February 2017 Observations and Model Discussion for the Pacific Northwest

[SilverFallsAndrew]

Major ensemble improvement on the 12z

[snow_wizard]

Not bad on the 12z GFS this morning. The ensemble has certainly trended cooler overall after the brief warm period also. The ECMWF ensemble shows the early stages of a colder pattern developing during week 2.

[snow_wizard]

In omak right now. There is more snow in cle elum and blewett pass than i have ever seen.

This would have been an amazing winter to live in the Cle Elum area. That area can have some of the best winters east of the Cascades due to cold air damming during offshore flow and resultant enhancement of snowfall.

[snow_wizard]

Hit 32 this morning, ground icy, power is back!

We had almost wind no during the entire event. This area is remarkably sheltered from south winds in many cases.

[wx_statman]

I meant below 38. And the record would be in the bag since a sub-38 low tomorrow is basically a given.

 

This morning is a case in point of why that's not a given. 

 

We'll see if we can work some pre-midnight magic again tonight. 

[ShawniganLake]

Dropped down to 29F this morning. 8-10" of snow remain after the SW winds of the previous 2 days.

[SilverFallsAndrew]

This morning is a case in point of why that's not a given. 

 

We'll see if we can work some pre-midnight magic again tonight. 

 

Never overestimate PDX lol.

 

34 at SLE

30 at EUG this morning

 

Burns hit 8. 

[Phil]

Incredible, really. One low above 38 since December 3rd. Immediately following our longest frost-free period on record.

So, are you convinced now that the PNW can still score in the winter department, from a historical standpoint? Or do we need a legitimate Arctic blast/CAA event to seal the deal?

[HighlandExperience]

So, are you convinced now that the PNW can still score in the winter department, from a historical standpoint? Or do we need a legitimate Arctic blast/CAA event to seal the deal?

Seattle still needs an arctic blast with flash freezing than I'll believe.

[Phil]

Seattle still needs an arctic blast with flash freezing than I'll believe.

If the late February/early March window doesn't deliver in that regard, one of the next two winters will, in my opinion.

[ShawniganLake]

If the late February/early March window doesn't deliver in that regard, one of the next two winters will, in my opinion.

I think that window has opportunity but it's tough to get flash freezing in Seattle in early March.

[Phil]

I think that window has opportunity but it's tough to get flash freezing in Seattle in early March.

True, but this certainly wouldn't hurt your chances, at least, given the effects on the tropical convection and mass circulations that should result down the road. The recent event timed well with the tropical response to the wave-1 SSW:

 

http://www.atmos.albany.edu/student/hattard/realtime/u_65N_10hpa.png

[wx_statman]

Never overestimate PDX lol.

 

34 at SLE

30 at EUG this morning

 

Burns hit 8. 

 

Usually wise words! But I'm feeling the mojo this winter.

 

We'll probably be down to at least 35 by midnight...and who knows, one of those intra-hour 37's before 4am might have been accurate this morning. 

[wx_statman]

So, are you convinced now that the PNW can still score in the winter department, from a historical standpoint? Or do we need a legitimate Arctic blast/CAA event to seal the deal?

 

I have to admit, this winter took me by surprise. 

 

There's no denying that our upper level/CAA abilities are diminished, however. That's to be expected in a warming climate. 

[Phil]

I have to admit, this winter took me by surprise.

 

There's no denying that our upper level/CAA abilities are diminished, however. That's to be expected in a warming climate.

Until the next big CAA event blasts in sometime within next few years.

 

Before 2013/14, most folks around here were thinking the exact same thoughts. Then a series of Dalton-minimum caliber blasts smacked us upside the head.

 

In reality, I think the climate change effect (either direction) is something like a degree or two, so while it does tilt the odds slightly, the various circulation networks are vastly more important to the nature of mobile polar high production. This is why in some of the recent solar grand minimums, gargantuan Arctic blasts occurred throughout the Mid-Latitudes, without a global temperature swing sufficient to explain their anomalous nature(s).

 

My hunch is you get nailed with a doozy by 2020, likely sooner than that (next winter?).

[Brennan]

Until the next big CAA event blasts in sometime within next few years.

 

Before 2013/14, most folks around here were thinking the exact same thoughts. Then a series of Dalton-minimum caliber blasts smacked us upside the head.

 

In reality, I think the climate change effect (either direction) is something like a degree or two, so while it does tilt the odds slightly, the various circulation networks are vastly more important to the nature of mobile polar high production. This is why in some of the recent solar grand minimums, gargantuan Arctic blasts occurred throughout the Mid-Latitudes, without a global temperature swing sufficient to explain their anomalous nature(s).

 

My hunch is you get nailed with a doozy by 2020, likely sooner than that (next winter?).

I vote this winter... perhaps the end of February.

[snow_wizard]

True, but this certainly wouldn't hurt your chances, at least, given the effects on the tropical convection and mass circulations that should result down the road. The recent event timed well with the tropical response to the wave-1 SSW:

 

 

Very interesting how our big change to colder weather came right after it tanked the first time.

[snow_wizard]

Until the next big CAA event blasts in sometime within next few years.

 

Before 2013/14, most folks around here were thinking the exact same thoughts. Then a series of Dalton-minimum caliber blasts smacked us upside the head.

 

In reality, I think the climate change effect (either direction) is something like a degree or two, so while it does tilt the odds slightly, the various circulation networks are vastly more important to the nature of mobile polar high production. This is why in some of the recent solar grand minimums, gargantuan Arctic blasts occurred throughout the Mid-Latitudes, without a global temperature swing sufficient to explain their anomalous nature(s).

 

My hunch is you get nailed with a doozy by 2020, likely sooner than that (next winter?).

 

I'm thinking you're right.  Perhaps with the likely Nina in 2018-19.  It would appear the QBO will line up nicely for us if we have warm / warmish ENSO next winter and cold ENSO the next.  We should be in some REALLY low solar activity the next few winters also.

[MossMan]

I vote this winter... perhaps the end of February.

I second that vote.

[Phil]

I'm thinking you're right. Perhaps with the likely Nina in 2018-19. It would appear the QBO will line up nicely for us if we have warm / warmish ENSO next winter and cold ENSO the next. We should be in some REALLY low solar activity the next few winters also.

Yeah. While the Niña/+QBO statistically performs much better than the Niña/-QBO, on the flip side of the coin, Niño/-QBO statistically performs better than Niño/+QBO. So if the system state transitions more niño-ish in 2017, a more -QBO would prime the tropical background more towards your favor.

 

Now, about next winter..there's a good chance we end up getting stuck with a completely neutral ENSO and mixed state QBO, which basically means the -QBO (easterly) wave is in the process of downwelling through the upper sigmas (at/above 30mb), but the lower sigmas (around 50mb) are still +QBO (westerly) and have yet to flip. This QBO wave appears to be a slow propagator relative to climatology, so exactly how quickly the QBO transitions will be consequential not just for your winter prospects, but for the evolution of the ENSO state itself, given some of the interactive feedback processes involved here.

 

So, if we are indeed handed a mixed QBO w/o a worthwhile ENSO/convective background, next winter will be a huge challenge to forecast, even more-so than this winter was, on both a seasonal and intraseasonal basis.

[Bryant]

Very interesting how our big change to colder weather came right after it tanked the first time.

The graph tanking indicates a wave 1 pattern which is capable of attacking the PV via Aluetian low/Siberian high. The warming of the strat due to wave 1 then causes MJO to ignite via cooling of the tropical trop/strat. The MJO then propagates into the EHem, an Aleutian ridge builds, we lose the favorable pattern to break down the PV, and the graph rises. Ironically, the pattern which delivers our cold (-EPO/-PNA) is an anti wave 1 pattern, which aids to strengthen the PV, which is why our cold blast hit after the graph bottomed out. Ideally, we want a full PV breakdown while we have an Aleutian low/Siberian high, then as the jet retracts and an Aleutian ridge builds, the arctic door is open

[snow_wizard]

The graph tanking indicates a wave 1 pattern which is capable of attacking the PV via Aluetian low/Siberian high. The warming of the strat due to wave 1 then causes MJO to ignite via cooling of the tropical trop/strat. The MJO then propagates into the EHem, an Aleutian ridge builds, we lose the favorable pattern to break down the PV, and the graph rises. Ironically, the pattern which delivers our cold (-EPO/-PNA) is an anti wave 1 pattern, which aids to strengthen the PV, which is why our cold blast hit after the graph bottomed out. Ideally, we want a full PV breakdown while we have an Aleutian low/Siberian high, then as the jet retracts and an Aleutian ridge builds, the arctic door is open

Incredible post! It has bee fun watching you become so knowledgeable.

[SilverFallsAndrew]

The persistence of the cold without a regional arctic blast was pretty impressive.

[Phil]

Incredible post! It has bee fun watching you become so knowledgeable.

He's turning into an intellectual monster. Nailed this winter too.

[snow_wizard]

He's turning into an intellectual monster. Nailed this winter too.

He really gets the why of it.

 

He certainly outdid Joe Bastardi by about 1000%.

[snow_wizard]

The persistence of the cold without a regional arctic blast was pretty impressive.

That really is impressive. Just about all of the cold we had more less seeped in, but in many cases was left sitting here for long periods of time. Probably about the coldest winter we could have with 850s barely ever getting to -10 or lower.

[Jesse]

This morning is a case in point of why that's not a given.

 

We'll see if we can work some pre-midnight magic again tonight.

Pretty likely. Tonight looks to clear a lot faster than last night.

 

Also possible that that midnight 36-37 carried over to today's obs.

[wx_statman]

The graph tanking indicates a wave 1 pattern which is capable of attacking the PV via Aluetian low/Siberian high. The warming of the strat due to wave 1 then causes MJO to ignite via cooling of the tropical trop/strat. The MJO then propagates into the EHem, an Aleutian ridge builds, we lose the favorable pattern to break down the PV, and the graph rises. Ironically, the pattern which delivers our cold (-EPO/-PNA) is an anti wave 1 pattern, which aids to strengthen the PV, which is why our cold blast hit after the graph bottomed out. Ideally, we want a full PV breakdown while we have an Aleutian low/Siberian high, then as the jet retracts and an Aleutian ridge builds, the arctic door is open

 

That's interesting. I've always wondered why some of our biggest cold waves were immediately followed by severe cold building in Alaska (early Feb 1950, early Jan 1969, Feb 1979). This might explain things.

[Phil]

He really gets the why of it.

 

He certainly outdid Joe Bastardi by about 1000%.

Haha, Joe Bastardi is a hilarious guy, but his inner weenie messed with him this winter.

 

To give JB credit, he's actually very good with medium range pattern recognition. He also doesn't have any biases when it comes to summer, so with a clear mind he performs quite well in the warm season.

 

Just have to tune him out when it comes to winter forecasts and politics.

[Phil]

That's interesting. I've always wondered why some of our biggest cold waves were immediately followed by severe cold building in Alaska (early Feb 1950, early Jan 1969, Feb 1979). This might explain things.

Yeah, the GOA vortex/+WPO is the precursory driver to the weaker stratospheric PV/wave-1 response in question here.

 

The stratospheric PV (ideally) is weakened by the +WPO/GOA vortex/-EAMT regime, so when the anticyclonic wavebreaking occurs following the tropical convective response, it's able to amplify poleward and upward, and self sustain for awhile.

 

A stronger stratospheric PV will eventually decapitate and overturn anticyclonic wavebreaks (which you see as the so-called "pinching off" of the ridge). Complicated process.

[TT-SEA]

Yeah. While the Niña/+QBO statistically performs much better than the Niña/-QBO, on the flip side of the coin, Niño/-QBO statistically performs better than Niño/+QBO. So if the system state transitions more niño-ish in 2017, a more -QBO would prime the tropical background more towards your favor.

 

Now, about next winter..there's a good chance we end up getting stuck with a completely neutral ENSO and mixed state QBO, which basically means the -QBO (easterly) wave is in the process of downwelling through the upper sigmas (at/above 30mb), but the lower sigmas (around 50mb) are still +QBO (westerly) and have yet to flip. This QBO wave appears to be a slow propagator relative to climatology, so exactly how quickly the QBO transitions will be consequential not just for your winter prospects, but for the evolution of the ENSO state itself, given some of the interactive feedback processes involved here.

 

So, if we are indeed handed a mixed QBO w/o a worthwhile ENSO/convective background, next winter will be a huge challenge to forecast, even more-so than this winter was, on both a seasonal and intraseasonal basis.

 

Neutral and low solar are a great combination here in general... in all seasons.   

[VancouverIslandSouth]

It's been interesting to see how much of a force the Fraser Valley outflow has been this year in spite of some rather unimpressive upper level air masses. Places in the valley have had such an incredible winter this year.

 

Melting out here today, it hasn't dropped below freezing since early Thursday morning though it cooled down a bit yesterday. Currently 46F and mostly sunny, quite a change from how things looked Wednesday afternoon.

 

http://i131.photobucket.com/albums/p286/jemeric/IMG_4156_zpsoigeqxru.jpg

 

http://i131.photobucket.com/albums/p286/jemeric/IMG_4126_zps2rojeykx.jpg

[Jesse]

Amazing how easy 50+ seems now that we've broken the seal.

[SilverFallsAndrew]

Amazing how easy 50+ seems now that we've broken the seal.

Isn't it like average now... Inversion season is over, only 42 up here today.

[Jesse]

Isn't it like average now... Inversion season is over, only 42 up here today.

Good catch! You are really starting to get a solid handle on this climate.

[VancouverIslandSouth]

Amazing how easy 50+ seems now that we've broken the seal.

 

I have yet to see a cherry tree in full blossom. I'm getting worried.

[snow_wizard]

The 18z looks very interesting indeed. A good signal for more GOA / Alaska blocking. Ensemble continues to improve as well.

[snow_wizard]

I think that window has opportunity but it's tough to get flash freezing in Seattle in early March.

The only true one I can think of is 1955. That one had a true blast with a nice Arctic front snowstorm. 1870 actually had one later in March, but that's going way back. Then of course there was an amazing event in 1865 also.

[Jesse]

Also possible that that midnight 36-37 carried over to today's obs.

Looks like that was the case. They recorded a low for today of 36 in the 2am hour.

 

http://w2.weather.gov/climate/getclimate.php?date=&wfo=pqr&sid=PDX&pil=CLI

 

So the record is already in the bag!

[Jesse]

Pretty impressive that PDX scored a high of 53 with such a cool airmass overhead. Two degrees warmer than our average high for the date.