WESTERN WASHINGTON — Heat and humidity are set to make for a sticky coupling around western Washington on Tuesday. The unusual Northwest combination has earned the attention of the U.S. Storm Prediction Center for May 12.
Surface winds become east-northeasterly on Tuesday as a brief thermal trough reaches up the West Coast. Easterly winds coursing through the gaps in the Cascades will warm the valleys below well into the mid-80s, including North Bend, Maple Valley, and Gold Bar. Seattle and Tacoma should surge into the low 80s on Tuesday afternoon, which is about 15 degrees above average for mid-May.
At the same time, and approaching system over the Pacific will inject increasing moisture into the skies above us, bringing on a relatively muggy and sticky feel. We’ll notice the skies change from bright and blue to noticeably filtered sunshine due to high cloudiness late in the day as the disturbance moves closer. The combination of unusual warmth and humidity will qualify as a short-lived heatwave for Puget Sound…