December 2021

[donsutherland1]

10 minutes ago, Great Snow 1717 said:

they may be thinking  "those winter enthusiasts on the east coast have a lot of time on their hands" lol

Probably.

[LoboLeader1]

 

[snowman19]

2 hours ago, bluewave said:

Maybe the extreme marine heatwave during the summer near Japan was a precursor to the record fall into winter NEPAC vortex and supercharged Pacific Jet?
 

 

 

Big questions ahead for the end of the month and January: 

 

 

[bluewave]

35 minutes ago, snowman19 said:

Big questions ahead for the end of the month and January: 

The only La Niña MJO composite that comes close to the pattern this month is a January phase 5. All the ensembles keep this pattern going through at least the solstice. Maybe the MJO will make more sense near the end of December and beginning of January.

 

[Eduardo]

3 hours ago, Allsnow said:

Definitely changes in the epo coming around the 20th. It will take some time for it to cool down here, especially with the Uber -pna. 

I'd love to see it, but I'm skeptical.  You'd also have to do something about that pesky -PNA before a -EPO can lean on the SE ridge too.  You'd think that the pool of anomalously cold SST near western S. America would have to serve us well at some point though, even if the NPAC looks like (not-so) hot garbage.

[Allsnow]

6 minutes ago, Eduardo said:

I'd love to see it, but I'm skeptical.  You'd also have to do something about that pesky -PNA before a -EPO can lean on the SE ridge too.  You'd think that the pool of anomalously cold SST near western S. America would have to serve us well at some point though, even if the NPAC looks like (not-so) hot garbage.

Agree. The eps continues to show the -epo/ridge bridge at the end of the 11-15 day. Unfortunately, the -pna is allowing all the cold to dump into the west. This is at the end of the 11-15 day so I’m sure things will change before then. 

[dmillz25]

1 hour ago, snowman19 said:

Big questions ahead for the end of the month and January: 

 

 

Of course you show that part of the thread lol

[SnoSki14]

Well I guess we're back to our single snow squall winter then. 

[donsutherland1]

26 minutes ago, Allsnow said:

Agree. The eps continues to show the -epo/ridge bridge at the end of the 11-15 day. Unfortunately, the -pna is allowing all the cold to dump into the west. This is at the end of the 11-15 day so I’m sure things will change before then. 

Hopefully, it will hold to the EPO- idea. Unfortunately, the long-range EPS is often prone to show an EPO- that ultimately does not materialize. We'll probably know more in a few more days.

[Allsnow]

8 minutes ago, donsutherland1 said:

Hopefully, it will hold to the EPO- idea. Unfortunately, the long-range EPS is often prone to show an EPO- that ultimately does not materialize. We'll probably know more in a few more days.

I think the way the mjo is progressing it has merit. Now can we shake that -pna? 

[MJO812]

23 minutes ago, SnoSki14 said:

Well I guess we're back to our single snow squall winter then. 

According to what ?

[bluewave]

Funny how parts of the area have had a top 10 snowiest month every season since 09-10. 
 

09-10…..Dec…..Feb…..

10-11…….Dec…..Jan

11-12…….Oct

12-13……Nov…Feb….Nemo

13-14……Jan….Feb

14-15……Jan….Feb…Mar

15-16…….Jan

16-17……..Mar….Stella interior 

17-18……..Mar….30” at ISP

18-19……..Nov

19-20……..May

20-21….….Feb

[donsutherland1]

Colder air has now moved into place. A system could bring a little light snow or flurries to parts of the region tomorrow. Little or no accumulation is likely. A light accumulation remains possible in eastern New England.

Behind the system Thursday will be another cool day. Milder air will begin to overspread the region on Friday. Temperatures could soar to near record and record levels on Saturday.

No Arctic blasts appear likely for the foreseeable future. Overall, through December 20th, temperatures will likely be warmer than normal in the means with some short-lived cool shots.

Out West, Denver has yet to see its first measurable snowfall through December 6. The previous record latest first measurable snowfall occurred on November 21, 1934. The progression of Denver's latest first measurable snowfall of the season is as follows:

November 11, 1882
November 16, 1894
November 19, 1931
November 21, 1934

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). By December 20th, the mean temperature will likely be somewhere between 43.1° and 45.7°. 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.

Although the MJO moved into Phase 6 at a very high amplitude in recent days, the sample size of cases where the MJO moved into Phase 6 at an amplitude of 1.75 or above during December 1-15 is very small (n=5). Moreover, just a single case occurred during a predominantly EPO+/AO+ pattern and none occurred during a La Niña. Among those five cases, two had a cold or very cold December 21-31 period, one saw near normal conditions, and two had warm conditions. In short, the current high amplitude MJO does not provide a clear signal where things are headed.

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 +11.62 today.

The preliminary Arctic Oscillation (AO) figure was +2.924 today

On December 5 the MJO was in Phase 6 at an amplitude of 1.919 (RMM). The December 4-adjusted amplitude was 2.144 (RMM).

Based on sensitivity analysis applied to the latest guidance, there is an implied 79% probability that New York City will have a warmer than normal December (1991-2020 normal). December will likely finish with a mean temperature near 42.0° (2.9° above normal).

 

[bluewave]

Big upgrade coming for the EPS next year.

 

• Created by Carsten Maass on Dec 06, 2021

Go to start of metadata

 

Description of the upgrade

With IFS Cycle 48r1, the horizontal resolution of the medium-range ensemble (ENS) will increase from 18 to 9 km. This will bring the ENS to the same horizontal resolution as the high resolution forecast (HRES). The vertical resolution for both ENS and HRES will remain at 137 model levels. 

Cycle 48r1 will also bring a major upgrade to the configuration of the extended-range ensemble (ENS extended): The forecasts will start from day 0, rather than being an extension of the medium-range forecasts starting at day 15, it will run daily, rather than twice-weekly, and the number of perturbed forecasts will increase from 50 to 100. The resolution will remain unchanged at 36 km horizontally and 137 model levels.

The implementation of Cycle 48r1 is currently planned for late 2022 and it will be the first new scientific model upgrade to run in ECWMF's new Data Centre in Bologna. 

While no action is required at this time, as much notice as possible is given to users to plan and prepare for this increased resolution. Please note, at this lead time implementation date and content of this cycle are subject to change - please watch this page for further updates. 

 

Implementation scheduled for late 2022, TBC

 

[Allsnow]

1 hour ago, bluewave said:

Big upgrade coming for the EPS next year.

 

• Created by Carsten Maass on Dec 06, 2021

Go to start of metadata

 

Description of the upgrade

With IFS Cycle 48r1, the horizontal resolution of the medium-range ensemble (ENS) will increase from 18 to 9 km. This will bring the ENS to the same horizontal resolution as the high resolution forecast (HRES). The vertical resolution for both ENS and HRES will remain at 137 model levels. 

Cycle 48r1 will also bring a major upgrade to the configuration of the extended-range ensemble (ENS extended): The forecasts will start from day 0, rather than being an extension of the medium-range forecasts starting at day 15, it will run daily, rather than twice-weekly, and the number of perturbed forecasts will increase from 50 to 100. The resolution will remain unchanged at 36 km horizontally and 137 model levels.

The implementation of Cycle 48r1 is currently planned for late 2022 and it will be the first new scientific model upgrade to run in ECWMF's new Data Centre in Bologna. 

While no action is required at this time, as much notice as possible is given to users to plan and prepare for this increased resolution. Please note, at this lead time implementation date and content of this cycle are subject to change - please watch this page for further updates. 

 

Implementation scheduled for late 2022, TBC

 

Weeklies every day now 

[snowman19]

2 hours ago, donsutherland1 said:

Hopefully, it will hold to the EPO- idea. Unfortunately, the long-range EPS is often prone to show an EPO- that ultimately does not materialize. We'll probably know more in a few more days.

Even if the -EPO is real, it’s -EPO with a severely negative PNA, +AO, +NAO, a SE ridge and a strong SPV. The cold would dump into the west first, then struggle to make it to our latitude on the east coast 

[donsutherland1]

16 minutes ago, snowman19 said:

Even if the -EPO is real, it’s -EPO with a severely negative PNA, +AO, +NAO, a SE ridge and a strong SPV. The cold would dump into the west first, then struggle to make it to our latitude on the east coast 

I suspect that it will begin to turn cooler during the last 10 days of the month, but not severely cold. The PNA looks to stay negative to strongly negative for the foreseeable future. My worry is that the EPO briefly goes negative but then rebounds limiting the opportunity for notable cold (maybe a two week period?) over the next 30 days.

[bluewave]

Mid-December is on track to be  the 3rd warmest for the entire CONUS averaged out. You can see how many top 10 warmest years there have been since 2001. This is coming after one of the warmest first weeks of December for parts of the country. So there should be some very impressive warm departures by the solstice.
 

[LoboLeader1]

Currently 36* here under a partly cloudy sky. High of 39* today.

[StormchaserChuck!]

2 hours ago, donsutherland1 said:

Out West, Denver has yet to see its first measurable snowfall through December 6. The previous record latest first measurable snowfall occurred on November 21, 1934. The progression of Denver's latest first measurable snowfall of the season is as follows:

November 11, 1882
November 16, 1894
November 19, 1931
November 21, 1934

 

Good post.. I wonder if any other place has gone 85 years, then blown past it like this. I remember you posted about AK record Summer warmth by 2 degrees, and PHX the next year record warmth by 2 whole degrees. 

[LoboLeader1]

10 minutes ago, bluewave said:

Mid-December is on track to be  the 3rd warmest for the entire CONUS averaged out. You can see how many top 10 warmest years there have been since 2001. This is coming after one of the warmest first weeks of December for parts of the country. So there should be some very impressive warm departures by the solstice.
 

Any chance we could see record breaking temps on x-mas eve like we did (64* in NYC) back on 12/24/2015?

[EasternLI]

Seems like the weeklies have been struggling with the mjo. I remember the euro/eps weren't very good during tropical season. Wondering if this could be a related issue. Otoh, I realize it's terribly difficult to model the mjo correctly. 

 

[bkviking]

Joe B quoting our very own Don S. 

[the_other_guy]

3 hours ago, bluewave said:

Mid-December is on track to be  the 3rd warmest for the entire CONUS averaged out. You can see how many top 10 warmest years there have been since 2001. This is coming after one of the warmest first weeks of December for parts of the country. So there should be some very impressive warm departures by the solstice.
 

So youre saying we are lucky that our deps are so low compared to the mid section?

[LibertyBell]

11 hours ago, bluewave said:

Funny how parts of the area have had a top 10 snowiest month every season since 09-10. 
 

09-10…..Dec…..Feb…..

10-11…….Dec…..Jan

11-12…….Oct

12-13……Nov…Feb….Nemo

13-14……Jan….Feb

14-15……Jan….Feb…Mar

15-16…….Jan

16-17……..Mar….Stella interior 

17-18……..Mar….30” at ISP

18-19……..Nov

19-20……..May

20-21….….Feb

how come no April in here?  we got 6 inches in April just a few years ago

 

[LibertyBell]

15 hours ago, bluewave said:

Maybe the extreme marine heatwave during the summer near Japan was a precursor to the record fall into winter NEPAC vortex and supercharged Pacific Jet?
 

 

 

whats causing the Pacific to be so hot and is that why we're seeing late season typhoons there right now

 

[CIK62]

The next 8 days are averaging  45degs.(39/52), or +8.

Reached 47 yesterday{at Midnite} and 45 in the PM.

Today: 40-43, wind variable e.,to s., to nw., cloudy-drizzle?      Wait for the 22nd.    If a BN period starts then, the CFS says it will stick all winter.    Big Talk or Just Squawk?

39*(53%RH) here at 6am.     42* at 9am.      46* at Noon.       44* at 3pm.      41* at 6pm.

[bluewave]

Looks like the record warmth building to our west will come out in waves. Our first chance for record warmth will be on Saturday. Models have mid 60s for the warm spots with the record high at Newark at 65°. Then the ridge builds again next week with a another push of warmth coming east.

 

Newark Area, NJ
Version: 16.2 (created 2021-11-30)
Period of record: 1931 through 2020

12/11

65 in 1971

65 in 1966

63 in 1979

Saturday

 

Next week

 

 

[LoboLeader1]

33 here this AM. 

[bluewave]

We need to get rid of that -PNA trough near the West Coast to see improvements after Christmas.