Portland Monday weather: Low temps threaten icy commute.

UPDATE 3:22 p.m.

ALERT: SW Skyline Blvd from West Burnside to SW Westgate Drive is CLOSED. View all road closures in our Winter Weather Center at https://t.co/6xT5vEJCTR#pdxtraffic #pdxtst #pdxsnow pic.twitter.com/PlnFIQtBXO — Portland Bureau of Transportation (@PBOTinfo) February 18, 2018

UPDATE 3:16 p.m.

UPDATE 3:14 p.m.

UPDATE 3:12 p.m.

UPDATE 3:03 p.m.:

UPDATE 2:21 p.m.:

UPDATE 2:20 p.m.:

Now the snow is sticking ! pic.twitter.com/N74bY5ygXK — Maxine Bernstein (@maxoregonian) February 18, 2018

UPDATE 1:14 p.m.

Snowflakes fluttering at Lithia Park in Ashland. pic.twitter.com/4WHa0dnzAm — Jamie Hale (@HaleJamesB) February 18, 2018

UPDATE 1:13 p.m.:

UPDATE 10:20 a.m.: Multnomah County says it will open warming shelters Sunday night. According to a news release: "Transition Projects will open severe weather shelters tonight at Bud Clark Commons (655 N.W. Hoyt, in Portland), Imago Dei (1302 S.E. Ankeny, in Portland) and Sunrise Center (18901 E. Burnside, in Gresham). Shelters at Bud Clark Commons and Imago Dei will be open to adults, couples, and pets from 8:30 p.m. Sunday, Feb. 18, to 7:30 a.m. Monday, Feb. 19. Sunrise Center will be open to adults, couples, and pets from 9 p.m., Sunday, Feb. 18, to 7:30 a.m. Monday, Feb. 19. 211info will coordinate transport for anyone who needs shelter but does not have a way to get there.

"Portland Homeless Families Solutions has space available for families, by reservation, at their winter shelter site at Congregation Beth Israel. Contact 211 for an intake. Families with children should contact 211 directly to access and arrange transport as needed to severe weather shelter.

"Additional sites may open as conditions change. Several community-led warming sites also are expected to open. Anyone in need, or who knows someone in need, should check ongoing communications about available shelter by visiting 211info.org and signing up for alerts."

UPDATE 9:36 a.m.

UPDATE 9:14 a.m.: Need to check your elevation? Find it here.

UPDATE 8:56 a.m.: The National Weather Service in Portland has a winter weather advisory in place until 6 p.m. Sunday. It warns of rain and snow showers, slippery road conditions in some areas, in snow accumulations of 1-3 inches at elevations above 500 feet. Lower elevations could see slushy accumulations of less than an inch.

Snow fell early Sunday in some hills around the Portland metro area. Forecasters still expect snow showers mixed with rain through the day.

The snow in lower elevations may accumulate to about an inch but one to 4 inches may fall above 500 feet. Colder temperatures then are expected to arrive for Presidents Day in what the National Weather Service is calling the "coldest air mass of the winter."

Some locations may see record lows as the cold lingers into Tuesday. Lows are forecast to be in the mid to low 20s.

It’s snowing - but not sticking here in SW Portland . pic.twitter.com/FGQv0dABLG — Maxine Bernstein (@maxoregonian) February 18, 2018

Downtown Portland cold and wet, but not (yet) snowy. pic.twitter.com/UbQTOd0Tu5 — Mary Mooney (@MaryKnitsPDX) February 18, 2018

Here is the Weather Service's modeling from Saturday: