OKLAHOMA CITY (AP) — An icy storm plowing across the country is delaying shipments of everything from Christmas presents to cooking grease.

Wal-Mart had its truckers take extra goods to stores ahead of the storm, while Amazon and FedEx are notifying those waiting on packages that dangerous driving conditions are forcing delays.

The transportation trouble couldn't come at a worse time: many companies are at the height of their holiday shipping period.

Larger companies have meteorologists on staff who can help route trucks around storms or stop them altogether. Smaller companies have to make do with what's thrown at them, weather-wise.