Summary of Western US SNOTEL Snowpack Comparison Update Report
Based on Mountain Data from NRCS SNOTEL Sites
**Provisional data, subject to revision**
Data based on the first reading of the day (typically 00:00) for Thursday, April 18, 2019
State/River Basin Snow Water Equivalent # of Sites Current as Percent of 2018 # of Sites Current as Percent of Median # of Sites 2018 as Percent of Median Alaska 30/59 79    28/59 66    28/59 80    Arizona 23/23 *   21/23 286*   21/23 0*   California 32/32 275    32/32 211    32/32 77    Colorado 104/105 197    101/105 138    101/105 70    Idaho North of Salmon River 31/31 70    31/31 97    31/31 139    Idaho South of Salmon River 63/65 126    64/65 131    64/65 104    Montana 88/91 70    87/91 103    86/91 150    Nevada 29/32 320    29/32 212    29/32 66    New Mexico 21/21 3054    21/21 202*   21/21 7*   Oregon 81/81 153    78/81 131    78/81 84    Utah 90/90 304    89/90 173    89/90 57    Washington 72/76 63    69/76 75    67/76 118    Wyoming 85/85 89    82/85 108    82/85 120    Arkansas River Basin 6/6 345    6/6 145    6/6 42    Colorado River Basin 107/108 193    105/108 143    105/108 74    Columbia River Basin 259/266 86    261/266 101    260/266 118    Missouri River Basin 46/48 79    45/48 108    44/48 140    Rio Grande River Basin 29/29 702    28/29 167    28/29 24    The Great Basin 103/105 280    103/105 188    102/105 67

-M  = Missing data.
 *  = Analysis may not provide a valid measure of conditions.
N/A = Not available.

Footnotes for median and average:
(##) = If less than 30 years are available, this value specifies the number of years used for the median and average calculations.
Sites with less than 10 years available do not have medians or averages.

The SNOW WATER EQUIVALENT represents the depth of water in the snowpack, if the
snowpack were melted, expressed in inches.


Contact your state water supply staff for assistance.

Medians and averages are calculated for the period 1991-2020.

Provisional data, subject to revision.

* Site -- Either: (a) the current value is missing; (b) the median or average for the day is not available or is zero; or (c) for snow water equivalent, the median or average for the day is less than 10% of the maximum median or average value for the year.

* Basin - More than half of the stations for a basin with normals report missing or invalid data.

The basin index is calculated as the sum of the valid current values divided by the sum of the corresponding medians or averages and the resulting fraction multiplied by 100.