I got a call from my mom in Sammamish, WA this evening and she told me that it was snowing hard with several inches of snow on the ground. Sammamish is my hometown and is located 30 minutes east of Seattle near the Cascade foothills and typically receives more snow than Seattle proper. However, snow anywhere in the Western Washington lowlands is not a common event even in the depths of winter, let alone at the end of March! The culprit for the snow is the infamous Puget Sound Convergence Zone (PSCZ), which creates an area of focused precipitation in the central Puget Sound region as winds wrapping around the Olympic Mountains collide. The unseasonably cool airmass combined with the rapid precipitation rates within the PSCZ dropped snow levels down to sea level near Lake Sammamish and resulted in heavy snow this evening. The PSCZ is especially favorable for accumulating snow fast on the plateau of Sammamish which is between 300-600 feet above sea level and tonight was no exception. The precipitation fell largely as rain further west in the larger cities of Bellevue and Seattle.