December 2016 Observations and Model Discussion for the Pacific Northwest

[Front Ranger]

Someone between Seattle and Bellingham will see 6" tonight. That much I know! There should be a very healthy CZ. Just a matter of how much does it drop south.

[Deweydog]

To this day I still have never seen anything like that night here. I remember looking at the thermometer and it reading 8 degrees, wind blowing 40 trees broken and snapped off and drifts everywhere. For those of you that were here for that know how crazy it was.

Just wait 'til a week from Wednesday...

[Front Ranger]

To this day I still have never seen anything like that night here. I remember looking at the thermometer and it reading 8 degrees, wind blowing 40 trees broken and snapped off and drifts everywhere. For those of you that were here for that know how crazy it was.

 

Easily the most impressive (and earliest that I remember) Arctic front I've experienced, until Dec 2008 here.

[MossMan]

NAM still seems to also like the slower/weaker solution for Thursday.

King NAM!

[FroYoBro]

I guess it's possible. At this point it would be intensity-dependent.

 

It really looks like it is going to dry out during the evening. I would love to see a snow shower later, but don't think it is going to happen. 

[Jesse]

It really looks like it is going to dry out during the evening. I would love to see a snow shower later, but don't think it is going to happen.

Glad to see SOMEONE here giving us the harsh dose of reality we all need.

[Weather101]

Still light snow

[SilverFallsAndrew]

37 in downtown Silverton. About to head up the hill...

[HighlandExperience]

I like the optimism! I have a weird feeling the CZ won't materialize, but I would be happy to be wrong.

Wil see how good the EURO is tonight.

[Jesse]

37 in downtown Silverton. About to head up the hill...

I just passed out in anticipation then woke back up. Let us know when you get there!!!!

[BLI snowman]

To this day I still have never seen anything like that night here. I remember looking at the thermometer and it reading 8 degrees, wind blowing 40 trees broken and snapped off and drifts everywhere. For those of you that were here for that know how crazy it was.

 

Yeah, it was hawt.

[FroYoBro]

Glad to see SOMEONE here giving us the harsh dose of reality we all need.

I'm just saying what most of the models show. Just some real light showers around. Probably not good enough for snow. 

[Gradient Keeper]

NAM still seems to also like the slower/weaker solution for Thursday.

18z NAM has 522 thickness all the way down to Roseburg

[Jesse]

I'm just saying what most of the models show. Just some real light showers around. Probably not good enough for snow.

Sure it's a long shot. Even having a dusting going into a cold, clear night is nice though.

 

That heavy batch of precip not giving you anything?

[HighlandExperience]

If we don't see a CZ developing or already developed by the time the Euro comes out, it won't be happening. Nothing but radar between now and then (with a side of the HRRR).

The morning run showed a CZ right over king county.

[Front Ranger]

The Canadian ensemble mean was pretty good. Not quite as good as the GFS.

 

[Deweydog]

Sure it's a long shot. Even having a dusting going into a cold, clear night is nice though.

 

That heavy batch of precip not giving you anything?

I don't think there's gonna be much clearing tonight.

[Front Ranger]

Jeez, Jesse's just getting pounded with harsh reality. 

[Canadian guy]

How were the Euro ensembles for the mid range?

[Jesse]

I don't think there's gonna be much clearing tonight.

Probably enough broken cloudiness to let temps sneak to 32.

[Jesse]

Jeez, Jesse's just getting pounded with harsh reality.

I'm such an idiot!

[Front Ranger]

How were the Euro ensembles for the mid range?

 

They're just coming out now, at least for me.

[Jesse]

Euro ensemble mean looks awful at day ten. Raging westerly flow with 558dm heights. That's way out there though. A little better days 5-8.

[Deweydog]

Probably enough broken cloudiness to let temps sneak to 32.

Maybe, but there isn't much dry advection to speak of until tomorrow and things are pretty saturated.

 

But yeah, any clearing could lead to some sweet a** 31.8's.

[Weather101]

Up here in Vancouver BC, A snowfall warning was reissued.

[FroYoBro]

Sure it's a long shot. Even having a dusting going into a cold, clear night is nice though.

 

That heavy batch of precip not giving you anything?

 

It was just a bit too warm. I have seen plenty of snowflakes, but never really 100% snow. 

[Gradient Keeper]

Euro ensemble mean looks awful at day ten. Raging westerly flow with 558dm heights. That's way out there though. A little better days 5-8.

Yeah day 5-8 real promising.

[Deweydog]

Euro ensemble mean looks awful at day ten. Raging westerly flow with 558dm heights. That's way out there though. A little better days 5-8.

Flatiron did bequeath to us the knowledge that 96.8% of the time the Pacific ALWAYS wins.

[kokaneekidz]

Oh wow total 180. WRF reverses course and EURO does opposite

It appears the models cannot grasp whether the atmosphere will have enough juice in it to produce strong snowfall rates needed to produce accumulations worthy of chains required whips optional. Seems to be too little deep moisture at the moment.... C'mon mother nature be generous

[crf450ish]

Just stopped by Puyallup...

Typical...

[jcmcgaffey]

Take it with a grain of salt but the latest HRRR shows a CZ-like band developing over King County around hour 2 and is already past us by hour 5. Of course right when 80% of King County is too warm for snow. Dry pretty much the rest of the night.

 

http://www.tropicaltidbits.com/analysis/models/hrrr/2016120520/hrrr_ref_frzn_nwus_4.png

It looks like a convergence is starting to form in that same spot on the radar right now.

[Heavy Snow]

The JMA was one of the first models to see this current modified Arctic Blast so let's revisit what it's showing us in it's updated 12z run today. Good pattern setting up. We are close at days 7 and 10.

 

http://img.meteocentre.com/models/jma_amer_12/GZ_D5_PN_168_0000.gif

http://img.meteocentre.com/models/jma_amer_12/TT_GZ_UU_VV_168_0850.gif

http://img.meteocentre.com/models/jma_amer_12/GZ_D5_PN_240_0000.gif

http://img.meteocentre.com/models/jma_amer_12/TT_GZ_UU_VV_240_0850.gif

[MR.SNOWMIZER]

Good batch of new stuff coming in off coast. Low is spinning up nice.

[Gradient Keeper]

18z GFS

Begins.... NOW

 

Can we continue the trend with the GFS providing all kinds of goodies, cold air, and snow? 4 consecutive runs if the Drunk Uncle agrees. Unless he has a moment of sobriety. I hope not.

 

Feel free to play along (You may need to refresh pages)

Northwest view - http://www.tropicaltidbits.com/analysis/models/?model=gfs&region=nwus&pkg=mslp_pcpn_frzn&runtime=2016112912&fh=0&xpos=0&ypos=197

North America view - http://www.tropicaltidbits.com/analysis/models/?model=gfs&region=namer&pkg=z500_mslp&runtime=2016112912&fh=0&xpos=0&ypos=197

North Pacific view - http://www.tropicaltidbits.com/analysis/models/?model=gfs&region=npac&pkg=z500_mslp&runtime=2016112912&fh=0&xpos=0&ypos=197

Alaska view - http://www.tropicaltidbits.com/analysis/models/?model=gfs&region=ak&pkg=T850&runtime=2016112912&fh=0&xpos=0&ypos=197

[TT-SEA]

Its been snowing good here for the last couple hours despite very weak radar returns.

[Jesse]

It was just a bit too warm. I have seen plenty of snowflakes, but never really 100% snow.

We actually had 100% snow that stuck here a few hours ago. But now lighter precip is moving in and it's more of a mix.

[Deweydog]

Its been snowing good here for the last couple hours despite very weak radar returns.

That must be pretty frustrating.

[MikeInEverett]

18z doesn't wanna give the Puget Sound much of anything.. Comparison to 12z

 

12z:

http://www.tropicaltidbits.com/analysis/models/gfs/2016120512/gfs_asnow_nwus_5.png

 

18z:

http://www.tropicaltidbits.com/analysis/models/gfs/2016120518/gfs_asnow_nwus_5.png

[westcoastexpat]

3" at my sister's place in metro Vancouver

[seattleweatherguy]

18z doesn't wanna give the Puget Sound much of anything.. Comparison to 12z

 

12z:

http://www.tropicaltidbits.com/analysis/models/gfs/2016120512/gfs_asnow_nwus_5.png

 

18z:

http://www.tropicaltidbits.com/analysis/models/gfs/2016120518/gfs_asnow_nwus_5.png

Ouch glad it's one run.