Winter makes a grand return

Winter makes a grand return
SEATTLE -- After several weeks of calm weather, Mother Nature reminded us Thursday morning that Winter is not over. Drivers in the metro area are battling snowy, icy roads, and several schools have closed or delayed classes.

State troopers and local law enforcement agencies were responding to dozens of spinouts and wrecks, and the snow forced several school districts to close or delay classes (see full school list).

Trooper Christina Martin said many area highways were icy, and DOT sanding trucks have been out since 2:30 a.m.

King County Metro said road conditions are also making it difficult for buses, so be prepared for delays or missed stops. You can find detailed route updates on Metro's web site.

In Seattle, city Department of Transportation spokeswoman Mary Beth Turner said crews were sanding city roads and plows and sand trucks were concentrating on major arterial roads, with crews also dedicated to the West Seattle Bridge and Alaskan Way Viaduct.

She said salt was used on the viaduct and bridge, but the conditions weren't severe enough to require salt in other areas.

Where it did snow, most metro area snow totals were running about 1-2" at most, but the far northern areas received several more inches, with Whatcom County and some of the Olympic Peninsula foothills south of Sequim and Port Angeles reporting between 7-11 inches. Some spots of the Cascade foothills also had higher amounts.

However, in a tribute to how variable snow is around the Northwest, many places still had bare lawns Thursday morning.

The main snows are done, aside from a few straggling showers in southwestern Washington and the Cascades. All areas will be dry by this afternoon under partly sunny skies and temperatures will gradually warm into the low 40s.

Our next weather challenge comes tonight, which will see clearing skies and with cold air lingering in place, the entire region will likely drop below freezing. Lows will range from the low-mid 20s in the outlying areas to the upper 20s in the metro areas. That means a hard freeze and icy roads a high concern again for Friday morning, especially where any snow lingers through the day.

What Happened?

Every snow event has a monkey wrench, and this one is the Fraser Valley. The area of low pressure moved through overnight and early Thursday morning as expected, bringing some moisture and snow. Meanwhile, arctic air continued to pool in the interior of British Columbia.

However, the track of the storm drifted a bit to the west and southwest off the coast a little more before it turned inland, and that lower pressure to our southwest pulled more arctic air out of the Fraser River Valley and into Western Washington, dropping temperatures well below freezing and priming, really most of the area for snow, although spots near sea level were still on the edge of freezing.

Meanwhile, a persistent band of showers continued to drop snow in Western Whatcom County for several hours Wednesday evening through Thursday, and snow totals around Ferndale and Lynden were pushing over 8".

As that arctic air drew out of the Fraser Valley, that northeast wind pushed across the northern inland waters and then into Olympic Mountains on the northeastern side of the Olympic Peninsula. As that air lifted up into the mountains, it squeezed out its moisture, and that's why we're seeing such high snow totals in the foothills south of Port Angeles and Sequim.

Down in the metro areas, it was hit-and-miss showers roaming around that area of low pressure. However, as that arctic air did a better job of moving into the region, temperatures dropped into the upper 20s making what normally would just be a slushy 1-2" into an icy 1-2."

Where Do We Go From Here?

As the low continues to move off into Eastern Washington later Thursday morning, it will do two things. First, it will bring an end to the showers and even allow the sunshine to peek out. Second, the wind will shift from blowing that arctic air in from the north, to blowing in warmer, ocean air from the southwest.

That will rapidly push temperatures well above freezing by midday or early afternoon and afternoon high temperatures will climb into the 40s.

We dry out Thursday night, but temperatures will plummet below freezing, making for a potentially icy commute again Friday morning.

By Friday, we're all dry and a bit warmer, climbing up the temperature ladder and heading back over 50 by the weekend.