For many of us across the United States, this winter has been relatively mild. Warmer-than-normal weather has blanketed much of the country, leading to a reduction in energy demand and a huge buildup in natural gas supplies.

For those on Wall Street, portending weakness in the natural gas market seemed easy to spot with the huge recent reserves discovered in the United States. Compound an overabundance of supply with little need for demand from the warmer weather and you have a recipe for decade-low prices.

But not everything is this obvious. There are alternate sectors not in the forefront of investors' minds that very well could be feeling a margin pinch when it comes time to report their quarterly results. What I intend to do is look past the obvious and point to two sectors that could be in for a temporary rough patch because of the warm weather.

Winter recreation
Entertainment and leisure have their give-and-take. Whereas warmer weather leads people to spend more at restaurants, it could be a serious deterrent to Vail Resorts (NYSE: MTN).

Back in early January, Vail Resorts released ski data from its six resorts that showed that overall season-to-date skier visits were down a whopping 15.3%! The drop, attributed even to season pass holders, shows that if the snow isn't there, then neither are the skiers. Vail is already trading at a lofty 71 times trailing-12-month earnings, so this is definitely not good news.

Another troublesome statistic could come from snowmobile producers Arctic Cat (Nasdaq: ACAT) and Polaris Industries (NYSE: PII) in the coming quarters.

Arctic Cat recently reported a 61% jump in snowmobile sales, but it's also dealing with its second batch of snowmobile recalls in just three months. With the stock at a new all-time high, it may not take much of a drop-off in snowmobile sales to curtail its rapid advance.

Polaris and Arctic Cat both have an extensive line of ATVs as well, so it's not that they're intrinsically tied to just snowmobile sales -- but those sales do play a pivotal role in bottom-line results. Polaris recorded a 63% jump in quarterly snowmobile sales over the year-ago period, and snowmobiles comprised 22% of all fourth-quarter sales.

Transportation
In a real-life case of the goldfish getting eaten by the cat and the cat choking on the goldfish, low natural gas prices are causing electric utilities to opt for the switch from coal to natural gas to generate electricity. While this might be great news for consumers and green-energy advocates, the railroad industry is beginning to feel the pain of this switch.

Railroad Genesee & Wyoming (NYSE: GWR) relies on transporting coal to drive its bottom line. As more utilities have switched to lower-cost natural gas, Genesee's demand has fallen. Just two days ago, the company reported a 12% nosedive in total carloads driven by a 40% drop in total coal shipments.

This problem isn't just limited to railroad transporters, but also railcar producers. FreightCar America (Nasdaq: RAIL) tumbled this week following an analyst downgrade as well as in response to the news from Genesee & Wyoming. Since natural gas is transported via pipeline, there will presumably not be much demand for railcars in the near term.

Foolish roundup
Sometimes it's amazing how quickly you can get to "six degrees of separation" in the stock market. Whether or not these stocks are showing the effect of a warmer winter now, it pays for shareholders to take note of these trends and to adjust their investment thesis accordingly.

Are there any companies I've left out that you think could be adversely affected by the warmer weather? Share them in the comments section below and consider adding these five stocks to your free and personalized watchlist.

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