In its recently released monthly performance report, UP said it loaded 842 coal trains in the Southern Powder River Basin last month, down from 1044 trains in 2011.

The company’s totals have been on a downward slide since the beginning of the year after kicking off 2012 with 1022 loadings in January versus 1056 in the 2011 comparable period.

Shipments from UP’s other main service area, the Colorado/Utah region, were also on the decline.

It loaded 195 coal trains in March, versus 230 in the previous corresponding period.

UP cited two primary factors for its results, the first being an ongoing slump in the coal market after a mild winter left many with higher stockpiles.

Severe weather was also an obstacle, albeit minor, due to a strong storm system that left heavy rain, flooding and hail across portions of Kansas, Oklahoma, Texas and Lousiana in the company’s southern tier and caused mainline track washouts.

Additionally, minor damage was reported after a tornado hit its Bailey Yard in Nebraska and before the month was out, its mainline near Spokane in Washington was out of service following a mudslide.

UP is currently detouring trains heading for the Canadian Pacific interchange in Idaho via St Paul in Minnesota and over Burlington Northern Santa Fe routes while it conducts a week-long project of clean-up and track repairs.

Earlier this month, UP chief financial officer Rob Knight said the shipper was projecting a 7% drop in first-quarter coal shipments due to the mild weather.

He told guests at the JP Morgan Aviation, Transportation and Defense conference that while shipments were lagging, shipping volumes had risen to date this year.

However, UP maintained its optimistic full-year profit forecast as the economy began to recover.

“Coal inventory levels are up and the burn rate is down,” he said, according to Reuters.

“What will change that glide path are summer conditions.”

Utility customers were averaging 75-day inventory stockpiles, the executive told the news service.

Optimal levels average about 60 days.

UP’s operation area encompasses 23 states in the western two-thirds of the US.

BNSF and UP are the two largest shippers for the western coalfields.