Water and Climate Program
Products and Services Briefing Book
SNOTEL Data Collection
Even though the data from the snow courses provide a valuable body of
information, the typical schedule for manual surveys results in weeks with
no specific insight into the condition of the snowpack. In that time,
intense storms may be adding an abnormally large amount of snow or rain;
perhaps an unseasonable warm spell at high elevation is resulting in a
rapid melt with ensuing flood hazards.
Snow surveyors and water managers realized early in the development of
the program that timely forecasting and management decisions required more
frequent measurements and additional information. They also needed a way
to survey particularly remote and hazardous snowpacks. SNOTEL's automatic
sensing and data transmission were the solution.
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| Chalk Creek #1 SNOTEL Site, Utah
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A typical SNOTEL remote site consists of measuring devices and sensors,
a shelter house for the radio telemetry equipment, and an antenna that
also supports the solar panels used to keep batteries charged. A standard
sensor configuration includes snow pillows, a storage precipitation gauge,
and a temperature sensor. The snow pillows are envelopes of stainless
steel or synthetic rubber containing an antifreeze solution. As snow
accumulates on the pillows, it exerts pressure on the solution.
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| Map of SNOTEL Sites
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Automatic measuring devices in the shelter house convert the weight of
the snow into an electrical reading of the snow's water equivalent-- that
is, the actual amount of water in a given volume of snow.
The precipitation gauge measures all precipitation in any form that
falls during the year. The temperature sensor determines the minimum,
maximum, and average daily readings.
Additional sensors can be incorporated into a particular site for
measuring wind speed and direction, soil temperature, snow depth, and a
variety of other weather and environmental aspects. The configuration at
each site is tailored to the physical conditions, the climate, and the
specific requirements of the data users.
United States Natural Resources Water and Climate Center
Department of Conservation Portland, Oregon
Agriculture Service
S N O W - P R E C I P I T A T I O N U P D A T E
Based on Mountain Data from NRCS SNOTEL Sites
As of FRIDAY: APRIL 18 , 1997
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STATE PERCENT OF AVERAGE RIVER BASIN Number Snow Water Accum of Sites
Equivalent Precip
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ARIZONA SALT RIVER BASIN ............................. 3 of 8 * 97 VERDE
RIVER BASIN ............................ 2 of 5 * 85 CENTRAL MOGOLLON RIM
......................... 2 of 4 63 85 LITTLE COLORADO - SOUTHERN
HEADWATERS ........ 3 of 5 43 90 SAN FRANCISCO RIVER BASIN
.................... 1 of 3 * 89 GILA RIVER BASIN
............................. 1 of 3 * 91 CALIFORNIA NORTHERN GREAT BASIN
......................... 3 of 4 107 131 TRUCKEE RIVER
................................ 6 of 7 96 150 LAKE TAHOE
................................... 7 of 8 89 155 CARSON RIVER
................................. 3 of 4 101 144 WALKER RIVER
................................. 4 of 5 134 146 KLAMATH
...................................... 9 of 10 111 137 
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