Panera (NASDAQ:PNRA) warned that its first-quarter earnings might not be so hot, considering that inclement weather weighed on its profitability.

Although Panera's first-quarter revenues rose 24%, the cafe operator said that its earnings will be at or "modestly below" its previous guidance of $0.47 to $0.50 per share. This is due to comp sales in the low range of its previous estimate, as well as dampened margins caused by the "extreme weather" in some core markets.

Panera said that when its comps are hit by weather, that has a significantly higher impact on earnings given the inability to rapidly reduce food and labor. Of course, it's really hard for investors to feel all that sympathetic about the weather excuse. (Granted, other casual dining chains have also said bad weather was a recipe for a tough first quarter.) After all, since weather happens and it happens to all retailers, it's pretty much a no-brainer that it's going to disrupt business in certain markets. Honestly, though, it made me wonder if Panera's business is a bit more weather-sensitive than other restaurants and cafes, since the company provides fresh-baked bread daily.

Panera's Form 10-K filing does outline related points, since it says it depends on frequent deliveries of ingredients. Three companies deliver the majority of its ingredients to its cafes on a regular basis (two or three times weekly). Plus, Panera has local and national suppliers that it says deliver produce three to six times per week, and that channel is particularly vulnerable to weather-related supply volatility. In addition, Panera's fresh dough facilities deliver fresh dough daily. It's easy to see how disruptions could occur, or lots of fresh bread or dough could go to waste when customers don't show up.

At any rate, Panera's got plenty of issues to watch. Management previously said they expected better fortunes in the second and third quarter of this year, but a possibly worse-than-anticipated first quarter isn't too terribly heartening. Panera has already said that this year it plans to work on further differentiating itself from the competition and more effectively draw in lunch crowds. That's no small feat, considering it faces all kinds of formidable competitors, like Starbucks (NASDAQ:SBUX), McDonald's (NYSE:MCD), and Chipotle Mexican Grill (NYSE:CMG), to name a mere few, all of which want to draw lunch crowds too.

I'd say there's still reason for some caution on Panera. The company does have its work cut out for it this year, and although it has previously spoken optimistically about the second and third quarters, it probably shakes investors' confidence that the first quarter sounds a bit more subdued than previously expected. There are many elements investors should consider if they're thinking about loading up on Panera.

Slice yourself some related Foolishness:

Starbucks is a Motley Fool Stock Advisor pick. Chipotle Mexican Grill has been recommended by both Motley Fool Rule Breakers and Motley Fool Hidden Gems.

Alyce Lomax owns shares of Starbucks. The Fool has a disclosure policy, come rain or shine.