Once a year, I drop everything to trek to the great white north in search of dazzling winter landscapes and rugged ski terrain. I'm not a particularly adept skier and rarely venture out on anything more challenging than the blue trails. For a snow-starved Louisiana native, though, simply playing in a freshly fallen blanket of white makes the entire trip worthwhile. Unfortunately, assuming the weather forecasts are accurate, I will be slipping down the slopes of Northern Montana tomorrow in blinding rain and temperatures nudging 50.

At least packing should be easy; I'll replace my bulky ski clothes with a light rain jacket.

In hindsight, maybe Lake Tahoe would have been a better choice, where Vail Resorts' (NYSE:MTN) Heavenly Valley is reporting base snow depths of up to 14 feet. Many resorts across the West have been positively giddy lately since the region has been bountifully buried in fresh powder. Mother Nature can indeed be capricious, blessing some companies one week and then wreaking havoc on others the next -- though the latter seems to be a more common occurrence. Occasionally, it can even do both to one company simultaneously.

Last week, The Sports Authority (NYSE:TSA) announced that many of its winter product lines were tracking below expectations, particularly in select markets where Old Man Winter was sleeping on the job. In the words of CEO Doug Morton, sales "did not materialize, as these markets experienced significantly less snowfall amounts than normal." As a result, fourth-quarter same-store sales -- which were previously expected to come in flat -- are now projected to drop 2% lower. Furthermore, earnings have been scaled back from $1.08 to a new range of $0.90-$0.95.

The dour news, though, was tempered somewhat by predictions that heavy post-Christmas snowfalls would be the ideal catalyst to get sluggish sales moving forward again in January. Investors applauded that silver lining, overlooked the whole "earnings and comps aren't looking too good" portion of the press release, and sent the shares higher by double digits last Thursday.

However, there wasn't much of a forgiving mood at Gander Mountain (NASDAQ:GMTN), which met with a rather hostile response after announcing similar, albeit gloomier, news. The camping and outdoor specialist -- again citing the impact of "unseasonably warm weather" -- plunged 17% after slashing fiscal 2004 pre-tax earnings guidance to $2-$4 million from an already reduced $8-$13 million. Fourth-quarter same-store sales, after jumping 12.2% last year, are now expected to drop by 6%. Like The Sports Authority, the company reported a pickup after the holidays, though it was partially attributable to margin-munching promotional activity.

Both companies have been sloping downward lately toward the bottom of the 52-week mountain and could use a little help to climb higher, but I wouldn't rely too heavily on cooperation from the skies. Despite the sophistication of modern meteorological modeling techniques, forecasting the weather can at times still be completely unpredictable. Some would say the same holds true in the financial world. Trying to assess an earnings outlook based in large part on the weather, then, would seem to be an inexact science at best.

Here are a few more trails you might like to follow:

If it does rain, Fool contributor Nathan Slaughter is planning to cross the border into Canada in search of colder air. He owns none of the companies mentioned.