SEATTLE — Halloween could be wet for western Washington trick-or-treaters this year as a system spreads showers across the Puget Sound region Thursday afternoon and evening.
New forecast models are showing the low pressure system off the coast will move away much slower than expected. The result will be some steady rain showers that will move from the southwest to the northeast on Thursday afternoon.
What does that mean for you?
Rain will start mid-afternoon over Olympia and Chehalis and slide up towards Tacoma and Seattle between 5 p.m. and 7 p.m.
By 8 p.m., rain will move up toward Everett and Mount Vernon, with steady rain continuing over Puget Sound and the southwest Interior all the way out to the coast. Bellingham should stay mostly dry until late in the evening, around 10 p.m. or 11 p.m.
Rain will be widespread and steady overnight, with trailing showers expected on Friday.
Cooler air will settle in behind, holding high temperatures down near the 50-degree mark. Snow is expected in the mountains above the 3,500-foot level. Light snow is likely in Stevens Pass with possible flurries but no accumulations at Snoqualmie Pass.
Halloween weather records
Temperatures can fluctuate drastically on Halloween in western Washington, with record high temperatures around freezing to as warm as the mid-70s.
Records at Seattle-Tacoma International Airport
Record warmest (high temp): 71 degrees (1949)
Record coldest (high temp): 41 degrees (1984)
Record coldest (low temp): 30 degrees (2006)
Record warmest (low temp): 54 degrees (1987)
Highest rain total: 1.30 inches (2015)
Records at Olympia Airport
Record warmest (high temp): 74 degrees (1949)
Record coldest (high temp): 42 degrees (1956)
Record coldest (low temp): 14 degrees (2002)
Record warmest (low temp): 53 degrees (2015)
Highest rain total: 2.95 inches (1994)
Records at Bellingham Airport
Record warmest (high temp): 67 degrees (1958)
Record coldest (high temp): 31 degrees (1984)
Record coldest (low temp): 20 degrees (1984)
Record warmest (low temp): 56 degrees (1981)
Highest rain totals: 1.06 inches (1967)