Thunderstorm Wind in Clark County, Washington

An unusually intense storm was able to generate a strong downdraft despite limited environmental support, which resulted in a narrow damage swath in Meadow Glade, WA in Clark County. NWS Portland conducted a damage survey in the affected area on Sunday, June 7. NWS storm surveyors found a small area at the west end of the storm track which experienced heavier damage, including a metal roof peeled back from an outbuilding and multiple hardwood trees with trunks snapped multiple feet above ground level. These damage indicators suggest a maximum wind speed of just over 90 mph. As the storm moved east, associated wind speeds weakened, producing minor damage including small downed or broken tree limbs, lifted roof shingles, and damaged fences, corresponding to wind speeds of 50-65 mph.

An upper-level trough moving through the region combined with cooling temperatures aloft and daytime heating to facilitate shower and thunderstorm activity. A shower was strong enough to produce a cold-air funnel along the coast in addition to a short lived thunderstorm producing strong outflow winds in southwest Washington.