Winter 2023-4 Post-Mortem Thread

[NorthHillsWx]

With winter on the ropes and the main threads descending into climate change discussions, finger pointing and long range Icon hope, let’s discuss how this winter failed so miserably. Was it poor model performance, over-hyping ENSO, bad luck, climate change, reliance on analogs or some combination of everything? Let’s dive in and leave the main board for actual forecast discussion and the sanitarium for, well, the folks who need it. What better time to discuss a winter failure than on February 10 while it feels like 80 outside and our “best look in years” collapsed in 18 hours of disastrous model runs!

[wncsnow]

I think the MJO is playing a bigger role than some like to think. It has been in general unfavorable phases this winter. 

[BooneWX]

I want to give a shout out to @BuffaloWeather. While the winter in the south sucked, your livestreams during lake effect have not. Hopefully you’ve got one more event left at least!

[BuffaloWeather]

4 hours ago, BooneWX said:

I want to give a shout out to @BuffaloWeather. While the winter in the south sucked, your livestreams during lake effect have not. Hopefully you’ve got one more event left at least!

Thank you! Appreciate it! 

[NorthHillsWx]

I think the biggest issue is a simple one, we haven’t been able to lock in a favorable HP at all. The NS keeps obliterating every strong high that tries to establish itself regardless of blocking. Believe it or not, we don’t need pure arctic air to snow or get wintry wx east of the mountains. CAD has become a thing of the past, and those storms are our most frequent. Yes we are all searching for the miller A unicorn without thermal issues, but the vast majority of our wintry weather historically has come from miller B mixed bags and overrunning events. Pure Arctic air looks good on paper and long range models but it usually leads to suppression or transient cold shots without a New England high established 

[NorthHillsWx]

As for global warming, sea surface temps are smashing records every year in the Atlantic. Blame it on what you want but that’s the truth. I think that impacts 2 things:

1) SER becomes semi-permanent 

2) Thermals with coastal storms are frequently messed up more so than past analogs for similar tracks would indicate 

Take this weeks storm in New England. It it literally passing over the 40/70 benchmark in their peak climo, and thermals in NYC and most coastal areas are going to struggle. Perfect track New England systems shouldn’t struggle that much, though thankfully for them, the system may be dynamic enough to overcome poor lower levels 

[eyewall]

8 hours ago, NorthHillsWx said:

As for global warming, sea surface temps are smashing records every year in the Atlantic. Blame it on what you want but that’s the truth. I think that impacts 2 things:

1) SER becomes semi-permanent 

2) Thermals with coastal storms are frequently messed up more so than past analogs for similar tracks would indicate 

Take this weeks storm in New England. It it literally passing over the 40/70 benchmark in their peak climo, and thermals in NYC and most coastal areas are going to struggle. Perfect track New England systems shouldn’t struggle that much, though thankfully for them, the system may be dynamic enough to overcome poor lower levels 

This really has to be taken into account despite not wanting to talk about the elephant in the room around here.

[wncsnow]

9 hours ago, NorthHillsWx said:

As for global warming, sea surface temps are smashing records every year in the Atlantic. Blame it on what you want but that’s the truth. I think that impacts 2 things:

1) SER becomes semi-permanent 

2) Thermals with coastal storms are frequently messed up more so than past analogs for similar tracks would indicate 

Take this weeks storm in New England. It it literally passing over the 40/70 benchmark in their peak climo, and thermals in NYC and most coastal areas are going to struggle. Perfect track New England systems shouldn’t struggle that much, though thankfully for them, the system may be dynamic enough to overcome poor lower levels 

The SER has ruined any small chance of snow this winter. Even with this current system. 

[UnionCountyNCWX]

10 hours ago, NorthHillsWx said:

I think the biggest issue is a simple one, we haven’t been able to lock in a favorable HP at all. The NS keeps obliterating every strong high that tries to establish itself regardless of blocking. Believe it or not, we don’t need pure arctic air to snow or get wintry wx east of the mountains. CAD has become a thing of the past, and those storms are our most frequent. Yes we are all searching for the miller A unicorn without thermal issues, but the vast majority of our wintry weather historically has come from miller B mixed bags and overrunning events. Pure Arctic air looks good on paper and long range models but it usually leads to suppression or transient cold shots without a New England high established 

Maybe that's the key though, to be looking for unicorns. Every time there's talk over the past couple of years (may go back further but I've noticed this since I've moved from Boone to Monroe) about a true "pattern change" in the winter it NEVER happens. At the MOST, we've had a couple days where it is cooler, or even maybe a couple of days of cold, but a true pattern change has not happened, as much as it's advertised. Unless a true Nino happens that actually acts like one, I don't think we can actually score anymore in a "good" setup, we HAVE to count on luck.

[NorthHillsWx]

12 minutes ago, UnionCountyNCWX said:

Maybe that's the key though, to be looking for unicorns. Every time there's talk over the past couple of years (may go back further but I've noticed this since I've moved from Boone to Monroe) about a true "pattern change" in the winter it NEVER happens. At the MOST, we've had a couple days where it is cooler, or even maybe a couple of days of cold, but a true pattern change has not happened, as much as it's advertised. Unless a true Nino happens that actually acts like one, I don't think we can actually score anymore in a "good" setup, we HAVE to count on luck.

While I agree, that period around last Christmas qualifies as a true pattern change. We just got unlucky there, but a week mostly below freezing is impressive for anywhere in the Carolina’s. This season didn’t feature anything I would consider to be a pattern change. The “cold blast” in January was essentially a frontal passage that flipped right back to AN, there was transient cold nothing locked in.

You bring up a good point though: what is a pattern change? What are the minimum qualifications to say the pattern has changed or would you consider this January just a cold snap within the same pattern we were stuck in? I lean the latter.

For me, a pattern change needs these qualifications:

1) altered H5 orientation across country 

2) retention or addition of SER

3) either strengthening or weakening of STJ and/or NS

You can throw in blocking, the state of the PAC, MJO, or many other indices but imo those 3 variables dictate sensible weather here and must all be altered to constitute a pattern “change” vs a blip within a set pattern. I don’t know if you can throw a time qualifier in there as well, such as H5 state must last at least 72 hours or something along those lines, but I could hear that argument as well

[BooneWX]

Another layer to this climate change conversation:

 

We as a region are very dependent on proper cold from source regions. Snowpack to our north has been absolutely anemic this year and in years past. Arctic air doesn’t have that same punch that it used to because of it imo. As climate change warms the northern latitudes, it’s just going to get increasingly more challenging for cold air to not moderate as it moves south. 

[NorthHillsWx]

1 hour ago, BooneWX said:

Another layer to this climate change conversation:

 

We as a region are very dependent on proper cold from source regions. Snowpack to our north has been absolutely anemic this year and in years past. Arctic air doesn’t have that same punch that it used to because of it imo. As climate change warms the northern latitudes, it’s just going to get increasingly more challenging for cold air to not moderate as it moves south. 

Yes and no. Northern areas should still be cold enough for snow and long lasting snow. Last year the upper NW and dakotas set records. This year it’s been anemic there bc it’s been so dry. The lack of New England snow to me is more pattern related than it simply being too warm. Check the cold outbreak west of the mountains this year. That was able to maintain itself in the Deep South despite little to no snow cover in the upper MW. Now there are times where we 100% benefit from existing snowpack to our north, say down to Pennsylvania, especially for borderline in-situ damming events. But I don’t think the recent lack of source region (NE away from coastline and Canada) snowpack is totally influenced by climate change 

[Brick Tamland]

All the local TV mets here called for above average snow here. Huge bust. Looks like it's not even going to snow. Couldn't even get a system that was close to snow. Everyone bet on the Nino to bring us more snow. Something has definitely changed because the things that used to be good for us in the past to get snow here don't seem to work as well.

[GaWx]

8 hours ago, BooneWX said:

Another layer to this climate change conversation:

 

We as a region are very dependent on proper cold from source regions. Snowpack to our north has been absolutely anemic this year and in years past. Arctic air doesn’t have that same punch that it used to because of it imo. As climate change warms the northern latitudes, it’s just going to get increasingly more challenging for cold air to not moderate as it moves south. 

Look how warm the Arctic has been. What’s also interesting is that the Arctic’s coldest day in the means isn’t for another 13 days, Feb 25. Feb actually is slightly colder than Jan:

[NorthHillsWx]

41 minutes ago, GaWx said:

Look how warm the Arctic has been. What’s also interesting is that the Arctic’s coldest day in the means isn’t for another 13 days, Feb 25. Feb actually is slightly colder than Jan:

That is absurd. 

[NorthHillsWx]

One other symptom I believe we’re seeing of a warm Atlantic has played out in the MA and NE over the last week. They got a perfect track coastal storm and, other than a few bands where rates overcame BL temps, most areas struggled to accumulate. Boston was mostly rain from a storm traveling south of the 40/70 benchmark in mid February! You cannot tell me that the sst anomaly along the east coast wasn’t at least partly to blame for the outcome of that system in areas where the flow came off the water. Now for the flip side- this clipper that just went through. Without any coastal influences and no coastal flow, it was able to produce a stripe of snow from 8-14” from the Midwest to the coast. In fact, even areas outside the band were able to accumulate efficiently. I know the DC area got screwed but that was mostly due to the storm track and lack of precip in that area. 
 

My point is this: both of those were borderline BL temp setups and one was far more efficient at producing snow than the other. Down here, EVERY event just about is borderline, and given the same setup as they experienced, that 2-3 degree coastal influence due to excessively warm sst can be the difference between what, given normal sst, would be a winter storm vs a rainstorm. Just pretty wild to see in many regards a clipper outperform a juiced up coastal in prime climo in NE

[eyewall]

Here is more on the super warm Atlantic:

[WinstonSalemArlington]

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