The only difference between adventure and disaster is preparedness.

Friday, November 18, 2011


The following information is the latest from the National Weather Service about the potential for lower elevation snow in Southwest Washington/Portland, OR. As you will note, the forecasters are more confident there will be snow above 1,000' and less confident about a accumulations in the valley but it is best to be prepared.

• SYNOPSIS: A large upper level low pressure system will remain over the Pacific Northwest place through the weekend. This system will usher in a significantly colder air mass with widespread rain and snow showers and quite low snow levels for this time of year. The last disturbance associated with this low will move through southwest Washington and northwest Oregon late tonight and early Saturday.

• PRIMARY AREAS IMPACTED: Coast Range, Cascade Foothills and Cascades. Snow levels 1000 to 1500 feet today, lowering to 500 to 1000 feet later tonight and Saturday morning.


  • Additional snow accumulations of 2 to 5 inches in the Coast Range today and another 2 to 5 inches tonight and early Saturday.

  • Additional snow accumulations of 2 to 4 inches in the Cascade Foothills today and another 2 to 5 inches tonight and early Saturday.

  • Additional snow accumulations of 3 to 7 inches in the Cascades today and another 4 to 8 inches tonight and early Saturday.

  • 1 to 2 inch accumulations are possible later tonight and Saturday morning at the higher elevations around the Willamette Valley and the southwest Washington interior valleys, such as the West Hills near Portland and the hills above Hockinson, Washington. The snow may even mix down to even lower elevations briefly early Saturday with a light dusting as the coldest air is over the area and the disturbance mentioned above moves across the area.

  • Travel may become hazardous with snow covered roads or icy conditions.

  • Hikers, hunters and other outdoor recreation enthusiasts should prepare for winter weather.

• TIMING: Through early Saturday morning (Nov 18-19). Snow potential decreases by Saturday afternoon as moisture becomes limited and the last disturbance moves east.

• FORECAST CONFIDENCE: High confidence in snow in the Coast Range, Foothills and Cascades. Low to moderate confidence in precipitation type for valley locations and the Gorge. Some confidence in accumulations closer to 1000 feet.

• UNCERTAINTIES: Primary uncertainty is snow level. Brief periods of snow or rain mixed with snow may reach near the valley floor in heavier showers.

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