2013年1月4日星期五

Despite getting some big storms last month

Extraordinary snowfall needed to relieve drought
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    In this Dec. 28, 2012 photo, Bales…

    ST. LOUIS (AP) — When his drought-stricken Nebraska farm was blanketed with several inches of snow, Tom Schwarz welcomed the moisture. But it wasn't nearly enough.

    He had hoped for a wet, snowy winter. Instead, he's watched with worry as the sky spits mostly flakes that don't stick.

    "I just shudder to think what it's going to be if we don't get snow," Schwarz said. "A friend told me it would take 150 inches of snow to get us back to normal precipitation."

    Despite getting some big storms last month, much of the U.S. is still desperate for relief from the nation's longest dry spell in decades. And experts say it will take an absurd amount of snow to ease the woes of farmers and ranchers.

    The same fears haunt firefighters, water utilities and many communities across the country.

    Winter storms have dropped more than 15 inches of snow on parts of the Midwest and East in recent weeks. Climatologists say it would take at least 8 feet of snow — and likely far more — to return the soil to its pre-drought condition in time for spring planting. A foot of snow is roughly equal to an inch of water, depending on density.

    Many areas are begging for moisture after a summer that caused water levels to fall to near-record lows on lakes Michigan and Huron. The Mississippi River has declined so much that barge traffic south of St. Louis could soon come to a halt. Out West, firefighters worry that a lack of snow will leave forests and fields like tinder come spring, risking a repeat of the wildfires that burned some 9.2 million acres in 2012.

    Scores of cities that have already enacted water restrictions are thinking about what they will do in 2013 if heavy snows and spring rains don't materialize.

    For a while, it seemed no snow would come. Midwestern cities including Chicago, Milwaukee and Des Moines, Iowa, had their latest first snows on record. How much would it take to make things right?

    "An amount nobody would wish on their worst enemy," said David Pearson, a National Weather Service hydrologist in Omaha, Neb. "It's so out of this world it wouldn't make much scientific sense (to guess). It would take a record-breaking snowfall for the season to get us back on track."

    That's why Schwarz is worried about his 750 acres near Lexington in south-central Nebraska. To save his corn last summer, he pulled water from deep wells and other sources in his irrigation district, but the alfalfa he couldn't irrigate died, something he's never had happen before.

    The soil was so dry he didn't even try to sow winter wheat, a crop that's planted in the fall and goes dormant over winter, relying on snow as a protective blanket.

    "If we don't get snow, we'd better get rain this spring or we're done," Schwarz said.

    The 150 inches — more than 12 feet — isn't likely to materialize. That would be about four times the average winter snowfall in Chicago, a city famous for its storms. Schwarz's area usually gets about 29.5 inches of snow during the winter. As of Dec. 27, it had just 6.5 inches.

    Even if a massive storm developed, the temperature would have to be right for farmers to benefit. If snow melts on frozen ground, the water will run off into rivers and streams, instead of being absorbed into the soil.

    Runoff would be welcome in Sioux Falls, S.D., which was among countless communities that clamped down on water use last summer as rivers and lakes that supply power plants and households grew shallower.

    South Dakota's biggest city imposed its first water restrictions since 2003 as the Big Sioux River, which recharges its aquifers, dropped. Homeowners were limited to watering lawns once a week. Washing outdoor surfaces like sidewalks, driveways and parking lots was banned.

    "This is the driest year in our town's history since the early 1950s," Mayor Mike Huether said as 2012 drew to a close.

    With just 5 inches of snow and some rain so far this winter, the conservation efforts will be back in place for 2013 "unless we get one heck of a snowfall and bust this drought," Huether said.

    Western states rely on snow and ice that accumulate in the mountains during the winter for as much as 80 percent of their freshwater for the year, according to the Department of Agriculture's Natural Resources Conservation Service. The melting snowpack replenishes streams, rivers and reservoirs and provides water for cities and crops.

    A deep snowpack can also make the wildfire season more manageable by wetting forests and fields.

    Tom O'Connor, the rural fire chief in Divide, Colo., would relish that after enduring what the governor called the state's worst wildfire season ever in 2012.

    O'Connor's volunteer department responded to more than 80 calls in June, compared with the usual 30 calls. Three-fourths of the calls were related to wildfires.

    The fires came after Colorado got one of its smallest snowpacks in years — by some accounts tying 2002 as the lowest snow buildup in the 45 years that records have been kept.

    Still, climatologists caution that it's too early in the winter to give up hope.

    "We could be singing a different tune this winter if a storm system cooperates," said Dave Robinson, a Rutgers University geography professor who's also the New Jersey state climatologist. "Sometimes you get what you wish for."

    ___

    Associated Press writers Scott Bauer in Madison, Wis.; Matt Volz in Helena, Mont.; and Mead Gruver, Cheyenne, Wyo., contributed to this report.

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