PADD 4-5 (Rockies and West Coast) propane stocks

Unlike the rest of the areas on this site, the Rockies and West Coast are reported as one combined region because EIA does not publish a separate propane stocks figure for PADD 4 or PADD 5. It is also the smallest of the storage regions tracked, without the same interstate pipeline access that links the Gulf Coast to the Midwest and the East Coast, so propane moves more on local gas processing, rail and truck than on a single trunk line. That leaves this region's stocks more exposed to local production swings than the other PADDs. Stocks build from spring through summer and draw down through the heating season on the same calendar as the rest of the country, and the five-year band is the reference for whether this combined region carries its usual cushion into the colder months.

One line covering everything from the Rockies to the Pacific coast, Alaska and Hawaii is a wide area to read from a single figure. A build in Rockies gas-plant storage and a draw on the West Coast can cancel each other out inside it. The count is primary storage, propane and propylene together, in thousand barrels, out each Wednesday in the Weekly Petroleum Status Report for the week ended the prior Friday and revised later against monthly data. The combined volume is small next to the Gulf Coast, so week-to-week percentage swings look dramatic here on moves the national number would barely register.