BOISE, Idaho As skiers in Idaho's central Rocky Mountains welcomed heavy snowfalls Wednesday, the state's southern reaches remained dryer than normal so parched, in fact, that some hydrologists think those areas could end the winter with a water deficit even if the rest of the season brings normal levels of precipitation.
The Bear River Basin in southeastern Idaho has gotten just 63 percent of average precipitation since October, according to snow measurement stations overseen by the federal Natural Resources Conservation Service. So far, none of the river basins in the southern part of the state along the Nevada and Utah borders has had more than 86 percent of average precipitation.
That contrasts with measurements taken in northern and central Idaho. The Panhandle has received average precipitation, the Weiser River Basin has gotten 117 percent of average and precipitation in the mountains above the Henry's Fork of the Snake River measures 111 percent of average.
Water experts have forecast much of Idaho and the Pacific Northwest will have wetter weather and colder temperatures as the "La Nina" pattern in the equatorial Pacific Ocean sends storms this way. So far, however, the state's southern mountains have been left high and dry, getting much the same weather as neighboring Utah where federal NRCS officials report all 13 of the river basins well behind averages.
"It'd be nice to see the southern part of the state get some storms to move through," said Phil Morrisey, an NRCS hydrologist in Boise. "There's a lot of agriculture between here and Twin Falls. Their snowpack is lagging behind."
The economic results are tangible.
Bogus Basin Mountain Resort north of Boise plans to open many of its runs Thursday and some ski areas, including Brundage Mountain in McCall, Sun Valley in Ketchum and Schweitzer Mountain in Sandpoint, have been running for several weeks. But the Pebble Creek Ski Area in Inkom south of Pocatello won't fire up its lifts until after Christmas.
That's critical, because vacationing students can account for a significant share of annual revenue.
"We're not putting a date on it," said Pebble Creek general manager Mary Reichman. "We'll open when we have enough snow."
Federal officials say another key figure to watch is just how much water can be measured in the existing snowpack. Right now, not a single one of Idaho's 19 river basins from Canada to Utah has reached average levels. October and November were relatively warm, so most of the moisture that fell then did so as rain, not snow, and seeped into soil still parched by the heat of a record-hot summer.
The lowest snowpack, or "snow-water equivalent," measurement is in the Owyhee Basin in southwestern Idaho, with just 26 percent of average. The Willow Creek, Portneuf and Blackfoot river basins aren't much better off, at 34 percent. Just one basin statewide, above the Salmon River, is at 90 percent of average snowpack.
Morrisey said it's still early in the season, so a few big storms in coming days, along with normal snowfall for the rest of winter, could change those figures quickly.
There are heavy snow and winter storm warnings for much of northern and central portions of Idaho through the weekend.
Come spring, farmers, Idaho Power Co. and others who depend on a steady water supply want to take advantage of runoff from snow that remains in the high mountains well into summer, to water fields, grow farm-raised rainbow trout, and power turbines in hydroelectric dams.
"We feel there is a deficit that is lurking," Morrisey said. "Until we get two really wet back-to-back years, I wouldn't count the drought out of it at all."
In Idaho, the last eight years have been characterized by drought, with the pattern last interrupted by above-average precipitation in the 2005-2006 winter.