Not Pineapple express, that's a large area of warm moist tropical air that usually sends frezzing levels to 7K or above. Snoq. is relatively low elevation, so prone to rain/snow weather mix. Also if winds are out of the east, they will bring cooler air form Eastern WA, thus snow. Westerly winds can bring warmer ocean air. Currently there are a number of weather systems moving though the area, causing freezing levels to bounce around a bit.