September 2016 Observations and Model Discussion for the Pacific Northwest

[snow_wizard]

Two weeks out??    Come on.

 

In reality it shows up on the models much sooner than that, and the GFS and ECMWF have had very similar ideas on how it will develop and track.  We'll see, but I think this has an above average shot at verifying for how far out it is.

[Phil]

Dang, the HiRes GFS takes would-be Matthew down into the mid-890mb range. That'd be a doozy.

[stuffradio]

6Z ALERT 6Z ALERT! 6Z is a weenies paradise... how is no one talking about it!?

 

524 thickness at hour 324 and -7 850mb for SW BC...

[TT-SEA]

6Z ALERT 6Z ALERT! 6Z is a weenies paradise... how is no one talking about it!?

 

524 thickness at hour 324 and -7 850mb for SW BC...

 

 

Great ensemble support.  The operational run is that green line of doing its own thing at the bottom.  

 

http://old.wetterzentrale.de/pics/MT8_Seattle_USA_ens.png

[Weather101]

Grey start too the day

[TT-SEA]

To his credit, this wave is entering a very favorable environment, hence the model agreement. We're talking 30C+ SSTs, and a CCKW superimposition there.

 

This one has legs, IMO.

 

 

EPS control run shows it curving northward east of Florida and up the East Coast in 2 weeks.

[Bryant]

Much can change in 2 days let alone 2 weeks.

How's that CFS looking?

[Bryant]

Great ensemble support. The operational run is that green line of doing its own thing at the bottom.

 

http://old.wetterzentrale.de/pics/MT8_Seattle_USA_ens.png

He looks to be just having some fun, no surprise you're the one to shut it down though!

[Jesse]

How's that CFS looking?

45 days of warmth and ridging. Time for the cold freaks to start popping the Prozac.

[TT-SEA]

He looks to be just having some fun, no surprise you're the one to shut it down though!

 

So am I, Bryant.

[Bryant]

45 days of warmth and ridging. Time for the cold freaks to start popping the Prozac.

It's a good thing the accuracy has been through the roof lately!

[TT-SEA]

How's that CFS looking?

 

 

Very warm for most of October on the latest run!     Expect the opposite on the next run.

[TT-SEA]

It's a good thing the accuracy has been through the roof lately!

 

That was a forecast?

 

Never made a forecast for September or October.   

 

Just reporting what the CFS and ECMWF weeklies showed at the time.   Good thing their accuracy has been through the roof lately!   

[Jesse]

It's a good thing the accuracy has been through the roof lately!

 

Only when it shows things we think will upset our mortal enemies!

[Bryant]

6Z ALERT 6Z ALERT! 6Z is a weenies paradise... how is no one talking about it!?

 

524 thickness at hour 324 and -7 850mb for SW BC...

It's a welcomed sight to already be seeing snow producing patterns in the fantasy range

[snow_wizard]

Pretty cold looking 12z as well.

[TT-SEA]

Only when it shows things we think will upset our mortal enemies!

 

 

Only you have this battle... and its really with nature and not me.      

[snow_wizard]

It's a welcomed sight to already be seeing snow producing patterns in the fantasy range

 

FWIW 1971 has been popping up as an analog recently.  Nice Arctic outbreak in Oct 1971.  What the 6z shows would even be a bit earlier than 1949, but who knows.

[Phil]

EPS control run shows it curving northward east of Florida and up the East Coast in 2 weeks.

Whether it makes landfall or not is another story. I could see it getting pulled north around 70-75W as the TUTT retrogrades.

[TT-SEA]

August and September will end up almost identical in terms of departures at SEA as 2015.

[TT-SEA]

FWIW 1971 has been popping up as an analog recently.  Nice Arctic outbreak in Oct 1971.  What the 6z shows would even be a bit earlier than 1949, but who knows.

 

 

Honestly... If I was betting money I would take October being above normal at SEA.     I would not have made that bet about September.

 

Any takers?  

[Phil]

Mega-blocking on the 12z GFS. Just not oriented perfectly.

 

Almost looks like a repeat of the progression October 2013, just faster and with more -NAO.

[snow_wizard]

Mega-blocking on the 12z GFS. Just not oriented perfectly.

 

Almost looks like a repeat of the progression October 2013, just faster and with more -NAO.

 

Something very special is going on here. 

[TT-SEA]

Tuesday and Wednesday look great now... some runs a couple days ago had clouds and some rain.

 

http://s11.postimg.org/71fwzwgo3/intcld_60_0000.gif

 

http://s9.postimg.org/hw8hsnk9b/intcld_84_0000.gif

[Phil]

Honestly... If I was betting money I would take October being above normal at SEA. I would not have made that bet about September.

 

Any takers?

Didn't you bet me $5 that September would be warmer than average? I remember getting myself into a silly protracted debate with you about it.

[TT-SEA]

Didn't you bet me $5 that September would be warmer than average? I remember getting myself into a silly protracted debate with you on it.

 

I never bet anything on September.   I had no idea.   

[Jesse]

Definitely looking like a pretty slow cooldown next week. 12Z GFS shows PDX back in the upper 70s Wednesday after dropping close to 75 Tuesday. Not much of a crash with a slow moving low and lots of SW flow ahead of it. Models seem to keep trending slower and slower as well.

[Phil]

I never bet anything on September. I had no idea.

Okay. You seemed pretty confident about it, but maybe I'm remembering stuff wrong.

 

As I said previously, I have no idea how October will turn out, and frankly I don't what you're seeing that makes you so confident. I'm leaning towards something normalish overall, given there's likely to be some variability and possibly very heavy blocking somewhere through the month. This is a complicated one, however, especially given what's going on with the IO/IndoChina convection/Hadley Cell and what looks to be an antecedent tendency for poleward anticyclonic wave breaking.

[TT-SEA]

Okay. You seemed pretty confident about it, but maybe I'm remembering stuff wrong.

 

As I said previously, I have no idea how October will turn out, and frankly I don't what you're seeing that makes you so confident. I'm leaning towards something normalish overall, given there's likely to be some variability and possibly very heavy blocking somewhere through the month. This is a complicated one, however, especially given what's going on with the IO/IndoChina convection/Hadley Cell and what looks to be an antecedent tendency for poleward anticyclonic wave breaking.

 

 

I have no idea either... but I am feeling like it will be warm right now.

 

Jim's over-confidence in cold is another tell-tale sign as well.   That is actually true.

[TT-SEA]

12Z GFS operational still has almost no ensemble support.

 

http://old.wetterzentrale.de/pics/MT8_Seattle_USA_ens.png

[snow_wizard]

The first third of October is looking pretty chilly right now.  I actually think we have a reasonable shot at a period of much below normal temps at some point during the month.  I'm becoming more confident October will be to my liking, but not certain yet.  Pretty interesting that 1984 and 1971 have been recurring analogs and both of those had Arctic air and snow during October.

[snow_wizard]

Honestly... If I was betting money I would take October being above normal at SEA.     I would not have made that bet about September.

 

Any takers?  

 

Gutsy call at this point.

[Phil]

I have no idea either... but I am feeling like it will be warm right now.

 

Jim's over-confidence in cold is another tell-tale sign as well. That is actually true.

I think it's reasonable to have some level of confidence in blocking at this point. Obviously it's not a given that it'll last through the month, but strong blocking over the pole or EPO/GOA domains in October is highly correlated to great winters in the western half of the US. Plus, there's the fact that a +QBO during a -ENSO winter is highly correlated to stronger NPAC blocking overall.

 

Also, the lower/middle level stratPV (up to ~20mb, at least), has been much weaker than any other +QBO year I can find, at this stage of the game. This seems to be a result of consistent poleward mass/momentum transport under favorably oriented wave driving, and a strong post-niño BDC pumping O^3 into the polar stratosphere. Very peculiar, hopefully it continues!

[snow_wizard]

I think it's reasonable to have some level of confidence in blocking at this point. Obviously it's not a given that it'll last through the month, but strong blocking over the pole or EPO/GOA domains in October is highly correlated to great winters in the western half of the US. Plus, there's the fact that a +QBO during a -ENSO winter is highly correlated to stronger NPAC blocking overall.

 

Also, the lower/middle level stratPV (up to ~20mb, at least), has been much weaker than any other +QBO year I can find, at this stage of the game. This seems to be a result of consistent poleward mass/momentum transport under favorably oriented wave driving, and a strong post-niño BDC pumping O^3 into the polar stratosphere. Very peculiar, hopefully it continues!

 

Do you think the abnormally low IOD is a good sign as well?  Right now it is tanked.

[snow_wizard]

Definitely looking like a pretty slow cooldown next week. 12Z GFS shows PDX back in the upper 70s Wednesday after dropping close to 75 Tuesday. Not much of a crash with a slow moving low and lots of SW flow ahead of it. Models seem to keep trending slower and slower as well.

 

We'll see.  The WRF still shows a good drop on Tuesday.

 

Your post has kind of an unwarranted gloomy ring to it.

[Phil]

Do you think the abnormally low IOD is a good sign as well? Right now it is tanked.

Yeah, I think a cool/quiet IO in general is a good thing. We haven't seen a sleepy IO during a Niña/-ENSO year in a long time.

 

Was very common in the early/mid 1980s, however.

[TT-SEA]

Gutsy call at this point.

Then we should bet.

[Phil]

The cool/quiet IO is something more typical in -AMO eras, as they usually go hand-in-hand. I'm definitely leaning towards using 1980s analogs, though the polar stratosphere/BDC is nothing like what is was then. Lower solar and significant differences in upper atmospheric chemistry will make a difference..what sort of difference remains to be seen.

[TT-SEA]

Gorgeous day.   

 

Thinking about forgetting the Seahawks game and taking the boat out with the kids.  

[Jesse]

We'll see. The WRF still shows a good drop on Tuesday.

 

Your post has kind of an unwarranted gloomy ring to it.

Just reporting the trends. I will always gladly point it out if things trend faster/cooler with troughing too.

 

The only thing really in jeopardy now is PDX finishing the month -2 or better.