Handling the risk of winter winds is the same as for dealing with darkness: Be aware that it's a risk, and set limits on your flight operations to minimize the risk.
Fog
In most areas of the country, winter weather brings more fog. As you know, fog is usually caused by a contrast in temperatures. Warm air over cold ground can do it, as can cold air and warm surface temperatures. Winter brings plenty of both conditions.
Fog occurs year-round, but winter fog is often much more widespread than the local patches that develop in the warmer months. One of the most common widespread occurrences of fog happens over the Plains and is called upslope fog. The Great Plains gradually gains elevation west of the Mississippi River, reaching more than 1,300 feet in Wichita, Kansas, more than 3,000 feet in western Kansas, and more than 6,000 feet by the foothills of the Rockies. In the winter, warm moist air can be transported westward and, as it climbs with the terrain, the air becomes saturated and fog forms, creating near zero visibility conditions for hundreds of miles.
Forecasting fog — particularly the time fog will dissipate — is notoriously difficult. Very slight changes in air temperature or wind direction can send the fog packing, or cause it to linger.
The only way to minimize the risk of flying on foggy days is to be totally suspicious of the terminal forecast at your destination airport, and alternate airport, and load on lots of extra fuel. Forecasts will be updated frequently on foggy days, so it's vital to monitor those changes and look for trends. Forecasts made before sunup are particularly unreliable, so if you are making an early morning departure, be especially conservative with your flight planning and alternate airport choice.
Flying an instrument approach in foggy conditions is challenging because you never really "break out" of the clouds into decent visibility. An approach-light system with its flashing "rabbit" lead-in strobe is particularly important in the fog because, as you near decision height, the lights sort of ooze into view and you can continue down the ILS seeing the required runway environment lights.
Low Ceilings
Low clouds are fog moved up a few hundred feet into the air, and they are also much more common in winter. The big difference is that there can often be very good visibility below the cloud ceiling.
Low uniform ceilings are most common over the broad middle of the country and are typically the product of a temperature inversion. An inversion is a layer of warmer air that has overrun the cold air below.
The issue for pilots with low ceilings and inversion is that the conditions can be very widespread and persistent, often lasting all day or even for several days. The clouds are frequently lower than the minimum descent altitude on many nonprecision approaches, so airports without an ILS or GPS LPV become unusable.
Low ceilings with good visibility at the surface are in some ways even more hazardous than fog, because we are tempted to cheat on minimums. With foggy conditions, flying lower doesn't make anything better, but with a low ceiling and good visibility, we know that if we just descend another couple hundred feet we will break out into good conditions. It takes strong self-discipline to stay at the MDA when you know the runway is just ahead and the visibility would allow for an easy landing if you could just get down below the clouds.
To avoid the potential trap of low ceilings, the only answers are very generous fuel-reserve planning and excellent IFR flying skills so that you nail all approach altitudes exactly to give yourself a safe chance of making the landing.
Snow
Snow is a serious winter flying hazard because it can be difficult to forecast and because it cuts forward visibility to near zero.
Snow showers are a particularly potent problem for pilots flying VFR, because their formation and location is impossible to predict with accuracy. The best the forecasters can do is indicate that the conditions are present for snow showers to form, but when and where that will happen is nothing more than a guess.
So-called instability snow showers are potentially the most hazardous to VFR pilots because they occur in otherwise excellent flying conditions. After a weather system moves on, the air behind is often cold, clear and crisp — and unstable. In this case, "unstable" means the air is cooling rapidly with altitude. Because the air is unstable, the warmer air near the surface rises rapidly. In the warm months, thunderstorms could form in such conditions, but in the winter, the small amount of moisture available is literally wrung out of the rising air in the form of snow showers.
