WES Case Analysis of a Columbia Basin Dust Storm

摘要

This WES case is a Dust Storm event that occurred during the afternoon and early evening on 16 March 2005. This event was chosen because it challenges forecasters to consider warnings and advisories for both high wind and for blowing dust. For the majority of locations in the Columbia Basin observed wind speeds were just slightly below high wind criteria. Accordingly, one challenge this case presents is choosing between the issuance of high wind warnings versus wind advisories. A second challenge is estimating visibilities due to blowing dust. Because fall (not spring) is the peak season for dust storms, some forecasters may tend to underestimate the threat of low visibilities due to blowing dust. In reality, blowing dust was a greater threat than damaging wind, e.g., in at least 4 zones roads were closed due to near zero visibility from blowing dust.