December 2021

[Superstorm93]

Certainly nothing to sneeze at. 

 

 

[MJO812]

26 minutes ago, bluewave said:

People making posts discussing the current actual pattern is not trolling. 

So he never trolls ?

I wasn't talking about you

 

[MJO812]

7 minutes ago, Superstorm93 said:

Certainly nothing to sneeze at. 

 

 

Loving the ridge to Alaska

[EasternLI]

Getting EQBO composite vibes from the extended 12z EPS mean today. 

[binbisso]

24 minutes ago, snowman19 said:

You are going to get cutters with a full latitude -PNA trough in the west and a SE ridge. Keep following the wish casters and believe that a huge cold and snowstorm pattern is inbound. It’s hilarious

 What are you looking for a full latitude PNA ridge a West base NAO and a negative EPO  for it to snow here.   It has snowed in worse patterns than what the ensembles are showing Post 12/20. It's a very serviceable pattern and I'd be surprised if it doesn't snow for at least parts of our area during that time frame 

[Brian5671]

35 minutes ago, bluewave said:

People making posts discussing the current actual pattern is not trolling. 

Exactly.   Cant just hype "cold and snow right around the corner" from 11/15 to 3/15 every year.  The current pattern is not great and any changes are still in fantasy land range at this juncture.

We still continue on with the very dry pattern which is a problem too...

[bluewave]

6 minutes ago, MJO812 said:

So he never trolls ?

I wasn't talking about you

 

I just mean that I wouldn’t consider a pattern critique trolling. I have no problem with anyone criticizing a pattern or a weather model. It would be nice if the GEPS is right about the SE Ridge flattening out during the last week of the month. It kind of looks like what we would hope for with a MJO 8 and +AAM.

 

[binbisso]

1 minute ago, Brian5671 said:

Exactly.   Cant just hype "cold and snow right around the corner" from 11/15 to 3/15 every year.  The current pattern is not great and any changes are still in fantasy land range at this juncture.

We still continue on with the very dry pattern which is a problem too...

 I don't think anyone is hyping cold and snow Actually I think it's the opposite.  Obviously this week is lost So nothing to speak about through Friday However the pattern does start to turn favorable after that there's nothing wrong with talking about post 7 day ensembles. 

[brooklynwx99]

1 hour ago, bluewave said:

You have to realize that the discussion we are having is about the pattern leading up to Christmas. Not sure what you mean by changing goalposts.The post Christmas pattern potential has been discussed here at length. The hope has always been that the Pacific can relax enough to flatten out the SE Ridge. Getting a MJO closer to phase 8 with a +AAM could be helpful. So try going back and reading more before you leave a snarky quick post telling us how we are all gloom and doom.

I’m not saying that everyone here is trashing the pattern here. All I was saying is that I think that the general tone of discussion is overly negative for what will be at least a serviceable pattern showing up around Christmas, that’s all

[brooklynwx99]

44 minutes ago, snowman19 said:

You are going to get cutters with a full latitude -PNA trough in the west and a SE ridge. Keep following the wish casters and believe that a huge cold and snowstorm pattern is inbound. It’s hilarious

This is not a cutter pattern. Even the EPS with the most aggressive look with SE ridging, there is significant confluent flow in SE Canada modeled thanks to the anomalous -NAO blocking

Not saying that this is a conducive pattern for large storms whatsoever, but the loading patterns for major snowstorms actually features significant western troughing that was overcome by the -NAO, so a -PNA isn’t a death sentence by any means

[bluewave]

58 minutes ago, brooklynwx99 said:

I’m not saying that everyone here is trashing the pattern here. All I was saying is that I think that the general tone of discussion is overly negative for what will be at least a serviceable pattern showing up around Christmas, that’s all

That’s fine. I guess the tone you are seeing is a result of the pattern through the 20th. Hopefully, we get a window of opportunity late month into early January. Kind of looks like the CFS is trying to show something like this. But the question then becomes how long can it last? The CFS retrogrades the pattern to something less favorable by mid-January . It may take a SSW to get a longer lasting boost from from this MJO progression and +AAM spike. Maybe the next few runs of weeklies will provide some clues.

[jm1220]

We have a chance at something decent if the Aleutian ridge can really pop. If it stays too South based the gradient won’t establish far enough south for us and the SE ridge will dominate. 

[SnowGoose69]

23 minutes ago, brooklynwx99 said:

This is not a cutter pattern. Even the EPS with the most aggressive look with SE ridging, there is significant confluent flow in SE Canada modeled thanks to the anomalous -NAO blocking

Not saying that this is a conducive pattern for large storms whatsoever, but the loading patterns for major snowstorms actually features significant western troughing that was overcome by the -NAO, so a -PNA isn’t a death sentence by any means

 

The average of those ensembles is very much like the first half of February in 1994, except the NAO is negative whereas it was largely positive then.  I think the SE ridging is probably overdone even on the weakest members.  There is always a tendency in -PNA/-NAO pattern for the models to overdo SE ridging somewhat in the longer range.

[EasternLI]

Not sure we would want too much of a theoretical +PNA -EPO -NAO pattern. We'd probably just get the polar vortex sitting on our heads and freeze to death. 

[donsutherland1]

The long-range guidance is looking somewhat more promising. However, through the 20th, readings remain likely to average above normal with any cold shots being transient and modest. During the closing 10 days of the month, a somewhat cooler but not very cold regime could begin to unfold. If a period of sustained below normal temperatures will develop, one might need to wait for the first week in January. Then, we’ll have to see whether such a pattern could be sustained or would wind up breaking down within two weeks or so. We’ll also have to wait to see if the severe cold from Alaska/NW Canada moves into the region or remains largely confined to Canada as it spreads eastward.

For perspective, below are the mean temperatures for NYC for 12/21-25 for the last four runs of the EPS:

12/11 0z: 37.7

12/11 0z: 37.0

12/12 0z: 36.7

12/12 12z: 37.9

That’s not much of a change. It’s also somewhat warmer than normal.

[Rjay]

2 hours ago, MJO812 said:

Snowman19 should get banned for laughing at a meteorologist's post. 

It's the same people trolling every winter

If he starts trolling the Mets he will be gone.  He's fine for now though.  

I have always loved Brooklynwx99's optimism.  I hope he never changes.  

[MJO812]

Impressive for an  ensemble mean this far out 

[MJO812]

34 minutes ago, Rjay said:

If he starts trolling the Mets he will be gone.  He's fine for now though.  

I have always loved Brooklynwx99's optimism.  I hope he never changes.  

He is one of my favorite posters 

[Roger Smith]

With the generally dry pattern 2021 is making slow progress up the table and remains in 10th place ...

here's an update of what amounts are needed to reach 9th, 8th and the rest probably out of reach now. 

 

Rank __ YEAR ___ TOTAL PRECIP 

_ 01 ____ 1983 ____ 80.56"

_ 02 ____ 2011 ____ 72.81"

_ 03 ____ 1972 ____ 67.03"

_ 04 ____ 2018 ____ 65.55"

_ 05 ____ 1989 ____ 65.11"

_ 06 ____ 2007 ____ 61.67" (2021 needs 2.66"to tie)

_ 07 ____ 1975 ____ 61.21" (2021 needs 2.20" to tie)

_ 08 ____ 1990 ____ 60.92" (2021 needs 1.91" to tie)

_ 09 ____ 2006 ____ 59.89" (2021 needs 0.88" to tie)

 

_ 10 ____ 2021 ____ 59.01" (.17" on Dec 11)

 

Looking at current GFS output to the 28th, I could see maybe 1.0 to 1.5 inches of precip so would say there's a good chance of overtaking 9th place 2006 and maybe challenging 7th and 8th place 1975, 1990 near the end. 

Also looks to me like a record daily high may be set on Thursday 16th, 63F (1971) appears to be the current record (some warmer days in 2015 earlier in the week), would say 68-72 F a good bet. There's a weak record for the 19th  (only 58F, the lowest such value in December) that on current guidance won't be broken but if the pattern slows down or moves north it could be. Records for the 17th and 18th are 62F and 63F. After the 20th (60F) there's another spell with records closer to 70F again. These daily records can be seen in my thread over in the climate change forum, pack a lunch. 

Yesterday (Sat 11th) set a daily record of 66 F (the former record was 64 F from 1879). 

[donsutherland1]

Another warmup is poised to unfold starting tomorrow. Parts of the Midwest could see daily and December-record temperatures. Des Moines has a shot at seeing its first ever 70° December day. Some of that warmth will affect the region late in the week before cooler air again returns.

No Arctic blasts appear likely for the foreseeable future. Overall, through December 20th, there will likely be only some relatively short-lived cool shots. Afterward, the AO could go negative, increasing the opportunity for colder outcomes.

In the Midwest, Chicago has yet to receive its first measurable snowfall through December 11. Only four prior years saw their first measurable snowfall on December 11 or later:

1. December 20, 2012
2. December 16, 1965
3. December 14, 2001
4. December 12, 1946

The base case is that the closing 10 days of December could turn cooler, though not necessarily cold. Since 1950, there have been 7 cases where the AO averaged +2.000 or above during the first week in December, as has been the case this year. The mean December 21-31 temperature in New York City was 40.2°. The median temperature was 41.5°. The coldest was 35.3° (1951) and the warmest was 44.0° (1979). In short, this historic experience would suggest that there will be no severe Arctic outbreaks in the East this month. It also suggests that New York City will likely have an average temperature of 40° or above this month.

Following very wet July-September periods, winter (December-February) precipitation has typically been near or below normal. The most recent exception was winter 2018-19.

The ENSO Region 1+2 anomaly was -1.1°C and the Region 3.4 anomaly was -0.9°C for the week centered around December 1. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.87°C and the ENSO Region 3.4 anomaly has averaged -0.92°C. La Niña conditions will likely persist into at least late winter.

The SOI was +12.40 today.

The preliminary Arctic Oscillation (AO) figure was +1.290 today

On December 10 the MJO was in Phase 6 at an amplitude of 2.423 (RMM). The December 9-adjusted amplitude was 2.539 (RMM).

Based on sensitivity analysis applied to the latest guidance, there is an implied 85% probability that New York City will have a warmer than normal December (1991-2020 normal). December will likely finish with a mean temperature near 42.3° (3.2° above normal).

 

[RippleEffect]

2 hours ago, jm1220 said:

We have a chance at something decent if the Aleutian ridge can really pop. If it stays too South based the gradient won’t establish far enough south for us and the SE ridge will dominate. 

we can still get snow with the southeast ridge if we got polar air just north of here

[SnoSki14]

5 hours ago, snowman19 said:

You are going to get cutters with a full latitude -PNA trough in the west and a SE ridge. Keep following the wish casters and believe that a huge cold and snowstorm pattern is inbound. It’s hilarious

Agree this time.

Pattern looks like trash. Maybe it won't be a blowtorch but it's definitely not a snowy pattern

[MJO812]

1 hour ago, RippleEffect said:

we can still get snow with the southeast ridge if we got polar air just north of here

Yep

[MJO812]

3 minutes ago, SnoSki14 said:

Agree this time.

Pattern looks like trash. Maybe it won't be a blowtorch but it's definitely not a snowy pattern

You will be singing a different tune once the models adjust to the change.

[Dan76]

[MJO812]

 

[inter]

Not sure if some posters are serious or are using reverse psychology to will some snow into existence.

[CIK62]

Previous three runs were Trace only.      A little better on latest---but it is the often tampered with 18Z:

[RedSky]

13 minutes ago, inter said:

Not sure if some posters are serious or are using reverse psychology to will some snow into existence.

It's called unbridled enthusiasm, one step from delusions of grandeur 

 

[MJO812]

1 hour ago, MJO812 said:

You will be singing a different tune once the models adjust to the change.

I'm wrong here ?