My 2022-23 winter outlook & "what went wrong" Post-mortem

[Terpeast]

Okay here goes, back in the game. Dusting off my research skills and we'll see how it goes. 

Outlook is based on 2 things:

- Backward looking indicators using historical analogs for La Nina, +QBO, -PDO, -IOD, and high solar activity
- Forward looking indicators such as atlantic SSTs and wildcards like high stratosphere vapor content (Hunga Tonga)

My best analogs are:

- 2000-01 (no surprise)
- 2011-12
- 1985-86

I've also looked at 2017-18 and 2008-09, but didn't put a whole lot of weight on them. 

I was going to look at hurricane activity and years of low ACE, but I threw that out the window since things have been picking up in the atlantic.

My DFJ maps using my analogs:

 

 

Commentary:

I expect La Nina to maintain moderate through January and then weaken into March, when everything also trends neutral. This outlook also banks on a milder than normal November, then as the -IOD trends toward neutral, the winter will become milder (especially February) as we go on after a cold start.

Just based on these analogs alone, this is not supposed to be a productive winter. 

BUT... based on recent trends in the stratosphere and model forecasts, there's a chance that we may get a little bit of help from a negative -NAO if and whenever the pacific cooperates.

The opposing factor is high solar activity and +QBO, but we can have a decent winter despite those (e.g. 13-14 & 14-15). 

I don't see the entire eastern half of the CONUS being colder than normal, but stronger signal seems to be in the upper midwest and pacific northwest.

Also see a strong signal of above normal temps around the 4 corners in the west (as I expected).

I also think we go dry or near normal precip almost across the board, except maybe OH valley / midwest. 

And the part you're most interested in...

Mid-atlantic Snowfall

First, let's talk storm tracks.

I see primarily cutters and clippers, some suppressed tracks, and I expect more than a few miller Bs to blow up off the EC and drop the hammer on NYC & north. One of those may very well be historic. (NYC-Boston corridor - watch out, make sure your roofs are in good shape!)

As for this sub, I think slightly below average snowfall is the best we're gonna do. Unfortunately, there's a fair chance that we'll get a dud like 2011-12. 

I'm leaning towards a combo of 99-00/00-01 and maybe even a 85-86, which would be decent for us.

Snow Predictions: 

- DCA: 7-12"
- IAD: 9-15"
- BWI: 10-16"

Temp Predictions:

- Nov: +2
- Dec: -2
- Jan: -1
- Feb: +3
- Mar: 0

[Eskimo Joe]

Given the past 3 winters, this would be solid. Hope you're too warm for February!

[Terpeast]

39 minutes ago, Eskimo Joe said:

Given the past 3 winters, this would be solid. Hope you're too warm for February!

Yeah, the weenie in me hopes I'm wrong about Feb. Only thing holding me back from bigger snowfall #s is 2011-12 being eerily similar

[WEATHER53]

I’m 0 to -1 on temps and bit more hopeful snow 14-18. Same basic idea 

[IUsedToHateCold]

Great write-up, I agree with just about everything (perhaps a warmer anomaly for November and January). I do think there will be 2-3 weeks in late Dec-early Jan that could be productive for us in the snowfall department. It's a roll of the dice. 

[WEATHER53]

In talking with who I consult, this really looks like outcome analogs versus Nina anticipated outcomes. 
That itself is exciting and frankly after todays talks Im eager for this winter. 
 

[WinterWxLuvr]

Thanks for

the time put into this. I did see the word clippers in your write up. Clippers have been extinct since about 2015 I believe lol

[Terpeast]

1 hour ago, WinterWxLuvr said:

Thanks for

the time put into this. I did see the word clippers in your write up. Clippers have been extinct since about 2015 I believe lol

This article points out a few examples of strong clippers with bigger than usual snowfalls in MN. 

worth noting most of the examples cited happened during nina years. Also that dec 28-29, 2000 was a precursor to the dec 30 blizzard that hit NYC. 

I see those kinds of systems happening again this winter. Doesn’t mean we (mid atlantic) will get anything out of those, so you do have a valid point.

https://www.dnr.state.mn.us/climate/journal/january-14-2022-super-clipper.html

 

[40/70 Benchmark]

Good job.

I like your analogs, but I'm not sure why you chose to disregard low ACE based on an increase in activity. We are still definitely low ACE.

I would also be careful about implying that this will be a bonafide moderate la nina because its struggling to even get there in terms of ONI.

I think Hunga Tonga is a wild card in terms of precip that needs to be considered.

[Terpeast]

2 hours ago, 40/70 Benchmark said:

Good job.

I like your analogs, but I'm not sure why you chose to disregard low ACE based on an increase in activity. We are still definitely low ACE.

I would also be careful about implying that this will be a bonafide moderate la nina because its struggling to even get there in terms of ONI.

I think Hunga Tonga is a wild card in terms of precip that needs to be considered.

Thanks, and you’re right about the low ACE. When I wrote this, the atlantic was pretty active so I figured that it would catch up… and then it died down after Ian. So I might go down another rabbit hole revisiting low ACE years to see if there any similarities, or if it could possibly throw my outlook off. 

[40/70 Benchmark]

1 hour ago, Terpeast said:

Thanks, and you’re right about the low ACE. When I wrote this, the atlantic was pretty active so I figured that it would catch up… and then it died down after Ian. So I might go down another rabbit hole revisiting low ACE years to see if there any similarities, or if it could possibly throw my outlook off. 

It's worth checking before you go through any editing trouble because believe it or not, there is actually symmetry between my concurrent analogs, and low ACE, high solar years.

[Daniel Boone]

On 10/5/2022 at 11:58 AM, Terpeast said:

Okay here goes, back in the game. Dusting off my research skills and we'll see how it goes. 

Outlook is based on 2 things:

- Backward looking indicators using historical analogs for La Nina, +QBO, -PDO, -IOD, and high solar activity
- Forward looking indicators such as atlantic SSTs and wildcards like high stratosphere vapor content (Hunga Tonga)

My best analogs are:

- 2000-01 (no surprise)
- 2011-12
- 1985-86

I've also looked at 2017-18 and 2008-09, but didn't put a whole lot of weight on them. 

I was going to look at hurricane activity and years of low ACE, but I threw that out the window since things have been picking up in the atlantic.

My DFJ maps using my analogs:

 

 

Commentary:

I expect La Nina to maintain moderate through January and then weaken into March, when everything also trends neutral. This outlook also banks on a milder than normal November, then as the -IOD trends toward neutral, the winter will become milder (especially February) as we go on after a cold start.

Just based on these analogs alone, this is not supposed to be a productive winter. 

BUT... based on recent trends in the stratosphere and model forecasts, there's a chance that we may get a little bit of help from a negative -NAO if and whenever the pacific cooperates.

The opposing factor is high solar activity and +QBO, but we can have a decent winter despite those (e.g. 13-14 & 14-15). 

I don't see the entire eastern half of the CONUS being colder than normal, but stronger signal seems to be in the upper midwest and pacific northwest.

Also see a strong signal of above normal temps around the 4 corners in the west (as I expected).

I also think we go dry or near normal precip almost across the board, except maybe OH valley / midwest. 

And the part you're most interested in...

Mid-atlantic Snowfall

First, let's talk storm tracks.

I see primarily cutters and clippers, some suppressed tracks, and I expect more than a few miller Bs to blow up off the EC and drop the hammer on NYC & north. One of those may very well be historic. (NYC-Boston corridor - watch out, make sure your roofs are in good shape!)

As for this sub, I think slightly below average snowfall is the best we're gonna do. Unfortunately, there's a fair chance that we'll get a dud like 2011-12. 

I'm leaning towards a combo of 99-00/00-01 and maybe even a 85-86, which would be decent for us.

Snow Predictions: 

- DCA: 7-12"
- IAD: 9-15"
- BWI: 10-16"

Temp Predictions:

- Nov: +2
- Dec: -2
- Jan: -1
- Feb: +3
- Mar: 0

Great job ! I like 85-86. Been pondering that one for awhile. 

[Terpeast]

49 minutes ago, Daniel Boone said:

Great job ! I like 85-86. Been pondering that one for awhile. 

What’s interesting about that winter is that it was backloaded. Most of its snow came in Feb. Overall it was on the cold side though. 

[Daniel Boone]

41 minutes ago, Terpeast said:

What’s interesting about that winter is that it was backloaded. Most of its snow came in Feb. Overall it was on the cold side though. 

Yes. We were fortunate down here as January featured a Total of 20".  3 of which were around 6" each. Feb. 18" Total . One being 13.5" on Valentine's day. Another oddity, December, although rather mild produced a White Christmas with a couple inches. 

[Terpeast]

Read my own outlook, and don’t see much reason to change anything for now. 

November is off to a very warm start, and next week’s cold weather will reduce the magnitude of warm anomalies. Then the pattern I believe will relax a bit after the cold shot. Pretty confident we’ll finish the month at +2 if not much higher. 

Still expecting another flip to cold after Thanksgiving. 

[mattie g]

11 hours ago, Terpeast said:

Read my own outlook, and don’t see much reason to change anything for now. 

November is off to a very warm start, and next week’s cold weather will reduce the magnitude of warm anomalies. Then the pattern I believe will relax a bit after the cold shot. Pretty confident we’ll finish the month at +2 if not much higher. 

Still expecting another flip to cold after Thanksgiving. 

Thanks for keeping up with this. It's always good to have a met follow up on their own takes and address whether any adjustments need to be made.

I'll take a flip to cold after Thanksgiving. General pattern progression would put much/most of December in play, then we let the chips fall.

[Terpeast]

November turned out to be +3 and we’re looking at a strong -nao and colder temps in December, so things are on track so far. 

I would love to get a big snow in December but I’m not seeing deep cold with the aleutian ridge / -pna. If we do get a storm mid-Dec or earlier, the H5 maps over the pacific look like it might not be cold enough for an all snow event. 

I think this winter will be full of surprises, though. 

[Jebman]

On 12/1/2022 at 6:31 PM, Terpeast said:

November turned out to be +3 and we’re looking at a strong -nao and colder temps in December, so things are on track so far. 

I would love to get a big snow in December but I’m not seeing deep cold with the aleutian ridge / -pna. If we do get a storm mid-Dec or earlier, the H5 maps over the pacific look like it might not be cold enough for an all snow event. 

I think this winter will be full of surprises, though. 

It will. You guys are gonna get far more snow than you ever imagined this winter in the DC Metropolitan Region.

 

[Terpeast]

Dropping in real quick...

So far December temps are near normal for the MA. With the arctic front though, it's a pretty safe bet to finish the month with slightly below normal temps. Don't know if we'll get -2 like I predicted on the month, but we may get pretty close to that. 

As far as snowfall, I think it's just been bad luck that we didn't get any for the metros while far interior N&W got a little this morning. In a stubborn La Nina, you need a perfect PNA+ ridge in December to get any snowfall. Despite the "epic" pattern, that was the missing piece.

Although I'm punting into the second week of January, I don't buy into the doom and gloom that if we don't get any snow in December during a nina, then the rest of the winter is DOA. 

I think the nina is on its way out, and the atmosphere is already starting to decouple from the base nina state. We may actually end up with a backloaded winter. This is starting to look like a slightly warmer version of 1985-86 if my outlook continues on track. 

[Terpeast]

The stats

Here are the temp anomaly stats at IAD in F:

Dec: -0.8
Jan: +8.4 (!!)
Feb: +8.2
Mar: +2.3 (through 17th)

Well, what can I say? After correctly predicting a warm Nov and cool Dec, my outlook completely fell apart as soon as the post-Dec cutter arctic cold left the building. Although it didn't feel like an all-out torch, we had constant 50s through the whole winter, including prime climo for snowfall. We hardly got below freezing most nights. 

 

What the hell happened?

Here are the NCEI anomaly maps for DJF. 

 

 

It's one thing to have a winter with slightly above normal temps (+1 to +3), but THIS is a whole another level. No wonder we got no real measurable snow.

Remember, our climo 850mb temps are around -4 to -5 C in Jan-Feb, and even if we were +2 or +3, we would still have gotten snow albeit less than climo. Or a big storm with 0 to -1 850s hugging the fall line putting us above climo.

But this was what we were up against (credit to CAPE):

Highly anomalous aleutian high that rarely pushed east or poleward, helped dump cold air from Siberia (which had record cold) into the West. 

What caused this anomalous aleutian high? 

- Expanded hadley cell (credit to Chuck and PSU)
- A moderate but very well coupled La Nina (with a modoki-ish look = terrible for us)
- Extremely and deeply negative PDO (record values leading into the winter)

So it was no surprise that we had a persistent SER/WAR throughout the whole winter. Even when we had a PNA ridge "trying" to develop over the west, a constant stream of troughs thanks to that aleutian ridge kept pushing the PNA ridge over east, suppressing any preceding wave, then pushing the boundary north of us, and allowing any succeeding storm to cut.

I'm sure the warm Atlantic waters did not help us either, but I think that has more of a downstream effect - worth noting that Europe had a record warm winter as well. Could be an effect of the warm ATL SSTs.

Even a SSWE could not save us. It did for NE, but the W trough / Aleutian ridge successfully ran the clock out on us.

 

Okay, so where do we go from here?

I think the lesson learned here is to not rely too strongly on analogs from the past, earlier than 1990 or so. More weight should be on analogs in the past 10-15 years, even though the sample size is so tiny.

My best analog was 1985-86. But that winter was much MUCH colder than this one. It turned out to be a disastrous mismatch, and a failure on my outlook. A better match would have been 2011-12, which was on my analog list. But my personal bias prevented me from putting more weight on it as I should have. 

As it stands now, this winter is in its own league with EXTREME warm anomalies with no comparison to any winter of the past. It is now a new analog to base future winter outlooks next time we have a La Nina coupled with +QBO.

 

So... is it ever going to snow again?

Yes. 100%. 

But will we snap back to climo again? 

I agree with PSU that no, we won't. I believe our new normal is 60-70% of previous climo. Meaning ~14" for IAD, or ~10" for DCA should be the benchmark of what to expect in winters going forward given the warmer climate.

However, that doesn't mean we won't get a 2' blizzard ever again. 

Remember our climo 850s, even if we adjust for the warmer climate, are still below 0 for a solid 2 months. 

If we get an El Nino, -QBO, a sustained +PNA ridge, and an active STJ, we just need a good wave to traverse the south without overamplifying too soon. Then we get hit even with the 0 line straddling the I-95 corridor. 

And all we need is one good hit to reach climo or above. 

I don't think we've reached the tipping point where 850mb temps cannot be 0 or below for our area when we get a wave to approach us. The 3-4 bomb cyclones that struck the immediate MA coast in the last several years is proof of that, in my mind.

Maybe someday we reach that tipping point and the only place it snows is in the mountains above 2k ft. But I don't think we've reached that point yet.

That said, the smaller events we used to get from clippers or from front-end dumps with primary lows to the NW, are fast dwindling and I don't think we get those back.

The next El Nino will be the real test of this, though. 

Could it bring back big winters like 02-03, 09-10, 13-15, or will it just flood the NH with more and more warmth and set a new climate baseline? 

 

 

 

[clskinsfan]

Great post. And I agree with a lot of it. The bigger question for me is with the current climate are we going to be dealing with Nina's going forward. We have had 4 Nino's since 2005. 4 Nino's in 18 years. If Nina is going to predominate base state going forward we are screwed regardless. 

[Terpeast]

16 minutes ago, clskinsfan said:

Great post. And I agree with a lot of it. The bigger question for me is with the current climate are we going to be dealing with Nina's going forward. We have had 4 Nino's since 2005. 4 Nino's in 18 years. If Nina is going to predominate base state going forward we are screwed regardless. 

Yeah, it’s quite possible that ninas will become more commonplace in this warmer climate. And I’ve alluded to that possibility, too. My biggest fear is that if mid-lat SSTs warm faster than tropical SSTs, will we find ourselves in a permanent la nina state?

[WEATHER53]

Whatever mechanism prevents cold high pressure from setting up from Montreal to NY state was the culprit

We has good frontal passages with record setting day  in December and bout 3 more windy, very cold shots but in Every case they were 1 day affairs as the high did not drift off the New England coast but rather plunged rapidly toward Bermuda. 
90% of the lows therefore were cutters even though models did not recognize the pattern half the time 

[TheClimateChanger]

On 3/18/2023 at 2:20 PM, Terpeast said:

Yeah, it’s quite possible that ninas will become more commonplace in this warmer climate. And I’ve alluded to that possibility, too. My biggest fear is that if mid-lat SSTs warm faster than tropical SSTs, will we find ourselves in a permanent la nina state?

https://www.washington.edu/news/2022/10/03/study-suggests-la-nina-winters-could-keep-on-coming/

[WEATHER53]

Terp- Remember how the high would set up to our north and slowly move e-ese then one or two clippers  would undercut that cold dome  and we would stay cold for a week and longer. Cold air in place and wait for the “A”

Happens never right now. 
Truth  for me is that even In this modern time, DC gets big snow   and or cold once every 6/7 years. 
Bad lately though. 

[Daniel Boone]

7 hours ago, WEATHER53 said:

Whatever mechanism prevents cold high pressure from setting up from Montreal to NY state was the culprit

We has good frontal passages with record setting day  in December and bout 3 more windy, very cold shots but in Every case they were 1 day affairs as the high did not drift off the New England coast but rather plunged rapidly toward Bermuda. 
90% of the lows therefore were cutters even though models did not recognize the pattern half the time 

The missing 50-50 early on looked like the culprit. However, even with it the HP still didn't do as you'd want. 

[Daniel Boone]

On 3/18/2023 at 1:30 PM, Terpeast said:

The stats

Here are the temp anomaly stats at IAD in F:

Dec: -0.8
Jan: +8.4 (!!)
Feb: +8.2
Mar: +2.3 (through 17th)

Well, what can I say? After correctly predicting a warm Nov and cool Dec, my outlook completely fell apart as soon as the post-Dec cutter arctic cold left the building. Although it didn't feel like an all-out torch, we had constant 50s through the whole winter, including prime climo for snowfall. We hardly got below freezing most nights. 

 

What the hell happened?

Here are the NCEI anomaly maps for DJF. 

 

 

It's one thing to have a winter with slightly above normal temps (+1 to +3), but THIS is a whole another level. No wonder we got no real measurable snow.

Remember, our climo 850mb temps are around -4 to -5 C in Jan-Feb, and even if we were +2 or +3, we would still have gotten snow albeit less than climo. Or a big storm with 0 to -1 850s hugging the fall line putting us above climo.

But this was what we were up against (credit to CAPE):

Highly anomalous aleutian high that rarely pushed east or poleward, helped dump cold air from Siberia (which had record cold) into the West. 

What caused this anomalous aleutian high? 

- Expanded hadley cell (credit to Chuck and PSU)
- A moderate but very well coupled La Nina (with a modoki-ish look = terrible for us)
- Extremely and deeply negative PDO (record values leading into the winter)

So it was no surprise that we had a persistent SER/WAR throughout the whole winter. Even when we had a PNA ridge "trying" to develop over the west, a constant stream of troughs thanks to that aleutian ridge kept pushing the PNA ridge over east, suppressing any preceding wave, then pushing the boundary north of us, and allowing any succeeding storm to cut.

I'm sure the warm Atlantic waters did not help us either, but I think that has more of a downstream effect - worth noting that Europe had a record warm winter as well. Could be an effect of the warm ATL SSTs.

Even a SSWE could not save us. It did for NE, but the W trough / Aleutian ridge successfully ran the clock out on us.

 

Okay, so where do we go from here?

I think the lesson learned here is to not rely too strongly on analogs from the past, earlier than 1990 or so. More weight should be on analogs in the past 10-15 years, even though the sample size is so tiny.

My best analog was 1985-86. But that winter was much MUCH colder than this one. It turned out to be a disastrous mismatch, and a failure on my outlook. A better match would have been 2011-12, which was on my analog list. But my personal bias prevented me from putting more weight on it as I should have. 

As it stands now, this winter is in its own league with EXTREME warm anomalies with no comparison to any winter of the past. It is now a new analog to base future winter outlooks next time we have a La Nina coupled with +QBO.

 

So... is it ever going to snow again?

Yes. 100%. 

But will we snap back to climo again? 

I agree with PSU that no, we won't. I believe our new normal is 60-70% of previous climo. Meaning ~14" for IAD, or ~10" for DCA should be the benchmark of what to expect in winters going forward given the warmer climate.

However, that doesn't mean we won't get a 2' blizzard ever again. 

Remember our climo 850s, even if we adjust for the warmer climate, are still below 0 for a solid 2 months. 

If we get an El Nino, -QBO, a sustained +PNA ridge, and an active STJ, we just need a good wave to traverse the south without overamplifying too soon. Then we get hit even with the 0 line straddling the I-95 corridor. 

And all we need is one good hit to reach climo or above. 

I don't think we've reached the tipping point where 850mb temps cannot be 0 or below for our area when we get a wave to approach us. The 3-4 bomb cyclones that struck the immediate MA coast in the last several years is proof of that, in my mind.

Maybe someday we reach that tipping point and the only place it snows is in the mountains above 2k ft. But I don't think we've reached that point yet.

That said, the smaller events we used to get from clippers or from front-end dumps with primary lows to the NW, are fast dwindling and I don't think we get those back.

The next El Nino will be the real test of this, though. 

Could it bring back big winters like 02-03, 09-10, 13-15, or will it just flood the NH with more and more warmth and set a new climate baseline? 

 

 

 

Anomalies Map looks alot like Jan. 1950.

[Terpeast]

36 minutes ago, WEATHER53 said:

Terp- Remember how the high would set up to our north and slowly move e-ese then one or two clippers  would undercut that cold dome  and we would stay cold for a week and longer. Cold air in place and wait for the “A”

Happens never right now. 
Truth  for me is that even In this modern time, DC gets big snow   and or cold once every 6/7 years. 
Bad lately though. 

Because the high usually falls on the east side of a ridge (and/or west side of a trough), we need the pna ridge to sustain itself like a standing wave to keep the high from moving out too quickly. 

But the pna ridge kept getting shoved over by that wavetrain crashing into the west, allowing the cold dome to spill off the coast clearing the way for incoming storms to cut. 

We can trace the culprit to the Aleutian ridge supported by the -pdo in the last 7 years, five of which were ninas and only one a nino that couldn’t overcome the pac state. 

I think it’s all pretty clear to me “what” the culprit was. Now the “why” behind that culprit - that’s where the debate is. 

[Amped]

If I told you that we would get near record setting Greenland blocks in December and March would anyone of the long range forecasters have predicted we'd get no snow from either?

[Terpeast]

8 hours ago, Amped said:

If I told you that we would get near record setting Greenland blocks in December and March would anyone of the long range forecasters have predicted we'd get no snow from either?

If you told me this last November, I would have been confident of one hit. Still wouldn’t have gone above climo snowfall because those blocks weren’t going to happen in Jan or Feb