December 2020 General Discussions & Observations Thread

[LibertyBell]

7 minutes ago, bluewave said:

3-21-18 was the last time that a the coast had heavier totals than inland.

https://www.weather.gov/okx/storm03212018

I remember that as the Central Long Island storm, in urbanized parts of western Long Island it was a nice storm but not as much as what we had on March 1, 2009 (granted the first day of March is more like late February than it is March.)

The one I remember most in that series was the April snowstorm that shut down the Yankee opener.

 

[NEG NAO]

Anyone remember this one ? 17th anniversary this weekend.

Snow and ice storm, December 5-6, 2003 - Storm Summary (raymondcmartinjr.com)

[Stormlover74]

Just now, NEG NAO said:

Anyone remember this one ? 17th anniversary this weekend.

Snow and ice storm, December 5-6, 2003 - Storm Summary (raymondcmartinjr.com)

Yep great 2 part storm

[Allsnow]

31 minutes ago, Stormlover74 said:

Yep great 2 part storm

Yep. That ULL really produced at night for the 2nd part

[MJO812]

2 hours ago, rossi said:

Hey is Paul Bastardis guy still on this forum?

No

[donsutherland1]

Colder air is now pushing into the region as a storm pulls away from the region. A period of cooler than normal to near normal temperatures will predominate over the next two weeks, with some occasional milder than normal temperatures.

There remains some uncertainty about the timing of the next change toward milder conditions. A milder pattern could develop toward the winter solstice. The closing 10 days of December could wind up generally warmer than normal. The duration of the current AO-/PNA+ pattern will be key to how long the developing colder pattern persists.

Statistical guidance based on the ENSO state and teleconnections would typically favor a colder regime for the first half of December in the Middle Atlantic and southern New England regions. Both historic experience following exceptionally warm November cases suggest that a warmer than normal December remains the base case even if the first half of the month winds up colder than normal. Almost 90% of cases with a November mean temperature of 51.5° or above in Central Park (2020 saw the temperature average a record 52.9° in November) went on to record a warmer than normal December and just over three-quarters of such cases saw December register a monthly mean temperature of 40.0° or above.

The ENSO Region 1+2 anomaly was -1.0°C and the Region 3.4 anomaly was -1.0°C for the week centered around November 18. 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 -1.40°C. La Niña conditions will likely prevail at least through the winter.

The SOI was +9.24.

Today, the preliminary Arctic Oscillation (AO) figure was -1.453. The preliminary PNA value was +1.650.

On December 4 the MJO was in Phase 4 at an amplitude of 1.018 (RMM). The December 3-adjusted amplitude was 0.965.

Based on the latest guidance, no significant stratospheric warming event is likely through the first two weeks of December. The warming above 3 mb in response to recent strong Wave 1 activity should abate toward the end of the second week of December.

Since 1950, there have been five cases where a La Niña developed during June-July-August or afterward following an El Niño winter. 4/5 (80%) of those cases saw a predominant EPO+/AO+ winter pattern. The most recent such case was 2016-17. 10/11 (91%) of the La Niña winters that followed an El Niño winter featured a predominantly positive EPO. A predominant EPO+/AO+ pattern is very likely for winter 2020-21. It is likely that the Middle Atlantic and southern New England areas will see a warmer than normal winter with below normal snowfall.

 

[MJO812]

So cruel

[LibertyBell]

5 hours ago, NEG NAO said:

Anyone remember this one ? 17th anniversary this weekend.

Snow and ice storm, December 5-6, 2003 - Storm Summary (raymondcmartinjr.com)

Yes indeed.  First part overperformed as the rain/snow line remained 5 miles south of the south shore and we got 8 inches from that and then the temps plummeted and I was convinced the second part would be even better with temps in the teens but the best dynamics went east of us and we only got 5 inches in the second part while Farmingdale ended up with 20 inches between the two parts of the storm.  That might have been the earliest 20 inch storm on any part of Long Island.  You have to be close to the rain/snow/mix line to get the best snows!

 

 

[CIK62]

For this time next week the EURO raised heights by 200m between last night's output and this morning's.          I think the GFS had a chance of snow next Sunday at this time last week, ie 14 days out.

Bleak snow outlook except for miracles, these next two weeks.         I always like to see a 3+day run of sub-32 Highs predicted---before I believe in significant snow chances----since a short-wave often meanders by in a period that is 72+ hours long.        Ideas where the system will bring in the cold with it, or generate its own cold air are too speculative.      Well so is CADamming.

****** I do remember that early season snowstorm.       Due to the Stillwell Ave. Subway Terminal renewal project at the time, I was forced to get off the Brighton Line at Sheepshead Bay Road and wait for the B-36 bus to complete the run to CI.       Long wait with blowing snow.      I believe this was in the morning as I was returning from a dental appointment---not from work.

[donsutherland1]

1 hour ago, LibertyBell said:

Yes indeed.  First part overperformed as the rain/snow line remained 5 miles south of the south shore and we got 8 inches from that and then the temps plummeted and I was convinced the second part would be even better with temps in the teens but the best dynamics went east of us and we only got 5 inches in the second part while Farmingdale ended up with 20 inches between the two parts of the storm.  That might have been the earliest 20 inch storm on any part of Long Island.  You have to be close to the rain/snow/mix line to get the best snows!

 

 

That was a really nice storm:

http://wintercenter.homestead.com/photodec2003b.html

 

 

[MJO812]

9 hours ago, Stormlover74 said:

Yep great 2 part storm

6 inches one day and then blizzard warning the next day with 8 inches of snow.

[CIK62]

The next 8 days are averaging 42degs. (37/47).          Making it 37degs., or about -1.0.       Unfortunately,  it shows 9 50-Degree Days in the next 16, threatening to make December a hoax wintertime month.     GFS Extended is a horror show.

CFS is AN everywhere in the US for the next 9 months, let alone this one.      Scary part was when I realized the T scale was in C!  eke!

Outside of atmospheric accidents----it is Over.     Laugh now, Die later.      This summer is part of the 11 year cycle curse 1933,44,55,66,77,88,99,2010,....2021.

38*(60%RH) here at 6am, scattered clouds.     37* at 7am.       36* at 10am.     40* at 3pm.

[the_other_guy]

33F. Still cant get below freezing 

[bluewave]

Several slightly cooler than average days coming up before another rebound back into the 50s.  Pacific flow will dominate with the models adjusting for a stronger +EPO. Same theme of long range guidance being biased too cool and showing too much blocking.
 

KNYC   GFSX MOS GUIDANCE  12/06/2020  0000 UTC                       
 FHR  24| 36  48| 60  72| 84  96|108 120|132 144|156 168|180 192      
 SUN  06| MON 07| TUE 08| WED 09| THU 10| FRI 11| SAT 12| SUN 13 CLIMO
 X/N  43| 30  41| 29  39| 32  43| 38  54| 41  50| 46  57| 51  55 31 44

 

 

[Brian5671]

20 minutes ago, bluewave said:

Several slightly cooler than average days coming up before another rebound back into the 50s.  Pacific flow will dominate with the models adjusting for a stronger +EPO. Same theme of long range guidance being biased too cool and showing too much blocking.
 

KNYC   GFSX MOS GUIDANCE  12/06/2020  0000 UTC                       
 FHR  24| 36  48| 60  72| 84  96|108 120|132 144|156 168|180 192      
 SUN  06| MON 07| TUE 08| WED 09| THU 10| FRI 11| SAT 12| SUN 13 CLIMO
 X/N  43| 30  41| 29  39| 32  43| 38  54| 41  50| 46  57| 51  55 31 44

 

 

same ol same ol-lots of fantasy blocking, nothing in reality.  This will turn out to be a 4 day cooldown to seasonable conditions before the torch returns

[White Gorilla]

Yawn.  Wake me when winter weather starts.  It is what it is.  I will try to see the upsides. 

[MJO812]

44 minutes ago, bluewave said:

Several slightly cooler than average days coming up before another rebound back into the 50s.  Pacific flow will dominate with the models adjusting for a stronger +EPO. Same theme of long range guidance being biased too cool and showing too much blocking.
 

KNYC   GFSX MOS GUIDANCE  12/06/2020  0000 UTC                       
 FHR  24| 36  48| 60  72| 84  96|108 120|132 144|156 168|180 192      
 SUN  06| MON 07| TUE 08| WED 09| THU 10| FRI 11| SAT 12| SUN 13 CLIMO
 X/N  43| 30  41| 29  39| 32  43| 38  54| 41  50| 46  57| 51  55 31 44

 

 

They love changing their tune everytime the models change .

 

But they are right.

The pattern on all the models is putrid.

December might be done 

[snowman19]

4 minutes ago, bluewave said:

This may turn out to be only the 2nd time that the MJO gets stuck in phases 4-5 for the whole month of December. At least last December, we had some cooler phases to start the month before it got to phase 4-5 mid to late month. So the warmth is no surprise given that MJO 4-5 in December is a classic +EPO pattern.

 

It looks like a ridiculously mild pattern is going to set up shop by the 15th. Consensus on all 3 major ensembles (EPS, GEPS, GEFS) now, along with the CFS 

[donsutherland1]

Morning thoughts...

Today will be partly to mostly sunny, breezy and cool. Temperatures will likely top out in the upper 30s and lower 40s in most of the region. Likely high temperatures around the region include:

New York City (Central Park): 41°

Newark: 43°

Philadelphia: 43°

Cool temperatures should persist through the middle of the week.

[MJO812]

14 minutes ago, bluewave said:

This may turn out to be only the 2nd time that the MJO gets stuck in phases 4-5 for the whole month of December. At least last December, we had some cooler phases to start the month before it got to phase 4-5 mid to late month. So the warmth is no surprise given that MJO 4-5 in December is a classic +EPO pattern.

 

Last December was also awful 

We really need to get out of  the LA Nina pattern

[MJO812]

2 minutes ago, bluewave said:

The  rapid expansion of the Indio-Pacific warm pool just keeps locking in these warmer MJO phases for us. So it’s very difficult to get any sustained winter cold. MJO phase 4-6 is essentially a mild La Niña pattern for us.

 

 

How were the MJO phases in the winter of 2010-2011? We really got lucky in the first half of that winter .

[romba]

I’m probably totally off base here, but where were these studies when we were buried under snow year in and year out just a few years back? Increased water temps lead to more snow and amped systems, until it doesn’t and then the increased warmth leads to warmth and no snow.

I’m not familiar with the research, but it just seems to match whatever temporary cycle we currently are in, which is a huge issue in general with data and research nowadays.

[bluewave]

36 minutes ago, MJO812 said:

How were the MJO phases in the winter of 2010-2011? We really got lucky in the first half of that winter .

The 10-11 winter was all about a continuation of the 187 year record -NAO pattern that  began in 09-10. So the record  -NAO had a greater influence than the MJO. We can remember how unfavorable the Pacific was from December 1-25 with all the fantasy snowstorms that showed up with the -PNA. But the -NAO set a record 500 height height anomaly in late December. This allowed a retrogression in heights boosting the PNA and setting up the record 60 inches of snow from late December to late January. But once the blocking faded in early February, we began to move toward a more +EPO +NAO that dominated the 11-12 winter.

https://rmets.onlinelibrary.wiley.com/doi/10.1002/wea.660

In conclusion, the winter of 2009/2010 was notable for the record negative NAO index in the 187‐year record of Jones etal. (1997), indicating the very unusual nature of atmospheric circulation over the Atlantic/European region. Despite 2009/2010 being a cold winter over the UK and Europe, it was actually around 0.5 to 1 degC warmer than might have been expected given this extreme pattern of atmospheric circulation. Considering observations averaged across the globe, winter 2009/2010 was one of the warmest on record.

[the_other_guy]

1 hour ago, snowman19 said:

It looks like a ridiculously mild pattern is going to set up shop by the 15th. Consensus on all 3 major ensembles (EPS, GEPS, GEFS) now, along with the CFS 

If we couldn’t believe the forecast more than five days out when it was cold, how come we preach gospel when its showing warmth? Because that is the default state?

Just curious.

On a separate note, this forums swings wildly through emotions by the day based on the latest model.

I enjoy the knowledge on here. But geez

[EastonSN+]

7 minutes ago, jfklganyc said:

If we couldn’t believe the forecast more than five days out when it was cold, how come we preach gospel when its showing warmth? Because that is the default state?

Just curious.

On a separate note, this forums swings wildly through emotions by the day based on the latest model.

I enjoy the knowledge on here. But geez

I think the forum would be optimistic if we had 2 good years in a row instead of 2 below average. This IO warm pool is most concerning as it seems to be dominating our weather and it's unrelenting. Question is when it will cool down 

[bluewave]

1 hour ago, romba said:

I’m probably totally off base here, but where were these studies when we were buried under snow year in and year out just a few years back? Increased water temps lead to more snow and amped systems, until it doesn’t and then the increased warmth leads to warmth and no snow.

I’m not familiar with the research, but it just seems to match whatever temporary cycle we currently are in, which is a huge issue in general with data and research nowadays.

You ask a very good question. As recently as 17-18, portions of Long Island had over 60” of snowfall  on the season. But this was also accompanied by record warmth and our first 80° reading on record for February. The record MJO actually had an influence on both. We got the extreme February warmth with a SSW. This was followed by the record snow in March. It turns out that strong MJO phases 5-7 can also lead to SSWs. But this isn’t always the case. So it can just as easily be warm without the snow like we saw last winter with the warm MJO phases. We can also see the MJO in the expanded  IO warm pool become more active in phases 1-3 with the record IOD like last November. This may have contributed to the record polar vortex last winter. 
 

http://s2sprediction.net/file/documents_publications/wcd-2020-17.pdf

Mechanisms and predictability of Sudden Stratospheric Warming in winter 2018

Finally, a composite analysis suggests that teleconnections associated with the record-breaking MJO phase 6 observed in the late January 2018 likely played a role in triggering this SSW event.

 

https://rmets.onlinelibrary.wiley.com/doi/full/10.1002/asl.1005

3.1 The winter 2019/20 NAO and November 2019 IOD
                                   

[Allsnow]

The MJO is croaking in 4/5 that’s not good for sustainable cold. We need something to shake the pattern up or it’s very meh. Lots of 40/50’s with rain 

[Stormlover74]

1 hour ago, jfklganyc said:

If we couldn’t believe the forecast more than five days out when it was cold, how come we preach gospel when its showing warmth? Because that is the default state?

Just curious.

On a separate note, this forums swings wildly through emotions by the day based on the latest model.

I enjoy the knowledge on here. But geez

Because there's been no consistent model consensus on it turning cold so if the pattern's been warm why would we expect that to change?

[White Gorilla]

2 hours ago, jfklganyc said:

If we couldn’t believe the forecast more than five days out when it was cold, how come we preach gospel when its showing warmth? Because that is the default state?

Just curious.

On a separate note, this forums swings wildly through emotions by the day based on the latest model.

I enjoy the knowledge on here. But geez

Warmth indeed seems to be the default state based on data.  

[Allsnow]