A wet weather pattern is exptected to bring steady rainfall to Mercer Island and the rest of the Puget Sound region this week.
The forecast has prompted the National Weather Service to issue a flood watch for several areas, including Mercer Island. The local forecast calls for rain the rest of the week, with high temperatures reaching the upper-50s Wednesday through Friday.
Often referred to as a "Pineapple Express," this type of local weather pattern originates in Hawaii and brings uncommonly warm temperatures—along with plenty of rainfall.
In the Olympics and North Cascades, the warm air will cause freezing levels to rise to 6,000 feet and bring 4 to 7 inches of rain. Lighter rainfall is expected through at least Wednesday in the Puget Sound lowlands and other parts of the Cascades.
"For the middle of March, this will be a notable event, worthy of a proper name," UW professor Cliff Mass writes on his weather blog, after dubbing the storm "Poseidon."
