Snowpack Evaluation

This is the February 1, 2005Washington and Oregon snowpack update, along with comparisons to 2001, 2002,2003 and 2004. The snowpackaverage for the date significantly dropped the latter half of January due to unseasonably mild and dry weather. The Oregon statewide average snowpack average fell to 51% of normal for the date. It ranges from 88% of average in LakeCounty (south-central Oregon) to only 19% of average on the Lower Columbiadrainage (includes the Hood area). Every Oregon river basin is below normal and nine of the twelve major basins are lower than the 2001 drought year.TheWashington snowpack also experienced a significant drop in average. Statewide it is only 33% of normal and ranges from 62% of average on the Columbia River drainage above Methow to a meager 12% on the Cedar/Snoqualmie basin alongthe westside of the Cascades. Most basins are in the 20-30% range. This is much lower than the 2001 drought year and is the lowest snowpack since 1994. With only two months left to accumulate snow, it is likely that this year’s snowpack will remain one of the lowest on record.

I’ve also added a graphic of the low elevation water year precipitation, which includes the total moisture received between Oct 1, 2004 and Jan. 30, 2005. Portions of southern and eastern Oregon, and northwestern Washington continue to show above average amounts of low elevation moisture. However, this too has diminished over the past two weeks as storms have passed either to the north or south of the area.

We will continue to monitor the snowpack through the remainder of the winter and early spring. The next snowpack comparison report will be issued February 14, 2005.

Oregon and Washington Snowpack Comparison
as of February 1, 2005
Oregon
(Percent of Normal)
River Basin / Date / 2005 / 2004 / 2003 / 2002 / 2001
Owyhee / February 1 / 71 / 128 / 65 / 123 / 83
Malheur / February 1 / 57 / 124 / 59 / 122 / 75
Grande Ronde / February 1 / 47 / 115 / 61 / 114 / 69
Umatilla / February 1 / 28 / 113 / 42 / 113 / 61
John Day / February 1 / 57 / 117 / 52 / 104 / 62
Deschutes / February 1 / 54 / 124 / 55 / 133 / 64
Lower Columbia / February 1 / 19 / 137 / 21 / 182 / 67
Willamette / February 1 / 30 / 126 / 32 / 160 / 68
Rogue/Umpqua / February 1 / 51 / 131 / 65 / 126 / 50
Klamath / February 1 / 47 / 125 / 58 / 119 / 50
LakeCounty / February 1 / 88 / 122 / 62 / 112 / 60
Harney / February 1 / 62 / 120 / 45 / 118 / 59
State AVG / 51 / 124 / 51 / 127 / 64

Note:Redfigures indicate lowest snowpack average in past 5 years.

Washington
(Percent of Normal)
River Basin / Date / 2005 / 2004 / 2003 / 2002 / 2001
Spokane / February 1 / 51 / 107 / 65 / 117 / 46
Columbia/Methow / February 1 / 62 / 86 / 90 / 106 / 53
Chelan/Wenatchee / February 1 / 32 / 85 / 79 / 108 / 53
Upper Yakima / February 1 / 20 / 97 / 63 / 112 / 56
Lower Yakima / February 1 / 25 / 111 / 79 / 120 / 44
Walla Walla / February 1 / 26 / 117 / 51 / 121 / 69
Lewis/Cowlitz / February 1 / 26 / 111 / 47 / 140 / 63
White/Green / February 1 / 28 / 104 / 60 / 120 / 46
Cedar/Snoqualmie / February 1 / 12 / 106 / 36 / 129 / 65
Baker/Skagit / February 1 / 30 / 94 / 66 / 115 / 45
Olympic / February 1 / 53 / 91 / 89 / 113 / 83
State AVG / 33 / 101 / 66 / 118 / 57

Paul Werth

Fire Weather Meteorologist (ret)

360.666.8882