NWCC Briefing Book - SNOTEL Data Collection

SNOTEL Data Collection

NWCC/Table of Contents
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.


Chalk Creek #1 SNOTEL Site, Utah

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.


Map of SNOTEL Sites

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

------------------------------------------------------------------------------- STATE PERCENT OF AVERAGE RIVER BASIN Number Snow Water Accum of Sites Equivalent Precip ------------------------------------------------------------------------------- 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