or near a steep hill? Are you confident that you can get up or down it safely if it freezes up overnight?) and make sure that you top up things like washer fluid and check your tyre pressures again. Don't forget that you'll have to clear the snow off your car before setting out again (don't be one of those eejits who drives around in a mobile igloo...) so keep a soft brush and an ice-scraper handy too. And don't forget to ring your mum. It's snowing out and she'll want to know that you're OK...
Further reading: How to de-ice your car