Snow leaves mess in Seattle, sets stage for deep freeze

Snow leaves mess in Seattle, sets stage for deep freeze
SEATTLE - Snow tapered off Thursday evening across much of central Puget Sound after snarling the morning commute in the Seattle metro area with hundreds of spinouts, nightmarish traffic backups and stranded vehicles on many highways and side streets.

The storm left behind a slick, frozen mess of icy roads and highways that continued to bedevil the evening commute and threatened more havoc for Friday morning, as temperatures plunge far below freezing overnight. Snow continued falling Thursday evening in parts of south Puget Sound and Tacoma.

A jackknifed semi-trailer shut down State Route167 in both directions at State Route 410 between mileposts 8 to 10 near Puyallup around 4 p.m. leaving drivers to wait for nearly seven hours in their cars for the road to be cleared and sanded. Traffic began moving again just before 11 p.m. with the southbound lanes reopening and northbound traffic being detoured.

Many school districts throughout the region again closed or delayed classes Thursday due to ice and snow, and a few had already announced schedule changes for Friday as well (see complete list).

Dozens of Metro transit routes were disrupted by the snow and by collisions, leaving many commuters waiting in the subfreezing cold at stops for buses that often never arrived.

The snowstorm was ushered in at about 5 a.m. by booming thunder that echoed eerily across the region and sent flashes of lightning piercing through the early morning darkness.

But as the day wore on, snow showers decreased in intensity and frequency. Only a few flurries remained in most of the central Puget Sound as darkness moved in, and the snow was expected to decrease in the south Sound as well later this evening.

That opened the door for the next act in the wintry drama - a deep freeze that could push overnight temperatures into the upper teens or low 20s.

Areas especially hard hit Thursday included parts of State Route 520 on the Eastside as snow buried the highway and drivers abandoned their vehicles on the roadway. By Thursday evening, transportation officials pleaded with motorists to avoid 520 and Interstate 90 if at all possible.

Seattle-area motorists more accustomed to rainfall did their level best to battle with the snow, but often the snow came out the winner.

One of those who lost the battle was Mary Prince, who got caught in a 12-car pileup near Kirkland Thursday morning.

"We got on the hill, and it was all a bunch of ice," she said. "Everybody started going this direction and started piling up. You don't feel like you're in danger so much - you just feel helpless."

Earlier in the day, Bellevue city officials asked people to stay off of the roads as near white-out conditions brought 3 to 5 inches of snow throughout the city.

Throughout the region, crews worked all day to clear emergency routes and primary arterials routes before the forecasted hard freeze settles in and turns the snow to ice overnight.

State troopers and local law enforcement officers responded to spinouts and crashes all day Thursday as drivers encountered compact snow and ice in areas that saw snowfall Wednesday, and new snow showers were catching many drivers off guard.

On I-405, I-5 and I-90 in King County, traffic was snarled in many areas. DOT officials have plow and de-icer crews out, but the snow was coming down faster than it could be cleared earlier in the day.

Throughout the region, side streets and hills continued to pose a problem for drivers, with a steady stream of collisions being reported. Those who decided to leave their cars at home and take public transportation were only a little better off, as many buses could not reach all roads on the schedule routes, and some were involved in accidents.

Despite the large number of collisions Thursday, there were no serious injuries reported.

In Kitsap County officials said freezing weather may have claimed the life of a man who wandered from his house wearing only light clothing. The sheriff's office said John Clarence Makepa Basso, 36, had been suffering from a medical condition and had observed him behaving erratically recently. He was found dead in a heavily wooded area near his residence Wednesday afternoon.

In addition, a boy was seriously injured in a sledding accident in Kent. Officials said the boy was riding on a sled being towed by a car when the sled went under the back end of a parked vehicle near 226th Street and 127th Avenue.

A WINTER WEATHER ADVISORY will expire at 6 p.m. for the greater Puget Sound area. In the Strait of Juan de Fuca area, the advisory expired at 4 p.m.

For South Sound and Southwestern Washington, the advisory has been extended until midnight, where scattered snow showers will continue until then, putting down 1-3" in individual cells.

Thursday's snow is just part two of a major snowfall that dumped 1-2 feet in parts of Skagit, Island and northern Snohomish County through the day Wednesday. Steady snow fell for most of the day there as the Convergence Zone stalled over the area. A spotter outside of Arlington reported 23" as of late Wednesday afternoon.

Snow Totals So Far

Here are some unofficial snow totals with this storm:

  • Arlington (Outskirts): 23"
  • Darrington: 23"
  • Concrete: 21"
  • Elwha: 20"
  • Sedro-Woolley: 18.5"
  • Mount Vernon: 14.5"
  • Randle: 14"
  • Sultan: 13"
  • Bellingham: 13"
  • Monroe: 12.5
  • Port Angeles Outskirts: 10-15"
  • Hamilton: 12"
  • Redmond (Novelty Hill): 10"
  • Hoodsport: 10"
  • Stanwood: 10"
  • Onalaska: 10"
  • Grand Mound: 9"
  • Oak Harbor: 7"
  • Anacortes: 6.5"
  • Hamilton: 6.2"
  • Kirkland (Rose Hill): 6"
  • Beacon Hill: 6"
  • Olympia: 6"
  • Marysville: 6"
  • Woodinville: 6"
  • Rochester: 6"
  • Granite Falls: 5.5"
  • Clearview: 5.5"
  • Sekiu: 5"
  • Mercer Island: 5"
  • Tumwater: 5"
  • Neah Bay: 5"
  • Chimacum: 5"
  • Orcas Isl: 5"
  • Mukilteo: 3"
  • Ferndale: 4.5"
  • Bainbridge Island: 4"
  • Lynnwood: 4"
  • Port Townsend: 4"
  • Port Orchard: 4"
  • West Seattle: 4"
  • Potlatch: 4"
  • Lacey: 4"
  • Arlington: 4"
  • South Everett: 4"
  • Friday Harbor: 4"
  • Mill Creek: 4"
  • Ravensdale: 4"
  • Bellevue: 3-4"
  • Redmond: 3-4"
  • Ferndale: 3.5"
  • Gig Harbor: 3"
  • Lopez Island: 3"
  • Hoodsport: 3"
  • Freeland: 2.5"
  • Shelton: 2"
  • Kingston: 2"
  • Bothell: 2"
  • Seattle (Seattle Center): 2"
  • Tacoma: 1"
  • Mountlake Terrace: 1"
  • Duvall: 11"
  • Sammamish: 5"
  • Bainbridge: 5-6"
  • North Bend: 7"
  • North Tukwila: 7"
  • Graham: 6.5"
  • Bonney Lake: 5"
  • Parkland: 4"

What's Up With This Convergence Zone?

Convergence Zones are caused by colliding winds -- a north wind from the north and a south wind from the south. When those winds collide, they get forced upward, where the air condenses into clouds and storms form.

Zones historically are responsible for some of the area's greatest snows, and this one was no different. Arlington had a snow report of 23" as of 10 p.m. Wednesday, and all that snow that fell into Skagit and Snohomish County from about noon on has been at the hand of these colliding winds.

The massive snow storm of Dec. 18, 1990, was also born from a Convergence Zone that set up shop over Downtown Seattle, as was the snow and freeze of Nov. 29, 2006 (sort of a mix of a convergence zone and arctic front for that event).

This time, the zone had a stronger southerly component, keeping the zone up north for most of the day Wednesday. Computer forecasting models correctly predicted this zone's formation, leading to forecasts of heavy snow in the Seattle area Wednesday afternoon, but underestimated the storm's southerly wind component, keeping the zone north of the city. It wasn't until Thursday morning that this southerly component weakened, allowing the north wind to gain strength and push the zone south.

Zones form quickly and can shift very quickly, and many times there is not much time to react, as many motirists found Thursday morning. As much as it snarled the Thursday morning commute, imagine if this happened at 1 p.m. Wednesday when everyone would have been in school.

Where Do We Go From Here?

Thursday night will be clearing and cold, with lows in 15-21 range. That means a hard freeze to all that is on the ground today.

Friday should be a lot like earlier this week -- sunny but continued cold -- possibly a few degrees colder than this current spell -- with highs 25-28 and lows Friday night from 10-18.

Saturday also looks dry and continued cold with highs in the mid 20s. But clouds will increase Saturday night, keeping lows around 20.

Those clouds are a signal of our next great forecasting challenge -- a storm heading in for Sunday. This one presents a whole new set of variables, because Mother Nature has a devious sense of humor and a thick playbook, it seems.

This storm is coming in from the west/northwest, and it looks pretty wet. Second, we'll not only have some arctic air here in Western Washington, but even more in Eastern Washington. That air is very dense, and thus has higher pressure.

As the low pressure of the storm approaches, forecasting models are hinting now that we could see some very strong, gusty east winds in the passes to the usual North Bend, Enumclaw, Gold Bar east-windy places -- perhaps as high as 40-50 mph.

That's challenge A. Challenge B -- if so, that would be blowing in a lot of cold air from Eastern Washington into Western Washington -- the "North Bend gets to feel like Bellingham does now for a while" scenario, getting even more cold air into the region ahead of this storm.

So when the storm arrives, in the areas outside the wind, depending on how warm the storm is and how much cold air is around, it'll likely start as heavy snow, then gradually change to rain.

But in areas where that east wind keeps feeding the cold air in, this could present some freezing rain problems along the I-90 corridor. (Portland people can tell us all about this, since they have frequent experience with a similar set up with the east wind blowing out from the Columbia Gorge. In fact, this set up presents them with similar freezing rain problems for their area.)

Bottom line: Sunday could be real messy. It might be lucky for us if the system comes in cooler and it stays as snow because while it'd be quite a bit of snow, ice/freezing rain would be worse. (About all that's left is the blizzard and we'd have collected the entire set of weather problems :) ) Highs will be somewhere between 31-38.

Some lingering snow showers Monday, then we dry out again for the afternoon into Tuesday with partly to mostly sunny skies and highs in the low-mid 30s and lows still in the 20s.

Another not-so-frigid system moves through on Christmas Eve, but at this point, this is looking like the kicker of just snow to rain and highs into the 40s, perhaps ending the cold spell. But a more southerly track, and we could get that White Christmas after all :)