It happens, but on a rare occasion. "Thunderstorms do occur more often in Spring/Summer because the conditions are more favorable for their formation then. A thunderstorm forms when air can be "convected" easily; in other words, when the rate of temperature decrease with height (called the temperature gradient) is large. This occurs during warmer weather because the ground is warm. Energy and water vapor are released from the warm surface and rise in buoyant plumes, which, when combined and organized, form a thunderstorm cell. In the winter the temperature gradient with height (and with horizontal distance as well) is smaller and weather systems are proportionately weaker. Sometimes a thunderstorm will occur in winter, embedded in a cold front where the air tends to be rising more strongly. However, the air cannot rise as rapidly because of the small vertical temperature gradient and rarely produces a strong thunderstorm. Lightning occurs only in thunderstorms, which are rare during winter in the northern part of our country. Lightning can occur only because rapidly rising and falling water droplets and ice crystals in thunderstorms cause electric charge to be created and accumulated in different parts of the thunderstorm. More charge is created in stronger thunderstorms, few of which can be formed in winter; thus little lightning in seen in the winter. David R. Cook"

Uh, yes it can most certainly happen. When it does, it is absolutely fantastic! I have a name for them: Thunderblizzards! The first one I ever witnessed was in 1979 in Norfolk, Nebraska sometime after midnight. I was driving my old Honda Civic westward on Norfolk Avenue (main street) to hit the 24-hour grocery for some snacks. There was the beginning of a huge, dangerous blizzard (the reason why I was stocking up on munchies). The sky lit up with some jagged lightning strikes, but obscured slightly by the driving snowflakes. When I got to the grocery store, I just stood underneath the awning watching and listening. The thunder was very deep, but muffled. The ground shook with its force. It's an experience I'll never forget. That thunderblizzard lasted over 30-minutes before only hard snow was apparent. The second one was six years ago during my walking commute home from work at 5am. The snow had started as flurries, then moderate snow. Suddenly, the wind picked up (for a moment I thought there could even be a tornado...but no funnel cloud that morning) and there was, what appeared to be, sheet lightning (hard snow obscuring the bolts--I'm sure). The thunder was present and echoing between the buildings in the downtown business section of town...somewhat muffled but still it was unmistakeable. I saw a police cruiser, it pulled over. The cop and I stood underneath an awning of a thrift store. We were both in complete awe. All we could do was stand there with our mouths open wanting to try to explain what we were seeing. It is approaching that time of year when there might be a good chance of witnessing another thunderblizzard...I hope we have another one soon, even though they are very frightening. You haven't lived until you've experienced this!

There are two reasons thundersnow is rare: 1. The moisture column with associated cold temps and precip is not near as deep as a typical thunderstorm seen in the warmer months. Cold air holds less moisture than does warmer air thus the atmosphere is too dry for clouds to build very high which is crucial to get lightning. 2. Also, cold air is subsident which means it's constantly trying to fall to the surface. As the cold air rushes to the surface, pressure increases placing that location in high pressure which if you pay attention to your local meteorologist means very little chance for precipitation. To add to reason number 2, warmer air does just the opposite of cold air. Warm air rises. That's the reason people float in hot air balloons and not cold air balloons. Here's what CAN cause thundersnow: -There has to be nearly 100% relative humidity in the low levels. -The temps in the low levels have to be on the borderline of rain/snow to hold as much moisture as possible. -There has to be a very strong trigger for these storms which is usually along a frontal boundary. This allows winds to converge at the surface then build into the mid levels of the atmosphere.

There is thunder when it snows, and it is rare. They're called "Squall Lines". They're lines of snow that hit an area at a fast speed, and they can cause thunder, and I think even sometimes lightening, but that's rare. This has happened twice to me. I freaked out because I didn't think it could thunder during snow(plus, when I was younger, thunderstorms were the #1 thing I feared. Thats why winter was my fave season, no thunderstorms, but that day, it thundered, and I hated winters too!! lol :) )