Arch Coal (NYSE:ACI) is warning that its Q4 results will be affected by negative developments in its operations. The company said this is due to reduced production and shipment levels. Specifically, the former saw a quarter-over-quarter drop of 40% at its Mountain Laurel facility in Appalachia, resulting from what the company described as "challenging geologic conditions in the current longwall panel." 

For the latter, a decline of over 15% on a quarter-over-quarter basis was recorded in Arch Coal's Powder River Basin mines. The company attributed this to difficulties with its rail service.

As a result, the company said its full-year 2013 metallurgical coal sales volumes came in a bit below the lower end of its expectations.

Arch Coal is scheduled to release its Q4 earnings before market open on Feb. 4. Analysts are projecting a per-share loss of $0.33 on revenues of $816 million. Those figures for Q4 2012 were a loss of $0.42 per share and $968 million, respectively. 

Fool contributor Eric Volkman has no position in Arch Coal. Nor does The Motley Fool. Try any of our Foolish newsletter services free for 30 days. We Fools don't 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.