Snowpack slips to
normal
Forecast is for
change in weather
By GREG
STAHL
Express Staff Writer
After a
booming, above average start to this winter’s snowfall totals, Mother
Nature slacked off, and snowpack levels are quickly slipping back to
normal, or even below normal, numbers.
The
heavy icing of snow Idaho received in December got the winter off to a
great start, but water experts caution that much more is needed to fill
the state’s reservoirs and lakes. Express Photo: Willy Cook
Winter
snows checked in at close to 150 percent of average in the Big and Little
Wood river basins at the end of December, but following a dry early
January the snowpack had dropped to 94 percent of average by Tuesday.
In fact,
only six of the 16 river basins the Idaho Department of Water Resources
tracks showed numbers above 100 percent, and they are predominately in
southern or western parts of the state.
Snowpacks
levels across Idaho range from 80 percent of average in the upper Snake
River Basin to 140 percent in the desert basins south of the Snake. But
that is only one-third to two-thirds of the average April 1 depth, which
is the traditional date for determining the peak snowfall from the winter.
In fact,
weather patterns of late are remarkably similar to last winter’s, in
which near record low snowpacks kicked off a summer-long drought.
Snowfall
was lacking last winter because a high-pressure system settled over the
Intermountain West and routed storms away. Idaho’s current high-pressure
ridge may be breaking up, however, and more wet weather may be ahead.
The
National Weather Service is predicting a normal winter, although an El
Nino pattern may be forming, which could bring cooler temperatures and
more moisture for the long-term in much of Idaho.
As Sun
Valley Co. and area businesses are quick to point out, December’s
abundant snowfall was good for holiday recreation and business, but a lot
more is needed to refill Idaho's reservoirs and spin its hydroelectric
turbines.
Favorable
weather through the rest of the winter may fill the bill, the multi-agency
Idaho Water Supply Committee said Friday.
"I
guess the message is so far, so good,'' Idaho Department of Water
Resources spokesman Dick Larson said. "We're in better shape than
last year, but we're too early for a conclusion.''
But so far,
the highest snowpacks are in the lower elevations, a few 150 percent of
average locations in Bruneau and Owyhee country. Water experts prefer snow
higher in the mountains so it does not immediately melt in the spring.
The drought
the state endured last summer sucked the moisture from the soil across
southern Idaho, and much of the spring freshet will be absorbed.
This year
resembles 1989 and 1993, which followed droughts and replenished the
reservoir system. But water storage remains low. By Dec. 31, the desert
reservoirs of southern Idaho were nearly empty, with Salmon Falls
Reservoir holding only 5 percent of capacity.
Magic
Reservoir is 7 percent of its capacity, 17 percent of average and 36
percent of last year’s mark for this time in the winter.
"We’re
going to have to have at least normal precipitation from this point on
through the end of the season even to get close (to filling Magic),"
Big Wood Canal Co. Manager Lynn Harmon said.
Harmon,
stressing that it is early to try and predict, said "It’s pretty up
in the air to say what we’re going to be looking at on our
reservoirs."
Priest
River, Dworshak, Lucky Peak on the Boise River and Brownlee Reservoir on
the Snake River reported average storage going into the new year. The
eight major reservoirs in the upper Snake are one-third to one-half of
normal.
The Payette
system is 44 percent full, 70 percent of average; the Boise chain of dams
is 34 percent full, 62 percent of normal.
The
combined storage for 21 Idaho reservoirs and lakes on Jan. 1 was the
third-lowest since 1958. U.S. Bureau of Reclamation officials said that
with a normal winter, the Boise and Payette systems should fill, but the
upper Snake may slightly miss the mark.
"We
live in an area with a high variability,'' said Hal Anderson, Water
Resources administrator. "One pesky high-pressure ridge can
completely change things.''
The
Associated Press contributed to this story.