Early Sunday morning, Jan. 12, 2020, the National Weather Service issued an urgent ‘Winter Storm Watch,’ warning of “heavy snow possible late this afternoon and evening.”
Snow accumulation of 1 or 2 inches is likely and 3 to 5 inches possible.
Prognosticators say that a cold front will move in late this afternoon.
“This band is associated with the cold outflow of the Fraser River Valley, providing cold air for snow when Sunday’s weather system moves through,” Meteorologist Cliff Mass said.
Mass adds:
“More snow occurs as the cold air is forced to rise on the northern slopes of the Olympics. Another region of snow (.5 to 3 inches) is found from Seattle southwards, where the cold northerly flow converges with westerly/southwesterly flow from off the Pacific. So at this point, south Seattle looks more heavily effected.”
Here’s the full Winter Storm Watch:
Winter Storm Watch
URGENT – WINTER WEATHER MESSAGE
National Weather Service Seattle WA
230 AM PST Sun Jan 12 2020
WAZ507-509-511-556-558-559-130000-
/O.CON.KSEW.WS.A.0002.200112T2300Z-200113T1400Z/
Everett and Vicinity-Tacoma Area-Hood Canal Area-
Bellevue and Vicinity-Seattle and Vicinity-Bremerton and Vicinity-
including Everett, Lynnwood, Marysville, Stanwood, Tacoma, Fife,
DuPont, Puyallup, Shelton, Seabeck, Belfair, Brinnon, Bellevue,
Bothell, Kenmore, Mill Creek, Clearview, Kirkland, Newcastle,
Redmond, Sammamish, Issaquah, Seattle, White Center, Tukwila,
Renton, Burien, Des Moines, Kent, Federal Way, Bremerton,
Poulsbo, and Indianola
230 AM PST Sun Jan 12 2020
…WINTER STORM WATCH REMAINS IN EFFECT FROM THIS AFTERNOON
THROUGH LATE TONIGHT…
* WHAT…Heavy snow possible late this afternoon and evening.
Snow accumulation of 1 or 2 inches likely and 3 to 5 inches
possible.
* WHEN…From Sunday afternoon through Sunday night.
* IMPACTS…Travel could be very difficult.
PRECAUTIONARY/PREPAREDNESS ACTIONS…
Monitor the latest forecasts for updates on this situation www.weather.gov/seattle
Here’s the detailed 7-day forecast:
-
- Today: Rain. Temperature falling to around 38 by 5pm. Breezy, with a southwest wind 17 to 23 mph, with gusts as high as 30 mph. Chance of precipitation is 90%. New precipitation amounts of less than a tenth of an inch possible.
- Tonight: Rain and snow, becoming all snow after 11pm. Low around 29. Wind chill values between 22 and 27. South wind 7 to 11 mph becoming north northwest in the evening. Chance of precipitation is 80%. New snow accumulation of 1 to 2 inches possible.
- Monday: A 50 percent chance of snow. Cloudy, with a high near 32. Wind chill values between 20 and 30. East northeast wind 3 to 6 mph. New snow accumulation of less than a half inch possible.
- Monday Night: A 50 percent chance of snow. Cloudy, with a low around 25. North northeast wind around 7 mph. New snow accumulation of less than a half inch possible.
- Tuesday: A 30 percent chance of snow. Mostly cloudy, with a high near 31. East northeast wind around 5 mph becoming light and variable in the afternoon. New snow accumulation of less than a half inch possible.
- Tuesday Night: A 40 percent chance of snow. Mostly cloudy, with a low around 25. New snow accumulation of less than a half inch possible.
- Wednesday: Snow likely, mainly after 11am. Cloudy, with a high near 36. Chance of precipitation is 60%. New snow accumulation of less than one inch possible.
- Wednesday Night: Snow likely. Cloudy, with a low around 28.
- Thursday: Snow likely. Cloudy, with a high near 35.
- Thursday Night: A chance of rain and snow. Mostly cloudy, with a low around 30.
- Friday: Rain and snow likely. Cloudy, with a high near 41.
- Friday Night: Rain likely. Cloudy, with a low around 35.
- Saturday: Rain likely. Cloudy, with a high near 44.
RESOURCES:
-
- National Weather Service: https://www.weather.gov/sew/
- Follow #wawx on Twitter: https://twitter.com/hashtag/wawx?src=hashtag_click
- School closures/delays: https://www.kent.k12.wa.us and https://www.kent.k12.wa.us/Page/10443
- Kent Traffic: https://www.kentwa.gov/services/transportation-and-streets/traffic-advisories
- Puget Sound Energy Outage Map: https://www.pse.com/outage/outage-map
- WSDOT Seattle Area Traffic Cams: https://www.wsdot.com/traffic/seattle/default.aspx
- Follow local weather expert Michael Snyder on Twitter: https://twitter.com/SeattleWXGuy
Quick glance at the Winter Storm Watch (blue shade) and Winter Storm Warning (pink shade) across W WA. We will continue to update the forecast this afternoon, so please stay tuned for the latest information. #wawx pic.twitter.com/ggKiumvgfo
— NWS Seattle (@NWSSeattle) January 12, 2020
#wawx You can see the arctic air mass move out over relatively warm water, start it convective process called “Open Cellular Convection” and move back into western WA. Initial snow will have to come from convection tapping cold air aloft initially. Confident in Low position. pic.twitter.com/bRu84shBAR
— Michael Snyder (@SeattleWXGuy) January 12, 2020
#wawx I’ve seen thundersnow in Seattle area 5 times in my life that I can remember off top of my head. 1981, Dec 1990, March 2002, Jan 2005, Nov 2010. Can’t rule it out tonight and tomorrow morning, however the odds are <20% in my best guess.
— Michael Snyder (@SeattleWXGuy) January 12, 2020