COLUMBIA RIVER GORGE
East winds and icing potential is the meteorologist’s cross to bear – always a tricky part of winter forecasting in Oregon and Washington. Cold wind paired with incoming moisture is a recipe for a snow or icing event for the metro.
The Gorge, some would say, is one of the most gorgeous passageways in the Pacific Northwest, as its mighty terrain features separate Oregon and Washington with the Columbia River. Travel 40 miles from west or east and you will find two completely different climates. This sliver of the PNW can turn paradise into a nightmare for travelers along I-84 in the winter.
The following information is from the National Weather Service Climate Prediction Center
The following information is a collection of 10 weak El Nino winter events, as determined by the Oceanic Nino Index standard. The information is a collection of weather variables (precipitation, snow, temperature) from two locations in the Columbia River Gorge during those 10 weak El Nino winter events.
Weak El Nino Years:
1952-1953
1953-1954
1958-1959
1969-1970
1976-1977
1977-1978
1979-1980
2004-2005
2006-2007
2014-2015
We examined historical data as far back as 1952 from two sides at opposite ends of the gorge. Bonneville Dam (Latitude = 45.6454 Longitude = -121.9523, elevation 62 feet, Multnomah County), and The Dalles (Latitude = 45.6069, Longitude = -121.2047, 150 feet, Wasco County).
Weak El Nino Results Location 1:
The Bonneville Dam on average will see around 33.68” of total precipitation. With a maximum of 56.52” in the 1952-1953 event, and a minimum of 12.30” recorded in the 1976-1977 event.
On average, around 16.38” of total snowfall. With an astonishing maximum of 67.3” from 1979-1980 and a minimum of 0.0” in 2006-2007.
The mean high temperature is 45.53 degrees, with a mean minimum temperature of 35.52 degrees.
One extra note, the 1979-1980 event was the coldest mean high temperature of 42.4 degrees and average minimum temperature of 33.5 degrees. As a result, this happened to be the same year that the massive snowfall total occurred.
Weak El Nino Results Location 2:
The Dalles mean total precipitation during the 10 events came out to 6.91”. With a maximum of 11.06” in 1977-1978 and a minimum of 1.51” in 1976-1977 event. With a mean total snowfall of 8.76”. With a maximum of 45.9” in the event of 1953-1954 and a minimum of 1.5” in 2006-2007. A mean maximum temperature of 46.1 degrees and a mean minimum of 31.9 degrees.
Conclusion:
Bonneville Dam vs The Dalles
Average Total Precipitation – 33.68” 6.91”
Average Snowfall – 16.38” 8.76”
Average High – 42.4 46.1
Average Minimum – 33.5 31.9
As expected, it is on average, more wet for those on the western edge of the Gorge than compared to those on the eastern side. With nearly double the amount of snow. High temperatures are slightly cooler, with a slightly warmer minimum temperature.
Additional Notes:
The last three weak El Nino events (2004-2005 / 2006-2007 / 2014-2015) brought lackluster snowfall totals to Bonneville Dam. With 2.3”, 0.0”, and 1.0” in respect to the year order above. Although it appears the pattern is trending that direction, there have been seven other weak El Nino years that produced over 5″ inches of snow with the outlier of 67.3” in 1979-1980. That being said, both 2006-2007 and 2014-2015 collected over 30” of total precipitation, leading to a mainly rainy winter event for the Gorge. February of 2014-2015 also brought an ice storm to the Western Gorge.