NittanyWx

1 hour ago, WX-PA said:

What's IOD?...seems like that's another way for it not to snow here?..lol

The Indian Ocean Dipole.  Coupled atmospheric/ocean temperature pattern, measured by the difference between ocean temps off the coast of NE Africa and Sumatra.

Indian Ocean climate influences (bom.gov.au)

1 hour ago, uofmiami said:

 

He's making a fair point about the seasonal IOD collapse and subsequent weakening of the standing wave signal in the IO.  Not sure that's necessarily the way out on it's own like he's indicating here, but the path analysis to source region shift makes sense conceptually.

16 hours ago, brooklynwx99 said:

the temp anomalies in Canada are a bit overrated IMO. look at Feb 2022. Canada was an icebox, but it didn't matter because the 500mb pattern sucked and the mean storm track was to the west. I would much rather have an above normal Canada if the 500mb pattern leads to coastal storms

 

Sure, in certain instances it doesn't work out with a colder Canadian airmass nearby to tap into for a plethora of reasons.   We have certainly seen cases where promising Canadian airmasses and cold air supply are accompanied by jet suppression. 

However, historically, patterns with a normal to cooler than normal Canadian airmass providing available air to tap into are significantly better performing for the local area than alternative when it comes to snowfall.  At least I've certainly found that to be the case in my career.   

You're talking about statistical odds.  As I discussed yesterday, no one is saying it cannot snow ever in this pattern, I'm certainly not and I do like the 500mb pattern from a 1000 foot view.  But it's not unreasonable to say it is statistically less likely than the alternative.  

Just now, EastonSN+ said:

If I am not mistaken, we obviously need a track to the south/east of us (i.e. overrunning snow to rain is unlikely) as well as decent intensification and rates. 

Missing Canadian HP from your equation.

6 minutes ago, ORH_wxman said:

 

I don't think I ever met a skilled forecaster who said they incorporate a lot of persistence into their forecasts. It's one thing to sort of hedge toward climo in many instances due to familiarity with patterns and how they affect local sensible wx, but that is definitely not the same as a mindless drone "persistence" forecast. The irony in here over the persistence argument is that New England winters typically feature decent snow, so in this case, you can't even really claim persistence is hedging toward climo for the crowd in here that keeps saying it's not going to snow.

Persistence forecasting for persistence sake is normally not a smart way to go about things.  However, in certain patterns in certain years you can meteorologically have a good reason for going with it.  That said, it depends on the meteorological variables on the board at a given time.

I think there's been several years where if you took the persistence view on an extended/monthly basis it worked significantly better than trying to force a pattern change for X reason.  I personally need strong evidence to copy in a persistence view, but I've certainly had bimonthly periods where I felt the pattern was just stuck, I had no real reason to believe it would change in any meaningful way for any appreciable length of time and went with it on a longer range basis.  Yeah, there's some inherent variability in there for small windows but the big picture monthly degree day view made it somewhat negligible.

For the record, I'm not taking the persistence view today.

Just now, brooklynwx99 said:

this pattern is about as far from last year's at it can possibly be. persistence doesn't really make any sense here

I also agree.

6 minutes ago, ORH_wxman said:

The old saying is persistence fails when the stakes are the highest. Besides, this current pattern doesn't look anything like last year so the only "persistence" is the sensible wx of little to no snow and AN temps. There's no reason to actually stick with persistence if evidence is starting to mount that it's coming to an end.

I don't disagree here, but persistence is a view and sometimes it rewards a forecaster who has a healthy dose of skepticism.   It works until it doesnt.  

41 minutes ago, Typhoon Tip said:

If your really want some cognitive dissonance ...

   'time is relative'

  hahahaha

The timing is literally half of the forecast verification, but to some it is a fungible concept 

22 minutes ago, binbisso said:

Yeah I don't get it. By January 1st were starting to get to peak climo. Who wants 15° for a high temperature and 0 for a low? We don't need that. We need a favorable 500 mb Pattern with storm sliding on  south of us, which is exactly What guidance is showing. Otherwise it's congrats Richmond.

There's a large temperature spread between this December anomaly and the number's you're talking about.   However, historically we do better when there's a source airmass in W Canada.

I'm pretty clear in that I think the PNA is 'favorable' for a stormier solution, source is not favorable for a decent cold air supply and that leaves us with chances for snow, but less room for error.

47 minutes ago, 40/70 Benchmark said:

I completely understand skepticism in the sense that long range guidance is prone to large error, so set expectations accordingly. But it needs to stop short of criticizing anyone who dares to venture towards giving a good faith effort, and anyone who sees avenues towards more wintery outcomes because it fosters a close minded approach. That is the antithesis of the type of approach that relatively poor skill at extended lead times should foster, which is an open-mind thought process. Its a weather forum...we discuss long range guidance, even it looks like it may offer wintry opportunities.

That type of mindset is why we have a brigade of 5 PPD members tossing weenies at anyone who dares to mention that forbidden four letter word...sno#. I don't believe you do or endorse that, but your post inhibits efforts to reduce that within this context IMO.

I agree with this, but I also think people need to stop being so sensitive when it comes to pushback on that snow idea.  If someone who's done this for a long time comes out and says 'I think that's wrong and a bad idea', it's not shutting down debate.  It's literally the debate process.  

If you've got a view, take it.  If someone pushes back on your view that's not shutting down debate.  I'm sorry, but you're going to get challenged if you're going to make a forecast.  Need to accept that.  Especially if you continually have the same view and it blows up in your face.  

What I don't accept however, is selective verification.  Far too many people try to convince people they were right after the fact or come with 'well I was wrong on timing and right on idea'...guys timing is as important to the forecast as the directional view.

54 minutes ago, bluewave said:

TEB looks like they tied their all-time December high dewpoint of 64°a few hours ago. 

 

 

2015 and 1982...wonder if those years have something in common with this one

6 minutes ago, snowman19 said:

Bingo!!

 

 

 

 

I'd rather have a quote tweet reply from pretty much anyone else other than BAMWX

I think on the surface a reversion to +PNA with some sort of trof in the east is justified view for early Jan.  There is a lack of significant source air to advect however which has been a common theme.

Now if this PNA spike ends up being more GOA focused, perhaps there's an ability to dislodge some colder air.  But in stormy situations with marginal airmasses, relying on a lot to go 'right' to thread the needle.  That's where my head is at right now.  I still see source region issues.

On 12/6/2023 at 2:03 PM, NittanyWx said:

Thinking is for a transient few cooler days around mid month sandwiched around warmer ones.  I still don't see permanent blowtorch, though I do think the post cool period could produce several much above normal days.

 

 

So just to update my thinking here from a few weeks back...we're in our much above normal temp phase post mid-month transient cool shot.

Now we're left with the following:  still no significant source region in Canada, dire snowpack in the mid-con and while we're seeing a PNA spike on most models...it doesn't have much of a source to tap into.  I think we are likely going to see an erosion of the much aboves heading into early January, but I'd be lying if I didn't say I'm not loving what source air there is to work with at this stage and was a little more hopeful to see the EPO  region shaken up instead of the bulk of this PV piece retro'ing back to Siberia.

The EPS has been struggling, significantly at that, with 2mT cold bias so far this winter.  I suspect it's doing so again late 11-15 day.  That said, I am expecting to see the much aboves ease off a bit.  

H5 improvements are likely in early January. Tropical forcing should be more C Pac/E Pac based as well, but lacking available cold air to tap into I don't see much more than a marginally cooler period ushering in the first week of Jan.

7 hours ago, ForestHillWx said:

Without needing to state the obvious, I think @wishcast_hateris commenting as to the extent of AGW on the ever evolving climate, as the responsive posts correctly point out. 

Candidly when discussing the impacts of “climate change” on our weather patterns there is a built-in narrative that the climate is changing due to human activity, and not in response to natural variability. 
 

And now, back to wishcasting for snow…
 

 

There is an inherent disbelief in his post that a clear climatic trend is occurring because we somehow don't know what happened more than 150 years ago.

It was a silly statement and wrong. 

4 hours ago, wishcast_hater said:

I will never understand how we can declare definitive climate change based on 150 years of records when we have no idea of what took place beforehand.


.

Lol what?

I gotta ask, who told you we have 'no idea' of what happened more than 150 years ago?

2 hours ago, bluewave said:

These extreme rainfall events have become the new normal for us since 2003. Many years in NYC have finished above 50.00”. Plus if this comes far enough west for high winds, this has been a repeating theme since 2010.

 

Time Series Summary for NY CITY CENTRAL PARK, NY - Jan through Dec
Click column heading to sort ascending, click again to sort descending.

Rank	Year	Total Precipitation	Missing Count
1	1983	80.56	Rain gauge malfunction so total likely overdone
2	2011	72.81	0
3	1972	67.03	0
4	2018	65.55	0
5	1989	65.11	0
6	2007	61.67	0
7	1975	61.21	0
8	1990	60.92	0
9	2006	59.89	0
10	2021	59.73	0
11	2003	58.42	0
12	1903	58.32	0
13	1889	58.18	0
14	1913	58.00	0
15	1973	57.23	0
16	1984	57.03	0
17	1971	56.77	0
18	1996	56.19	0
19	1927	56.06	0
20	2005	55.97	0
21	2023	55.21	19
22	1977	54.73	0
23	2014	53.79	0
24	2009	53.62	0
25	2008	53.61	0
26	1933	53.53	0
27	1888	53.32	0
28	1919	53.29	0
29	1920	53.20	0
30	2019	53.03	0
31	1937	52.97	0
32	1902	52.77	0
33	1884	52.25	0
34	1979	52.13	0
35	2004	51.93	0
36	1871	51.38	0

It's not unique to NY either.  Single day rainfall records are being broken and an increasing rate over the past 20 years.  It's one of the cleaner climate change signals we have and passes the scientific sniff test.

9 hours ago, Terpeast said:

Same sentiments. 

I really did think that the mjo would go into 7-8-1 because of those 30c ssts east of the dateline. And those warm waters run even deeper than the MC. 

I thought placing more importance on the impacts of MC ssts over the E Dateline ssts was misguided, but maybe I gotta rethink that. Again, I’m no expert on the MJO because we kinda glossed over it in my met studies. So that’s where my knowledge gap is, I guess

The more 'favorable' VP anoms did progress as expected.  I do think the MJO signal was overamped and overhyped as a function of the pair of tropical cyclones and a Kelvin wave, but this was a pretty clean 200mb VP signal.  I don't think this failed in that sense.

46 minutes ago, brooklynwx99 said:

i don't think that's it's needed per se, but it would definitely help set the stage for a very blocky February. I think the jet retraction is the main catalyst for a more favorable Jan pattern and the main blocking spell coincides with the SPV shenanigans heading into Feb

Yeah for Feb sure, was more talking Jan since that's where we kicked the can to at this point.

9 minutes ago, brooklynwx99 said:

if we get a SSW (which is a legit possibility) then it could seriously be hammer time for February. but we will see about that

Just curious why you think it's the strato that's needed?  We've had blocking over the pole and SSW's are mostly viewed as a way to weaken the PV to allow for more blocking.  There's been the -AO, there's been a -NAO...to me this needs to be some sort of wave breaking signature to change things in the Pacific since default state in Nino years like this is +PNA.

PV splits have a loose correlation to cold roughly 24 days after they occur, but that would then be kicking the can more to Feb, no?  If you're looking for Jan help it's gonna need to be some combo of Pac changes in conjunction with dislodging some cooler air.

I think you're on the right track with the idea of jet retraction, since in my mind the way for this to happen is retrograding +PNA which amps into AK and finally dislodges some cooler air and aims it towards NA.

11 minutes ago, brooklynwx99 said:

heights over AK should improve as the jet retracts, thus improving the source region

the difference with the source region is night and day comparing the end of December and the start of Jan, verbatim anyway. you have cross polar flow in Jan showing up there

Yes I agree its a better look synoptically in terms of shutting off the Pac flow and potentially dislodging something colder out of the artic and pushing it towards this side of the pole.  Maybe not hammer cold, but an erosion of the much above.

When we spoke 10 ish days ago, i felt the way to do this was with some sort of PNA retro, amp into AK after jet retraction and the Kara Sea piece allowing for some cold to be able to be tapped.  This is in a way similar to that idea and an important step in this process.  Split flow would increse the odds that pattern would deliver some sort of storm with as you head into that Jan 5-15 window.

Let's see if it rolls forward.  As I said before, I'm in the agnostic camp at that range. 

57 minutes ago, brooklynwx99 said:

not making a direct pattern comparison to Feb 2010 by any means, just saying that Canada doesn't need to be frigid or even near normal for our intents and purposes. their averages are way colder than ours. that doesn't address the lack of cold air here, but it can be colder than average here and way warmer than average there and it works

Couple things...first, you had a midcon snowpack then:

Vs now:

And really my point a couple weeks ago was 'what air are you advecting?' when you went back to a +PNA for that Christmas week.

Not saying it can't snow from a one off, but I am saying this current setup that was shown for the last week of Dec wasn't a modeling error.  It actually looks like a really good forecast. 

So now it's really to me about finding a way to dislodge that extremely +EPO and also weaken that Pac jet extension.  Yeah i don't think climo supports the Pac jet staying extended for long, but I still am of the belief that some source region is needed after the Pac air floods most of NA.

It's possible, but I really do believe if you want a prolonged snowier period in this type of climate you need some Canadian HP and it would help to have some form on a midcon snowpack that is usable in a baseline +PNA scenario.

I'm agnostic at the moment.  Think both things are possible, but I'm not at the probable stage until I see some changes in the AK region.

Just to circle back on the source region/weeklies discussion from last week:

This look from the EC Ens mid 11-15 day now looks a lot like the weeklies from a couple weeks back at H5

Now at the time there was debate about MJO being the precursor to find cold in this pattern.  However, as discussed then, the concern was that there wasn't cold in western Canada to be displaced and a lack of snowcover would modulate a very weak cP airmass in the event of a +PNA.

The 2m temps from the EC Weekly for that period:

So in my view, this strong + EPO forecast and roll forward was pretty well advertised.  And shouldn't come as too much of a surprise given source airmass and seasonal factors tending to support that idea in December strong Nino's.

The models are forecasting the MJO progression in both of these cases.  So the use case of 'I can forecast the anomaly better than the model because I feel the model isn't seeing the true reflecfion of the MJO' actually led to negative forecast skill.  Utilizing the weeklies in this case would've been prudent and understanding the source region wasn't sufficient are and were very important pieces of this puzzle.

1 hour ago, Stormlover74 said:

The scary part is I can't tell if he's doing it for the clicks or if he really believes what he spews. 

He's lost the energy audience because they've been burned by him calling 55 of the past 2 cold shots.

The h5 charts at the end of the EC Ens don't look that much different from what the EC weeklies were showing in that post Christmas time period.

Aleutian low, +EPO, +PNA but no source air.  Flagged it at the time that this wasnt gonna be the cold look people thought it would be, but if that ends up rolling forward it's actually a pretty decent forecast from the weeklies.