UPDATE | DECEMBER 8TH, 2PM
Well, as predicted, the easterly/south easterly winds started howling around the Snoqualmie Valley Wednesday evening – and pretty much haven’t let up for most of Thursday, with temperatures making it to the low-mid 30’s depending on your Snoqualmie Valley location.
Add in the wind chill and it feels more like the mid 20’s – and if you’ve tried walking anywhere in that howling wind, well, you know just how bitter it is. The North Bend Elementary weather station picked up a 50mph gust Thursday afternoon, with average sustained winds of 22mph.
The Wind Advisory for the Snoqualmie Valley has also now been extended until 10PM tonight. It was originally set to expire at 4PM.
Weather forecasters now say the warm front approaching the Puget Sound area is moving just a tad faster than they anticipated this morning, with snow in Chehalis and approaching Olympia as of 2PM.
According to KOMO Weather producer Scott Sistek, it now looks like there are two bands of snow. The first will have just light snow/flurries in Puget Sound around 3-5PM and the second, or ‘main event,’ comes in around 6-9PM depending on your specific location. The Portland area already picked up 1-2 inches today.
The Snoqualmie Valley is still expected to pick up the low end of the 1-3 inches of predicted snow due to the drying effect of the strong easterly wind. Some weather guys have said it’s not out of the question to see close to no snow for our area unless the east winds slow down.
The warm and cold air will still battle it out tonight, with the dry, cool east wind helping to keep it colder longer, but forecasters still expect that snow to turn to rain before daybreak on Friday.
And yes it can still snow at 35 degrees if the dew point is low enough. As of 2PM the dew point was 11 degrees in Snoqualmie.
UPDATE | DECEMBER 7TH, 3:30PM
And just like that the earlier Winter Storm Watch was downgraded to a Winter Weather Advisory – running from 4PM, Thursday, December 8th through 8AM December 9th. The National Weather Service says 1-3 inches of snow is expected across most Puget Sound lowlands before turning to rain before daybreak on Friday.
A Wind Advisory was also just issued for the Snoqualmie Valley (i.e. Cascade foothill communities) which is in effect from 9PM, Wednesday, December 7th until 4PM December 8th. East winds should 25-35MPH with gusts up to 45MPH, which is often considered a ‘walk-in-the-park’ winter wind event for longtime Valley residents.
NOTE: the predicted east wind may keep snow totals lower in the Valley due to the drying effect of the downslope wind.
UPDATE | DECEMBER 7TH, 1PM
Local weather forecasters now think the snow will arrive later Thursdays evening, moving into Washington from south to north. They also think the snow will be slightly lighter – like 1-3 inches for the Seattle-Bellevue metro areas. They still think foothill communities will get the low end their predictions, as the easterly winds will dry up the snow before it falls – and the low pressure center might stay farther off shore.
** There’s also a chance of freezing rain in the Snoqualmie Valley overnight Thursday when the warm air moves in. **
ORIGINAL STORY
As predicted, cold air has filtered into western Washington. Snoqualmie was at 23 degrees early Wednesday, December 7th. Two days ago, weather forecasters thought an incoming wet weather system would start as snow and then quickly turn to rain, scouring out all the cold air.
Now the weather forecast is trending toward the cold air winning the battle of the atmosphere (at least for awhile), which appears to be setting our area up for a classic Puget Sound snow event – a warm, wet weather system overriding stubborn cold air.
This has resulted in another Winter Storm Watch being issued for our area, which runs from 7AM Thursday December 8th through Friday, December 9th at 7AM.
While it looks like good odds for winter fans to see some snow, UW Atmospheric Science Professor Cliff Mass says the Snoqualmie Valley could see less than other areas.
Why? GAP WINDS
Our notorious easterly winds that get sucked through the nearby Cascade Mountain passes are predicted to start kicking up Wednesday afternoon/evening. As that incoming low pressure weather system starts moving north up the Pacific Coast – the one that will bring [possible] snow – toward Washington, it will suck air from high pressure to the east in a stabilization effort between those low and high pressure systems.
The result is gap winds for communities near the mountain like North Bend and Snoqualmie. Forecasters are predicting breezy conditions starting Wednesday evening/night, with gusts possible in the 40MPH range.
SNOW ARRIVAL
The snow is expected to make it to the Snoqualmie Valley Thursday evening. Earlier forecasts called for Thursday afternoon. BUT again, due to the easterly winds, forecasters think that downslope east wind could dry up some of the snow.
So where as those easterly winds could keep our area cooler longer as cold air from eastern Washington is pulled in, it could also dry up some of that falling snow and leave us with less overall inches.
Per the Winter Storm Watch, snow could fall for 12 hours before the warm air wins out and the snow turns to rain early Friday morning – and four inches or more of snow is possible for most interior lowland locations.
Warning: Snow amounts are dependent on how long it takes for the snow-to-rain transition to occur, and weather forecasting models have varied on this over the past couple of days. That’s why websites like Wunderground show 1-6 inches possible for Snoqualmie.
So be prepared – a little wind and possibly a little, or a lot, of snow – and this story will be updated if the forecast changes yet again.
