Tag Archives: snow

BIPOC, Editorial, Health and Lifestyle, Local, National, Weather

Malcontentment Happy Hour: December 21, 2020

Video

Our live webcast from the Seattle Anarchist Jurisdiction

The show from December 17, 2020, featured guest host, Jennifer Smith.

  • Record high, record rain, and snow?
  • Uneven enforcement of Cal Anderson Park closure results in 7 arrests with one injury at Cal Anderson Park
  • Two new strains of COVID-19 in U.K. and South Africa, U.S. holds off on a travel ban, and vaccination delays
  • Seattle Police Department destroys Mutual Aid supplies including food, clothing, and bedding during Cal Anderson Park homeless sweep
  • A $900B stimulus deal is signed by the House and Senate and goes to Trump’s desk
  • The name of the team Atlanta Braves becomes a political issue
  • “Behind the Pole,” Cal Anderson Park homeless sweep
Breaking News, Local, Weather

Intense cold front could bring burst of lowland snow

UPDATED – official high at KSEA was 59 degrees.

[KIRKLAND] (Malcontent News) – After setting an official record high of 59 degrees on December 21, an intense cold front could bring a brief but intense burst of snow into the Puget Sound Lowlands. The National Weather Service has issued a Flood Advisory for a storm system dumping one to two inches of rain through the afternoon into the lowlands. Areas of poor drainage and clogged storm drains could create pockets of urban stream and street-level flooding.  

At 3:00 PM, it was 55 degrees with heavy rain at Seatac Airport, while less than 100 miles to the north, it was 34 degrees with heavy snow in Bellingham. A cold front moving from the north will bring dramatically colder air, and a Converge Zone is expected to form in the next couple of hours. Forecast models indicate that temperatures could drop 20 degrees in two to three hours.

The challenge of forecasting a Convergence Zone is determining its exact location. Colliding winds moving north and south through Puget Sound are left with nowhere else to go but up, creating bands of intense precipitation that can be just 10 miles wide. Areas in these zones can see heavy rain or snow, with calm conditions a few miles away. Typically these zones appear on the King-Snohomish County line. Original forecast models had the zone forming north of Everett today, but current models and weather radar indicate it could develop much further south. 

Areas that get heavy snow could see 1 to 3 inches of accumulation, which will likely melt quickly because surface temperatures are too warm. The intense snowfall could create short term travel problems with reduced visibility and slippery spots on less-traveled roads. Today’s weather system is very similar to storms that moved through the area on November 13, 2003, and November 27, 2006. The November 27 system crippled the Seattle area, turning highways and roads into parking lots filled with abandoned cars. 

Local, Terra Firma, Weather

Significant weather event likely on Friday the 13th

The remnants of Tropical Storm Atsani is charging across the Pacific Ocean, on a collision course with the Pacific Northwest. Although Atsani lost all tropical characteristics days ago, the energy and moisture it collected are expected to arrive Friday in a two-day weather event.

The challenge in forecasting wind storms in western Washington is that the center of circulation’s location determines our region’s impact. If the storm passes to our north, close to the southern tip of Vancouver Island in British Columbia, we get the brunt of a wind event. If the storm passes to our south, up the Columbia River basin, Oregon receives the brunt of the wind. An error in the forecasted path of just 50 miles is the difference between a significant wind event and what we like to call “a nothing burger.”

Typically the computer models aren’t in agreement on the “where,” which is the case with the Friday forecast. The GFS model, which hasn’t been the most accurate for our winter weather, forecasts a significant, possibly historic wind event, with the storm passing over Vancouver Island. The Euro model, which was stellar a few years ago but has lost some accuracy, predicts Oregon will receive the most impact.

It is too far out with landfall still 72 hours away to narrow down the track, but here is what we do know. Forecast models put central pressure at landfall between 973 and 983 millibars – that is significantly more intense than Tropical Storm Eta when it crossed the Florida Keys. Barometric pressure this low is typically associated with Category I and Category II hurricanes (our November wind storms have nothing related to the mechanics of a tropical system, even if they are often the remnants of tropical systems).

Wave height forecasts for Friday and Saturday are, in a word, alarming. Some computer models forecast heights of 45 feet off the Oregon coast, with some models predicting higher than 50 feet.

What should you know? For central Puget Sound, there is growing potential for a significant weather event on Friday and Saturday. More specifically to the eastside, the chances for power loss, tree, and property damage is increasing and require a close watch. Along the coast, damaging waves that will cause low area flooding, erosion, and large debris to wash ashore and shift are likely, with the where being the bigger question. The Cascades can expect wind and mountain snow, and a lot of it. The storm track will determine the snow level, but anyone planning to cross the passes this weekend should consider leaving a day early.

Opening the new SH-520 bridge to relieve wind and wave stress is no longer required, and the latest design also prevents waves from over-topping the railings. Also, with reduced traffic in general due to COVID-19, regional travel shouldn’t be too challenging during the evening commute.

The weather model we prefer? That model shows the storm passing to our north but at the lower end of the strength forecast. We will continue to update this growing situation.

Local, Weather

Skiers rejoice – snow is coming to the Cascades

A cold and wet weather pattern has moved into western Washington, bringing lowland rains and mountain snows. Monday night will see snow levels drop to 2000 feet, enough for the white stuff to fall at all the passes (and our ski areas) through Wednesday morning. All of the passes and ski areas can expect six inches of snow to accumulate. On Wednesday, there is a break before the snow machine turns on again, with snow levels rising to around 3,000 feet. That’s right on the line for a rain/snow mix at Snoqualmie.

For the lowlands, Monday night and Tuesday are looking wet, with a break on Wednesday, followed by two more wet days at the end of the week. Friday is looking windy, but it is still too far out to say if we will see Wind Advisories in the lowlands.

Studded tires became legal again on Washington roads on November 1 this year, and if you plan to cross the passes, you should have a survival kit and tire chains packed. We will continue to monitor the situation.