Thursday, December 8, 2016

Thursday Snow Nowcast at 3 PM: Snow Moving in Faster Than Expected

Well, our models may have had the right idea of the threat of snow, but the recent runs clearly have a serious timing error.    The snow will arrive 4-5 hours earlier than expected.

The latest radar image  (2:27 PM) shows the story--the precipitation shield from the warm front has reached the south Sound.  Once precipitation starts aloft, it takes about an hour to reach the surface (need to humidify the layer below)


The latest visible satellite image shows an impressive cloud band with the warm front.

Let me show you some traffic cams.

It has been snowing in Portland for hours.

Vancouver
 Longview

Here is the Chehalis Airport

  Centralia.
Dupont, north of Olympia at 3:30


It should starting snowing at the surface in Olympia by 3PM.  At the current rate of progress, the snow will get to Tacoma around 4 PM and Seattle by 5-5:30 PM.

There appears to be multiple bands...the first band is producing the above snow.  It appears to be weakening over southern Puget Sound...and slowed down.  So it looks like Seattle commute will be ok.   The second band, which should arrive later (if the models are right), well be more of a threat for Seattle and points north...later in the evening.

80 comments:

Unknown said...

Are the models for snow depth the same or similar to those of yesterday?

MBeebe said...

Cliff,

Does this early arrival change the amount of snow Seattle should expect?

Unknown said...

Thanks for the update! I will definitely be leaving work early. Are we still expecting a light snowfall in Seattle?

Reader said...

Started snowing here in Olympia at 2:57 pm--State St and Turner.

Bryan Black said...

Take a look at the 16-day GFS. Never seen anything like it since I moved to Oregon in 1989.

Gpacharlie said...

Cliff,
Baased on the models yes but ,mostly on your on-going analysis of them, I predict the first snowflake at my house to occur in exactly 16 minutes and 30 seconds based on the radar info and your meteorological information regarding precipitation calculated for our elevation and windspeed history over the last 45 minutes. I will go out on a limb and predict 2.3" of total snow accumulatiom by 4:20 am tomorrow. I will
Et you know how it turned out. Thanks professor.

Gpacharlie said...

OOPS. I did not factor in the accelerated downsloping winds occuring at dusk which have effectively scoured a big blue hole in my precipitation forecast. Forecasting is really tough.

Anisa Redmond said...

And Cliff, how about north of Seattle? Or does the buck stop there?

Feeling left out of the snow. I was expecting 3-5 inches.

Catherine Cruver said...

Tacoma 4:40. no snow.

Matt said...

@BryanBlack - Chilly! And a Feliz Navidad Blanco to all if it all pans out, which *it won't*, at least not as shown...

Blog for Christ said...

Port angeles no snow yet either

LewisLucanBooks said...

10 miles SE of Chehalis. 600' elev. Started snowing at 1pm. By 5pm, had 2". Napavine Triangle :-). Lew

Johann von Puyallup said...

Puyallup 5:40 no snow -- strange that the radar has shown snow here for two hours already and not a flake
flakey radar?

Unknown said...



5:53 Arbor Heights, West Seattle. No snow.

Mark Allyn said...

Bellingham at about 6:15; no snow, lots of north/northeast wind/I can still see some stars peeking through the clouds.

Streets are bone dry so far. . . .

Mark

Mark Allyn said...

Bellingham at about 8 PM. No snow; moon is still visible through very thin clouds. Wind seems to have died down a wee bit.

Mark

Kat said...

Snow at SeaTac Airport from the first band that didn't dissipate from about 19:26 to 19:50.
Anticipating the next band of precipitation. Hopefully to start at 20:10ish?
Surfaces on runways have been reporting at below freezing.

Vegan Chubosaurus said...

North Seattle, 8:00. No snow whatsoever. Between this and the windstorm that wasn't, I'm developing an intensely personal dislike for all the Cliff Masses of the world. Particularly this one.

Ted Stern said...

Dry streets at the top of Maple Leaf so far (455 ft elevation).

sherrlock said...

No snow near Green Lake at 8PM.

Carla Ecland said...

....wait, Chehalis, has an airport?

Ruth said...

Finally some flurries in Queen Anne. Not impressive.

TrickyCoolJ said...

Well apparently High Point in West Seattle is the donut hole of snow.

Ward said...

A few flakes falling at Shoreline at 8:20PM.

Sean Williams said...

Olympia at 8:30 pm: 4 inches of snow so far and heavy snow still falling.

Freddy Carley said...

8:25pm. Rainier Beach and only a light dusting. Not currently snowing. I want more snow Cliff!

Joanna said...

LOL TrickyCoolJ! I used to live at 34th and Myrtle and got more snow than anyone else in the city limits. That was from 1987 to 2003 though. Had drifts over my car door handles once.

Unknown said...

Snowing in Mukilteo, Lynnwood and edmonds

parent999 said...

Just started in Montlake at 8:30. Later than expected because it's moving slower? Does that mean it will last longer and accumulate more?

Sara said...

North Seattle, Broadview. Heavy snow now.

Lauryth Johns said...

Snow started on Vashon, mid-island between 6:30 and 7:00pm. Now about three quarters of an inch. It's moving slower than I thought, but got here all the same.

RG said...

Started snowing in Gig Harbor at 6:30.....currently dumping snow (9:30)!

Ashley said...

Just started in Woodinville!

Chelsey Matley said...

Still snowing in shoreline!!

Chantelle said...

The "first band" never panned out here in Mukilteo. I saw about 3 flakes at 6 p.m. but that was it. Light snow began at 9-9:30, so the forecast was spot on for us. Still snowing but I don't expect we'll see more than a dusting.

craiger77 said...

Here on the coast in Newport, OR the temperature spiked about 15 degrees in 30 minutes around 4 and is now (10:45) at 52F so don't expect the snow to last.

Dennis The Tiger said...

Spotted at Bellevue College around 20:00.

Got to south Bothell around 21:15.

If I'm reading the radar right, it'll break up to scattered rain in an hour or so, with predictions of temps above freezing at about that point.

Colleen said...

No snow at 11pm in north Whatcom County; just our standard non-stop northeaster. Thursday temps in Bellingham were several degrees higher than farther north, and wind wasn't nearly as significant. Generally we don't get snow until/unless this wind dies down. Then there's a a light snowfall, after which the wind picks back up and wreaks havoc.

Rarity said...

2 inches in Queen Anne and snowing moderately at 11:15 pm

Ian and Lauren Hernandez said...

Steady snow in Fremont since 8:00, started snowing heavily around 9:30. I've measured 1-1/4 - 1-1/2 total accumulation as of 11:15.

David B. said...

2" on Bainbridge Island. Still snowing. Winslow area, 100' elevation.

Foo said...

And yet here you are. Why not put us out of your misery and pay attention to something you DO like. Or is it not that simple?

Brad said...

One inch in Wedgwood. Still coming dwn. 30 degrees.

Organic Farmer said...

That's the real weather news story!

riotdorrrk said...

coming down nicely in Green Lake. too bad it won't stay

Ruth said...

Still snowing in Shoreline at 2:40 am. Slow but steady.

Lori said...

Completely covered in 2 inches of snow here in Clearview!

longtimeneighbor said...

3:43am, 3ish inches and still snowing in Ballard. Beautiful!!

Brian Blackmore said...

NE 65th saw nothing before 8pm. It was calm at 1am except for a few people trying to learn to drive in the snow. 4:30am and it was snowing again.

Mikki Townshend said...

2 inches where I am on Bainbridge and still snowing at 5:45. Roads ploughed, school district closed, our bus route cancelled!

RLL said...

610am, barely 1/2 inch, slushy. downtown waterfront, Bremerton

paul said...

No rain yet and snow covering ground and side streets in greenwood

David B. said...

About 3" total on Bainbridge (Winslow area, 100 feet elevation) before it changed over to drizzle and started melting sometime between 2:00 AM and 4:30 AM.

Unknown said...

It's a winter wonderland out here in Duvall...beautiful!

Kevin said...

Approximately 1 inch in Bellingham at 7:15 am. Snowing lightly but still cold - 30 degrees and 22 dew point.

windlover said...

Haven't looked at the GFS yet.my son is hogging our computer to finish quarter final reports..what is it showing? Most forecasts for next week show super cold again but dry...when there is moisture it says rain....

Kelly said...

We got about 4 inches in Seabeck ... NICE AND BEAUTIFUL!!!!

Just AboveNOAA said...

Always dependent on exact geography, but from my point of view (north seattle), i'd say Professor Mass's snowmeggeon-2016 forecast was spot on. Came late, about an inch, melting away in the morning, ("just like she..." shaddup!) Well done!

Unknown said...

7-8 inches and still snowing west of Hood Canal at 500'.....

Mark Allyn said...

10:20 here in Bellingham (near Cornwall Park); about 1 inch on ground; very light breeze from south. Snow is starting to dampen. Stuck my arm out and felt no precip at all.

Mark

Gpacharlie said...

Accumulation of 5.7" at 1000' elevation 3 miles SSE of North Bend, WA at 10:30 am and still snowing very light and powdery snow.

Darn good forecasting Cliff. I bought tires last week because of your forecasting and sure glad I did.

Gpacharlie said...

DO YOU LOVE TO PLAY IN THE SNOW ?

❄️❄️❄️
Do you love to play in the snow but don't want to drive all the way to the Pass for fun? I shouldnt do this and let the secret out but fot Cliff Mass fans here it is. 30 minutes from Seattle is a wonderful State Park at Rattlesnake Lake. Exit off I-90 and go up the hill on Cedar Falls Way and at the end of the road is a beautiful park with about 6 inches on the ground right now, and they plow the road and parking lot. Have fun out there.

evie said...

I am a happy camper this morning. We have snow on the ground, and at about 500 feet elevation, just above Lake Goodwin, Northwest of Marysville, it is snowing. It may not all be snow, temp is 33, but it's snowing.

Ellen Baker said...

It's still snowing in Glacier - over 2" powder has accumulated since last night. It's warming right now; flakes are getting bigger and we may be heading back to 32/transition point. There are a lot of Weather Underground personal weather stations that report continuously via internet now. "Glacier West Central" is: https://www.wunderground.com/personal-weather-station/dashboard?ID=KWADEMIN7#history

I wonder if the U-crew makes use of the data. A number of us calibrate and cross-check.

Kevin said...

Starting to snow a bit heavier in Bellingham - temps still around 32 with dew point of 26 at my house on South Hill.

Karen Grooms said...

4" accumulation in Coyle, 230' elevation at tip of Toandos Peninsula in middle of Hood Canal. Simply gorgeous.

Unknown said...

Jambles.....

:)

Alex said...

First heavy snow in Redmond since February 2014. Wow.

Colleen said...

Didn't amount to much in north Whatcom County, in part because of the wind. Still, the dusting of white looks lovely. Concerned, though, about freezing temps over night and icy roads.

Next week is now showing up as cold temps and sunshine every day. Assuming that will be accompanied by more Fraser Valley outflow. What do you say, Cliff?

Gpacharlie said...

10" of fresh powder just up the hill from North Bend.

Ansel said...

On the Bothell-Mill Creek line it started about 10 pm and was about done by dawn. I'd say a scant two inches...

Mark Allyn said...

Stopped snowing here in Bellingham at about 4:30 PM; looks like clouds are thinning. However, there is still a breeze from the northeast. It seems that the Frazer outflow is still here in Bellingham. Snow in my yard (E. Victor and Guide Meridian across from Cornwall Park) is try (not wet/sticky), which makes me guess that temps here in Bellingham have yet to make it above freezing.

Mark

Jondroot said...

Cliff, it's after 5pm.. Friday. and we are getting freezing rain in Kent! What's taking so long for this cold air to get out?

Joanna said...

Hi Colleen! We got a couple of inches in my part of Whatcom county, and it snowed most of the day. Microclimates :)

Organic Farmer said...

About 1/4 inch of pitiful slush at the Admiralty....

Spent the chilly dark night reading December technical forecasts.

IMHO...... The real story is the potential to be kissed by a polar Vortex! Pacific decadal oscillation, totally dead blob, extream snow in Siberia, la Nina ... Perfect storm stuff for extremely cold infiltration. (Like record lows)

Scary stuff for those camping. Exciting for those with money to burn on heat.

Troy Otter said...

Dumping snow in North whatcom county...Fraser valley keeping it optimal for snow.

Colleen said...

Yep, as Troy said, on Friday evening decent snowfall is still decent here in north Whatcom County. Supposed to warm up a few degrees overnight & tomorrow, and the slush/freezing rain mix could be "interesting".

Joanna, when I said Friday's event didn't amount to much, I meant in relative terms. : ) We did get a couple of inches in my part of the county, too, but as is so often the case, snow here is accompanied by the northeaster & it doesn't settle evenly. Mostly just windy snow throughout the day, nothing noteworthy. More accumulations tonight, like Troy said, and we'll see how it plays out with wind + temps!

Scott K. said...

I'd like to learn more about what causes it not to snow when temps are below freezing.

In North Auburn, I left the house this (friday) morning when it was raining, temps outside were about 27f. I came home tonight and temps outside were about 29f and it's still raining.

Is it because of warmer air aloft? I figured we should be getting freezing rain if not snow at those temps.

Also, I have a friend who lives between renton and issaquah, they've been getting snow all day. Just a couple miles west of them it's bone dry. Totally weird patchy snow.

Mark Allyn said...

Bellingham finally turns to slush at about 9:45PM and north wind seems to be starting to slow down. I walked about 1 mile without falling from E. Victor St. to Downtown.

Mark

LewisLucanBooks said...

1:15 AM, Mon. 10 miles SE of Chehalis. 600' elev. It's SNOWING. Most of the snow from last week finally disappeared today. Loks like we're heading into a cold snap. A long one. Wonder how long it will hang on? Lew