December 2016 Observations and Model Discussion for the Pacific Northwest

[Heavy Snow]

Thank you.

 

Ideally, if I lived in the PNW, I'd want the PV highly perturbed, would root against a full SSW/PV destruction. A weak PV/NAM allows wave amplification to self-sustain more easily and amplify further.

 

However, a massive SSW/thermal wind reversal would rapidly cool the equatorial tropopause and ignite the MJO/equatorward tropical convection, which risks destroying the weak niña background convective/walker cell state. We saw this happen in January 2013, and it lead to (or technically was a reflection of) a cascade of events that semipermanently altered the H/W ratio(s), low frequency NPAC/PDO state, etc.

 

Thanks, that sounds right. Would you say that in December 2013 the Arctic Blast was a result of a full SSW/PV destruction which is the reason we got a big time cold blast but also very dry (except for that system that dropped down the coastline and hammered Central/Southern Willamette Valley) ? After that it took us 2 full months to have another chance again in February 2014.

[Gradient Keeper]

As I sit here it is currently 44.8 degrees near west Gresham. The sky features different shades of gray, each one with equal disinterest. All is well though. It's weather. I am very happy some of you are getting snow. I hope it somehow can stick around until Christmas Eve into Christmas morning. Keep posting the snowy pictures. Overall models beyond day 5 are still trying to resolve how to handle potential cut-off low.... A lot is going to change on future runs. Good things ahead with a wintry January we can finally believe in again. M J G A

[Heavy Snow]

Nothing better than just sitting and looking out the window with Christmas music playing on a day like this!

 

Wow, how many inches were you expecting and how much do you think you'll get when it's all said and done?

[TT-SEA]

Could be with a bit of elevation. My buddy is reporting 2-3 inches at about 400' near Lake Whatcom.

 

 

From the pictures I being sent from that same area... looks about right.

[SilverFallsAndrew]

From the pictures I being sent from that same area... looks about right.

 

Are you getting snow today?

[Phil]

Thanks, that sounds right. Would you say that in December 2013 the Arctic Blast was a result of a full SSW/PV destruction which is the reason we got a big time cold blast but also very dry (except for that system that dropped down the coastline and hammered Central/Southern Willamette Valley) ? After that it took us 2 full months to have another chance again in February 2014.

There wasn't a SSW/PV breakdown event in 2013/14. Arguably, the PV was stronger than ideal that winter, which assisted in keeping that Hudson Bay vortex planted firmly through the majority of Nov-Mar.

[SilverFallsAndrew]

There wasn't a SSW/PV breakdown event in 2013/14. Arguably, the PV was stronger than ideal that winter, which assisted in keeping that Hudson Bay vortex planted firmly through the majority of Nov-Mar.

Yet the PNW had two of our most significant arctic outbreaks in the past decade that winter. 

[Phil]

Yet the PNW had two of our most significant arctic outbreaks in the past decade that winter.

 

The PV/NAM was perturbed significantly on numerous occasions that winter, it just wasn't destroyed. There's a difference between a perturbed PV/NAM and a SSW/PV breakdown.

 

In a Niña convective background, generally a SSW/PV breakdown (aloft) isn't required unless it's a true unrelenting monster. An example of this would be 1988/89, where the SSW event that began in mid/late January dropped the dominos and I'm sure you know what followed that event..

[Prairiedog]

Winthrop almost at 1'

[TT-SEA]

Are you getting snow today?

 

 

Some snow... very wet.   Sticks for awhile when it comes down hard and then melts somewhat when it slows down.   Just some slush on the grassy areas.

[Skagit Weather]

Hasn't been accumulating here for a while, more like what falls replenishes what melts. All it needs to do is snow for another hour or so and then I can hope that the cooler and drier air will preserve it for a day or two.

[SilverFallsAndrew]

Rip Carrie Fisher

[Heavy Snow]

There wasn't a SSW/PV breakdown event in 2013/14. Arguably, the PV was stronger than ideal that winter, which assisted in keeping that Hudson Bay vortex planted firmly through the majority of Nov-Mar.

Ok thanks. I wasn't sure what the exact details were in that situation.

[SilverFallsAndrew]

She's not dead you a**.

Near death, they may just be waiting for the ME, a developing situation.

[Phil]

I think the 18z GFS is going to be even blockier and colder than the 12z, at least over the US as a whole. Already a more amplified Eurasian ridge by 96hrs, PV weaker as well.

 

The 80s are back, y'all.

[Fircrest]

Finally turned to all snow here about 10 minutes ago.  Too warm to stick with it being 35° currently.  I'm at 340'. I apprecitate all the model analysis you guys do...and the comedy!  Sure hope Jim gets some snow! 

[Jesse]

Rip Carrie Fisher

What is wrong with you?

[TT-SEA]

The coastal radar and the PDX radar both look absolutely pathetic.

[snow maniac]

Back to mix precipitation after several hours of good snow, hope it turns back

[SilverFallsAndrew]

What is wrong with you?

What are you talking about, sorry I misread a headline that said "near death."

[Winterdog]

Snowed all day long here and still is snowing with a temp of 33. Half inch accumulation on grass etc. If we can stay out of the rain till Monday I will be happy with some snow on the property for Christmas. Jim came through on this one. He persevered through ridicule from some of us and I hope he is accumulating some for himself. If I had some humble pie I would eat it but all I have is pumpkin. Oh well it'll do I suppose.

[Phil]

Interesting..this run reflects more wave driving into the stratosphere but is slightly flatter in NPAC. Will have to see how it all balances out.

[Gradient Keeper]

Snowed all day long here and still is snowing with a temp of 33. Half inch accumulation on grass etc. If we can stay out of the rain till Monday I will be happy with some snow on the property for Christmas. Jim came through on this one. He persevered through ridicule from some of us and I hope he is accumulating some for himself. If I had some humble pie I would eat it but all I have is pumpkin. Oh well it'll do I suppose.

Jim for President!

 

M

J

G

A

 

Make Jim Great Again !!!!

[TT-SEA]

Jim for President!

 

M

J

G

A

 

Make Jim Great Again !!!!

 

 

I have been talking about this event for 3 or 4 days when Jim was still being negative.   He only latched onto the idea last night.  

[MossMan]

What is your elevation?

 

Just under 300'. This was about an hour ago. Probably over 2" now with moderate snow still falling. Don't judge my snowman making skills...I'm out of practice it's been so long.

[SilverFallsAndrew]

Just under 300'. This was about an hour ago. Probably over 2" now with moderate snow still falling. Don't judge my snowman making skills...I'm out of practice it's been so long.

Cute kid

[MossMan]

Cute kid

Thanks! She was loving it!!! First real snow that we could actually make a snowman with since she has been alive (she's going on 3 in Feb.

[Gradient Keeper]

Just under 300'. This was about an hour ago. Probably over 2" now with moderate snow still falling. Don't judge my snowman making skills...I'm out of practice it's been so long.

Cute Snowman! and the little rug rat is kind of cute too. SNOW!!!! It looks like Winter! It must be wonderful especially as Christmas nears.

[Gradient Keeper]

I have been talking about this event for 3 or 4 days when Jim was still being negative.   He only latched onto the idea last night.  

M

T

G

A

 

Make TIM Great Again????

[The Swamp]

Just under 300'. This was about an hour ago. Probably over 2" now with moderate snow still falling. Don't judge my snowman making skills...I'm out of practice it's been so long.

Cool man! Building snow people is fun stuff.

[SilverFallsAndrew]

Thanks! She was loving it!!! First real snow that we could actually make a snowman with since she has been alive (she's going on 3 in Feb.

Girls are the best, all three of my kids are girls. Hoping the next one is too.

[Gradient Keeper]

Thanks! She was loving it!!! First real snow that we could actually make a snowman with since she has been alive (she's going on 3 in Feb.

February here too. It made the arctic blast/snow in 2014 that much sweeter as it occurred on my Birthday.

[ShawniganLake]

Thanks! She was loving it!!! First real snow that we could actually make a snowman with since she has been alive (she's going on 3 in Feb.

Took my wife for an ultrasound this morning. We are having a girl, due in May.

[SilverFallsAndrew]

Took my wife for an ultrasound this morning. We are having a girl, due in May.

Congrats!

[SilverFallsAndrew]

Backdoor action on the 18z

[ShawniganLake]

Backdoor action on the 18z

Looks like it's going places after 240 hrs too. Trying a further retrogression

[Gradient Keeper]

 18z Daily Drunk Uncle report

For what it's worth($1.24?) 18z 500mb comes around nicely after day 9 with a major backdoor blast after that point.

 

http://www.tropicaltidbits.com/analysis/models/gfs/2016122318/gfs_T850_nwus_42.png

 

http://www.tropicaltidbits.com/analysis/models/gfs/2016122318/gfs_T850_nwus_44.png

[Weather101]

Took my wife for an ultrasound this morning. We are having a girl, due in May.

Congrats dude!

[Gradient Keeper]

Took my wife for an ultrasound this morning. We are having a girl, due in May.

Congratulations to you both! That is terrific

[TT-SEA]

Took my wife for an ultrasound this morning. We are having a girl, due in May.

 

 

I am going to run out of likes for the day with all the snow pics and family announcements.