PNW November 2021 Wx Obs/Discussion

[GHweatherChris]

How can someone get away with posting actively from 2 different accounts on here... just curious.

[SouthHillFrosty]

Just now, GHweatherChris said:

How can someone get away with posting actively from 2 different accounts on here... just curious.

Run it through a vpn to block your IP address 

[GHweatherChris]

1 minute ago, SouthHillFrosty said:

Run it through a vpn to block your IP address 

It was a facetious question, but it is happening by someone without recourse.

[Phil]

11 minutes ago, bainbridgekid said:

Nine times out of ten that Winter’s large scale pattern would have resulted in a very good Winter here. Tiny details just kept screwing most people below 800 feet.

Lack of upstream amplification was the primary killer. Could be a challenge again this winter.

Then again I suppose that could be said about the majority of winters in the post-1998 era.

[Deweydog]

2 minutes ago, Phil said:

Lack of upstream amplification was the primary killer. Could be a challenge again this winter.

Then again I suppose that could be said about the majority of winters in the post-1998 era.

I don’t think we have had a winter in my weenie lifetime where there has been enough upstream blocking to our liking.

2007-08 had more than people are willing to give it credit for.  Fine details just didn’t shake out.

[Phil]

5 minutes ago, Deweydog said:

I don’t think we have had a winter in my weenie lifetime where there has been enough upstream blocking to our liking.

2007-08 had more than people are willing to give it credit for.  Fine details just didn’t shake out.

Did it, though? That was a +EPO/+NPO winter through and through. Sure there was a persistent -PNA, broad Aleutian ridging, etc, but that seldom delivers the goods by itself.

Especially nowadays in the +NAM era, it is a very difficult pattern to make work. The only exceptions post-WWII were +QBO/W-shear.

[snow_wizard]

The cooling trend on the GFS for next Monday night is quite remarkable.  The run to run change vs the 18z is -20 in some cases.

[Joshua Lake Oswego]

Getting perilously close to a Portland bust. Still looking solid. For now.
 

[RentonHill]

00z GEFS thru 240

[RentonHill]

00z GEFS - 850 temp anomaly - hr240

 

[TigerWoodsLibido]

GFS is boring. Less than an inch of rain for the next week or so. Pretty big dropoff and we're still in extreme drought. 

[Phil]

One look at 2007/08 versus 2008/09 and it’s clear what went wrong with the former.

Very hard to dislodge the TPV with such a flat Aleutian ridge. Compare that to amplification in 2008/09.

 

[snow_wizard]

21 minutes ago, Phil said:

Lack of upstream amplification was the primary killer. Could be a challenge again this winter.

Then again I suppose that could be said about the majority of winters in the post-1998 era.

My money is on at least slightly more amplification this winter.  If nothing else just because this -QBO isn't as strong as 2007 and is having a much later onset at the 50mb level.  This year just has a different feel to it than most recent years.

[snow_wizard]

5 minutes ago, Phil said:

One look at 2007/08 versus 2008/09 and it’s clear what went wrong with the former.

Very hard to dislodge the TPV with such a flat Aleutian ridge. In 2008/09 there was a notable poleward amplification.

 

It wouldn't have taken much to make 2007-08 much better though.  I think that winter is at high end of the envelope for possible EPO outcomes this winter.  We'll know soon enough.

[snow_wizard]

7 minutes ago, TigerWoodsLibido said:

GFS is boring. Less than an inch of rain for the next week or so. Pretty big dropoff and we're still in extreme drought. 

I'm done looking for rain.  Now it's all about cold.  There certainly is some of that on this run.

[bainbridgekid]

7 minutes ago, Phil said:

One look at 2007/08 versus 2008/09 and it’s clear what went wrong with the former.

Very hard to dislodge the TPV with such a flat Aleutian ridge. Compare that to amplification in 2008/09.

 

Very interesting maps. You’ll rarely see enough amplification over the course of three months on a map like that though. There was plenty of time in 07/08 when the ridge amplified enough that we normally would have seen the goodies. If that Winter had been 2 degrees cooler Seattle would have seen like 20 inches of snow and outlying areas would have seen 30-40”.

[SouthHillFrosty]

Call me when it will actually rain 

[Deweydog]

17 minutes ago, Phil said:

Did it, though? That was a +EPO/+NPO winter through and through. Sure there was a persistent -PNA, broad Aleutian ridging, etc, but that seldom delivers the goods by itself.

Especially nowadays in the +NAM era, it is a very difficult pattern to make work. The only exceptions post-WWII were +QBO/W-shear.

KISS…

We had two extremely favorable patterns in late November and the second half of January. If the finer details during one or both of those periods get tweaked toward the sexy, that winter gets looked at through an entirely different lens.

[Anti Marine Layer]

1 hour ago, Deweydog said:

I seriously think if Tim and Chris’s lips touch, the forum will instantly cease to exist and our climate will immediately revert to the mid 19th century.

 No more worries about climate change if that happens. 

 

[Phil]

12 minutes ago, snow_wizard said:

My money is on at least slightly more amplification this winter.  If nothing else just because this -QBO isn't as strong as 2007 and is having a much later onset at the 50mb level.  This year just has a different feel to it than most recent years.

You could be right. I hope you are..I’d love to avoid repeating 2007/08. I’m not making a call either way.

I’m just pointing out that the large scale pattern evolution has matched 2007/08 extraordinarily well, and that we shouldn’t wishcast it away as a possible outcome.

How it ultimately unfolds is yet to be determined, obviously.

[snow_wizard]

6 minutes ago, bainbridgekid said:

Very interesting maps. You’ll rarely see enough amplification over the course of three months on a map like that though. There was plenty of time in 07/08 when the ridge amplified enough that we normally would have seen the goodies. If that Winter had been 2 degrees cooler Seattle would have seen like 20 inches of snow and outlying areas would have seen 30-40”.

Indeed.

I have been talking a lot about 1970 which was a slightly more amplified version of 2007-08.  It too was near solar minimum, La Nina, and -QBO.  Besides that it has matched the CPC analogs many more times than 2007 recently.

[snow_wizard]

1 minute ago, Phil said:

You could be right. I hope you are..I’d love to avoid repeating 2007/08. I’m not making a call either way.

I’m just pointing out that the large scale pattern evolution has matched 2007/08 extraordinarily well, and that we shouldn’t dismiss it as a possible outcome. That seems like wishcasting to me.

How it ultimately unfolds is yet to be determined, obviously.

I'm just saying that was a pretty extreme case of +EPO that winter.  This winter has a good chance of doing better.  For one thing recent winters have been quite a bit better on the whole than what we saw in the early part of this century.

I did a composite of the last 3 weeks and compared it to the same period for 1970 and it's a great match to this year.  Better than 2007.

[luminen]

1971-1972 repeat incoming!

[jcmcgaffey]

Seattle is at 9” of rain in the last 5 weeks with lots more to come. I have to say this has been one of the more consistent stretches of rain I can remember. It’s been very consistent with most days having considerably decent rainy totals. 

[Gradient Keeper]

00z ECMWF Day 1

[Gradient Keeper]

Day 2

[Phil]

19 minutes ago, Deweydog said:

KISS…

We had two extremely favorable patterns in late November and the second half of January. If the finer details during one or both of those periods get tweaked toward the sexy, that winter gets looked at through an entirely different lens.

The second half of January had the same problem, though.

This is textbook rossby wave dispersion, with the in-situ +EPO/+NPO background state contributing to the lack of wholesale meridional displacement of the TPV.

Yes the GOA ridge looks “amplified” on the surface, but what is going on under the hood tells a much different story. This isn’t easy to convey visually, unfortunately.

[Gradient Keeper]

Day 3

[SilverFallsAndrew]

There are some on here who dream of January 2008.

[Gradient Keeper]

Rainfall totals ending 4 PM Friday

[Phil]

28 minutes ago, bainbridgekid said:

Very interesting maps. You’ll rarely see enough amplification over the course of three months on a map like that though. There was plenty of time in 07/08 when the ridge amplified enough that we normally would have seen the goodies. If that Winter had been 2 degrees cooler Seattle would have seen like 20 inches of snow and outlying areas would have seen 30-40”.

Yes, I believe you are correct about that.

I was specifically highlighting the mean state. Because the subseasonal pattern variability in question generally arises from/through the mean/low frequency state, which can dictate many aspects of the evolution.

The challenges in mid/late January 2008 were dynamically linked to the challenges posed by the shoddy low frequency/mean state that entire winter.

[SilverFallsAndrew]

I do remember being back from college in December 2007 and it snowing almost an inch on Christmas Day in Silverton. 

[SilverFallsAndrew]

FWIW January 2008 is tied (2013) for the coldest January at SLE between 1993 and 2017... 

[Phil]

25 minutes ago, snow_wizard said:

Indeed.

I have been talking a lot about 1970 which was a slightly more amplified version of 2007-08.  It too was near solar minimum, La Nina, and -QBO.  Besides that it has matched the CPC analogs many more times than 2007 recently.

And that could absolutely hold true this winter.

Again, all I’m saying is a 2007/08 type outcome (or even warmer/more zonal) is also a distinct possibility, and that we shouldn’t be so quick to dismiss it.

[Gradient Keeper]

Day 4

[Gradient Keeper]

Day 5

[SilverFallsAndrew]

4 minutes ago, Phil said:

And that could absolutely hold true this winter.

Again, all I’m saying is a 2007/08 type outcome (or even warmer/more zonal) is also a distinct possibility, and that we shouldn’t be so quick to dismiss it.

1999-2000 sticks in my mind as more of a worse case scenario. 

[Gradient Keeper]

Day 6

[Skagit Weather]

The rain monster in the North Cascades seems to be loving this most recent forecast.

[snow drift]

41 minutes ago, bainbridgekid said:

Very interesting maps. You’ll rarely see enough amplification over the course of three months on a map like that though. There was plenty of time in 07/08 when the ridge amplified enough that we normally would have seen the goodies. If that Winter had been 2 degrees cooler Seattle would have seen like 20 inches of snow and outlying areas would have seen 30-40”.

Was great above 1000 feet