December 2018 Weather in the Pacific Northwest

[van city]

#384forlife

#384forlife

That's what we live for.

[TT-SEA]

Long hair on women drive me crazy!

 

 

Did you happen to catch Ciara cheering on Russell Wilson at the game on Monday night? 

 

[Phil]

Don’t look now, but here’s the last frame of the 18z GEFS mean for 850mb temp anomalies.

 

Quite a signal for 384hrs out! #CueTheJawsMusic

 

[TT-SEA]

Don’t look now, but here’s the last frame of the 18z GEFS mean for 850mb temp anomalies.

 

Quite a signal for 384hrs out! #CueTheJawsMusic

 

 

 

Jaws music for Montana and Minnesota?    They know how to deal with cold in the middle of the winter.   

 

I know... I know... it will retrograde right over us.   Got it.  

[Phil]

The cold blob actually intensifies and expands southwestward from D12 to D16, which is unusual for an ensemble mean.

 

Usually, ensemble means will dampen pattern variability exponentially with time. So when you see an intensifying signal at-range (especially 2 weeks out) it’s worth paying attention to.

[TigerWoodsLibido]

The cold blob actually intensifies and expands southwestward from D12 to D16, which is unusual for an ensemble mean.

 

Usually, ensemble means will dampen pattern variability exponentially with time. So when you see an intensifying signal at-range (especially 2 weeks out) it’s worth paying attention to.

 

Don't do this to us...

[Phil]

[Phil]

^^ Watch the TPV migrate from Baffin Island to Alberta from D12 to D16. I don’t think I’ve ever seen that on an ensemble mean at this range before.

 

Whether or not it verifies is yet to be determined, obviously.

[TT-SEA]

Sorry brother, but I have a hunch. This is the start of the model madness.

 

You don’t see this type of (strengthening) cold signal on the GEFS very often, especially this far out.

 

 

 

Its good information... I like when you have a hunch.   

[umadbro]

With Phil it's always about 3 weeks out.

[TT-SEA]

With Phil it's always about 3 weeks out.

That might also be nature's fault!

[Requiem]

What exactly is the WRF useful for?

 

I like what it shows, a wishcaster's dream.

 

[Blizzard777]

Don’t look now, but here’s the last frame of the 18z GEFS mean for 850mb temp anomalies.

Quite a signal for 384hrs out! #CueTheJawsMusic

384 with jaws music changes everything

[Phil]

If there was already a build-up of Arctic air in Canada right now (before the retrograding waves initiate), then this would have very high potential. Much higher than last February.

 

But this time, thanks to the raging jet, Canada is a complete furnace beforehand. How quickly the source regions can “recover” is the big question in my mind.

[Perturbed Member]

What exactly is the WRF useful for?

 

I like what it shows, a wishcaster's dream.

 

 

 

Very good at busting and crushing your hopes and dreams. 

[Phil]

And the MJO timing is perfect for once.

 

Propagating towards the Maritime continent/IPWP right as wave-1 maxes out. Last February it was in phase-8 (WHEM) when you guys got your wintry stretch. And back in 2013, it was in phase-7 (dateline/warm pool forcing).

 

This timing actually..perfect.

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ECMF_phase_MANOM_51m_small.gif

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/CANM_phase_20m_small.gif

[Requiem]

Very good at busting and crushing your hopes and dreams. 

 

I figured!

[MR.SNOWMIZER]

Pic from today. This is a ridge above my place. 5000ft. Right now there is 9 inches at this spot and last year same time there was 25. Snow is really behind this year.

[Phil]

So this one is actually more interesting to me now than either of the last two events were, as far as western cold is concerned.

 

Again, there’s really only one question, and that’s the extent of the damage the ongoing jet extension does to the source region. Would be a pathetic way to screw it up.

[Requiem]

But honestly, I think tomorrow could be very blustery even for PDX. 35-45 mph gusts perhaps? As most models are trending the low more south (Central rather than N. Vancouver Island).

[Phil]

And the 12z CMC ensembles paint a similar picture.

 

[Deweydog]

I'm having "384" tattooed across my back.

[GHweatherChris]

I'm having "384" tattooed across my back.

Tramp stamp is the best option!

[Phil]

I'm having "384" tattooed across my back.

Of course you should never take the extended range stuff at face value. That would be absurd. But it’s a window with much higher potential. That much we can derive.

 

Keep in mind the reason(s) we run these perturbed ensembles. They help us isolate modeled weather/climate anomalies with a higher degree of statistical certainty. So when you see highly anomalous wave structures being modeled with *increasing* amplitudes at-range (which runs against statistical norms for ensemble spreads), and across multiple models, it’s something to watch.

 

Also, given the known factors (SSW and developing Maritime MJO wave) there is foundational support for an interesting period, as well.

[Frontal Snowsquall]

 

Did you happen to catch Ciara cheering on Russell Wilson at the game on Monday night?

 

I actually did see this part but it was too blurry for me to make out. Wilson is one lucky guy!

[Frontal Snowsquall]

 

This has to be the most advertised and anticipated Sudden Stratosphere Warming event in history.

 

#SSW

After what happened last year, everyone is becoming stratosphere junkie now.

 

I’m especially looking forward to the insane model swings that will envelop the wx-weeniesphere over the coming weeks. Gonna be madness.

I can honestly say that this is the most excited I've ever been in my life for an incoming SSW event.

[Bryant]

And the MJO timing is perfect for once.

 

Propagating towards the Maritime continent/IPWP right as wave-1 maxes out. Last February it was in phase-8 (WHEM) when you guys got your wintry stretch. And back in 2013, it was in phase-7 (dateline/warm pool forcing).

 

This timing actually..perfect.

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ECMF_phase_MANOM_51m_small.gif

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/CANM_phase_20m_small.gif

For sake of discussion, I fear we will barely miss our window of opportunity. Seems as though once the floodgates actually open, forcing will be pushing into the W Pac. You're obviously much more knowledgeable than I am, so please explain where my thinking is flawed

[Frontal Snowsquall]

[Bryant]

[Deweydog]

Of course you should never take the extended range stuff at face value. That would be absurd. But it’s a window with much higher potential. That much we can derive.

 

Keep in mind the reason(s) we run these perturbed ensembles. They help us isolate modeled weather/climate anomalies with a higher degree of statistical certainty. So when you see highly anomalous wave structures being modeled with *increasing* amplitudes at-range (which runs against statistical norms for ensemble spreads), and across multiple models, it’s something to watch.

 

Also, given the known factors (SSW and developing Maritime MJO wave) there is foundational support for an interesting period, as well.

Feels like we'll be ripe for some manner of blocking around New Year's.

[Phil]

For sake of discussion, I fear we will barely miss our window of opportunity. Seems as though once the floodgates actually open, forcing will be pushing into the W Pac. You're obviously much more knowledgeable than I am, so please explain where my thinking is flawed

It’s not necessarily flawed. But keep in mind the communication between the tropics and extratropics goes both ways. Extratropical forcings affect the MJO structure and how it is communicated, and vice versa. Convection near/over the IPWP is an efficient conduit to mass deposition across the NPAC in of itself (not to mention EAMT feedback), and there’s no necessity that the domain of divergence be constrained to within such a small range of longitude. Half of the issue is how the forcing is received peripherally, and that is of course wholly state-dependent.

 

In the case of 2018, we had an incredible, globally-integrated +MT/AAM uptake event late in November which has climaxed and is now terminating following the poleward propagation of the axis of received momentum via eddy transport. Looking forward, we have an extended stretch of -EAMT upcoming, which is like whiplash to the integrated state of momentum balance and will displace a crapload of mass into the NPAC and play on the waves’ phase speeds in conjunction with the intraseasinal forcing. And with the SSW feedback via the accelerated mass circulation/cooling+elevating tropical tropopause, you have a recipe for a deeper/slower MJO wave w/ very efficient exhaust.

 

Footnote: As it relates to AAM *tendency*, just for the sake of simplicity, I like to quote the old adage “every action has an equal and opposite reaction”. When you have large anomalies in AAM balance, the “backswing” is also going to be of higher amplitude. There is an unusually large excess of westerly momentum in the atmosphere right now relative to the rotation of the planet (in both hemispheres but especially the subtropical NH).

[Kayla]

After what happened last year, everyone is becoming stratosphere junkie now.

 

I’m especially looking forward to the insane model swings that will envelop the wx-weeniesphere over the coming weeks. Gonna be madness.

 

So true. They have officially raided my twitter feed!

[Phil]

Feels like we'll be ripe for some manner of blocking around New Year's.

I’m with you here. Big time.

[Phil]

[Phil]

Here’s the new EPS for January 1st - 5th.

 

Again, don’t take it verbatim, but note the trends in model guidance and the dynamic support (AAM drawdown from Eurasia, Indo-Pacific MJO, and the SSW). It’s undoubtedly a period to watch closely.

 

(BTW: This is the “cold loading pattern” that Flatiron was alluding to but misinterpreted).

 

[SilverFallsAndrew]

Very dynamic system affecting Tulsa, OK today. Was 58 this morning at 10am. but by mid afternoon temps had dropped to about 40 with heavy rain and strong northerly winds. Quite a raw nasty day with widespread 2-3" rain amounts. 

[Phil]

Do you have any websites/articles that explore at a higher level all the things you talk about? MJO/AAM/EAMT/SSW/tropical forcings/etc?

 

I'm not talking about the in-the-weeds dissertations I know you read - more of a laymens term type paper. Whenever I Google this type of stuff it always leads to lame duck readings that perhaps explain what it is but not how it effects things. I'm hoping you have a Goldilocks source you can share.

So like a source that explains these processes? Or a source with easy-to-decipher data/observations?

 

I’m not sure about the former, but I can definitely provide you with the latter.

[Blizzard777]

Very very quiet out there

 

47.7*

[Bryant]

Phil, check your FB messenger lol

[SilverFallsAndrew]

Some sort of encouraging trends today it seems.