Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of discount airline Spirit Airlines (NYSE:SAVE) are losing altitude today by almost 6% following release of its fiscal-first-quarter results.

So what: Revenue jumped 18.2% to $438 million, a hair higher than analyst expectations of $437.9 million. Adjusted net income leaped 15.4% to $37.8 million, or $0.52 per share, also a hair higher than analyst expectations for $0.51 per share. Revenue and presumably net income would have been higher if not for the 256 weather-related flight cancellations during the quarter, compared to just 59 cancellations last year.

Where Spirit Airlines seems to have come up short is on the revenue and costs per available seat mile. Revenue per available seat mile declined 2.4% to $0.11 while at the same time adjusted cost per available seat mile rose very slightly to $0.06 cents.

"Average stage length" and the calendar shift of the Easter holiday were blamed for the revenue per available seat mile decline while "increased number of scheduled maintenance events" were blamed on the lack of an associated decline in costs.

Now what: Ben Baldanza, CEO of Spirit Airlines, was pleased with the quarter given the number of challenges that the severe winter storms caused. He believes that the quarter "provides a firm foundation" as Spirit Airlines grows its business for the remainder of the year. Most likely, the challenges associated with severe weather are over.  

Based on analyst estimates, Spirit Airlines trades at a forward P/E of 19 based upon current share price and estimated EPS of $2.92 for the year ending December 2014, which appears to be a bit pricey compared to many other major and regional airlines.

Nickey Friedman has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.