December 2023

[vegan_edible]

looking through ensembles and im not necessarily seeing some sort of blowtorch scenario unfolding, just 40's and seasonable air through the holidays. i dont know the extent of which this will hold but the big 3 (GEFS, EPS, CMC) all seem to have us locked in on that look. 12z OP GFS seems to allow some cooler air to flood in after the storm on the 18th, obvious take that with a *big* grain of salt but i feel as though this winter is not gonna be all doom and gloom and we do have the have chances to score with january climo

[brooklynwx99]

17 minutes ago, NittanyWx said:

 

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.

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

[NittanyWx]

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. 

 

 

[JustinRP37]

30 minutes ago, Volcanic Winter said:

For the record I’m not really seeing much in the way of bickering right now and thought this has been a rather congenial back and forth of various concerns and viewpoints. 

Definitely better than at some earlier junctures IMO. 

Appreciating all the insights shared right now. 

For sure, but it does seem many are saying it hasn't been cold at all recently and given the state of the ski season thus far, things are pretty good. Sure the extreme SNE resorts aren't there yet, but looking ahead things look seasonable. NYC's averages drop from the low 50s Dec, to low 40s by NYE (not exactly frigid by any take).

And before I'm weenied, I told friends and family that I am expecting DJF to average around +1 to +2.5 overall with about 60-70% of our average snowfall season. Still a "warm" winter but not snowless and certainly not the ratter we had last year. 

[bluewave]

2 hours ago, Brian5671 said:

Too much Twitter/hype garbage with a pattern change 12/20 and "disruptive travel week" for xmas blahblahblah, people lap up that stuff like a hungry lion and a steak

It’s as if the Boxing Day Blizzard flipped the switch to very little snowfall from December 20th-31st. This has become one of our least snowy 10-11 day periods of winter. The most disruptive Christmas event of the last decade was the flood cutter in 2020 which wiped out the BGM 40” snowpack leading to all the flash flooding. 
 

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

Ending Date	Total Snowfall Dec 20 to Dec 31	Missing Count
2022-12-31	T	0
2021-12-31	0.2	0
2020-12-31	T	0
2019-12-31	T	0
2018-12-31	T	0
2017-12-31	0.7	0
2016-12-31	T	0
2015-12-31	T	0
2014-12-31	T	0
2013-12-31	T	0
2012-12-31	0.4	0
2011-12-31	0.0	0
2010-12-31	20.0	0

[40/70 Benchmark]

2 hours ago, snowman19 said:

As long as there is a massive vortex in the EPO region, Canada and the CONUS are going to get flooded with PAC air, cutting off cross-polar flow, equivalent to a big Chinook across North America. It won’t matter what the AO/NAO do in that case, they will just trap PAC air underneath the high latitude blocking

The NAO/AO are not totally irrelevant, though...you can see in the December temp anomaly chart that it kept the NE from torching even more...while that doesn't matter in December, I think it would in a month to six weeks from now. But we all agreed this would not be a very cold year and I agree that Pacific is more important. 

[Volcanic Winter]

15 minutes ago, bluewave said:

It’s as if the Boxing Day Blizzard flipped the switch to very little snowfall from December 20th-31st. This has become one of our least snowy 10-11 day periods of winter. The most disruptive Christmas event of the last decade was the flood cutter in 2020 which wiped out the BGM 40” snowpack leading to all the flash flooding. 
 

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

Ending Date	Total Snowfall Dec 20 to Dec 31	Missing Count
2022-12-31	T	0
2021-12-31	0.2	0
2020-12-31	T	0
2019-12-31	T	0
2018-12-31	T	0
2017-12-31	0.7	0
2016-12-31	T	0
2015-12-31	T	0
2014-12-31	T	0
2013-12-31	T	0
2012-12-31	0.4	0
2011-12-31	0.0	0
2010-12-31	20.0	0

What did NYC get in Dec 09? I have to go back to old pics but I was in Long Branch for that storm and it at least had to be high teens. Cars were buried and shoveling out sucked. It was glorious. 

Crazy to have high level back to back punches in Dec and then a long string of nothing. 

[weatherpruf]

48 minutes ago, JustinRP37 said:

For sure, but it does seem many are saying it hasn't been cold at all recently and given the state of the ski season thus far, things are pretty good. Sure the extreme SNE resorts aren't there yet, but looking ahead things look seasonable. NYC's averages drop from the low 50s Dec, to low 40s by NYE (not exactly frigid by any take).

And before I'm weenied, I told friends and family that I am expecting DJF to average around +1 to +2.5 overall with about 60-70% of our average snowfall season. Still a "warm" winter but not snowless and certainly not the ratter we had last year. 

As long as this winter remains mild and I can get out fishing and catch up on all those years I missed while slaving away at a desk, I'm good. 

[bluewave]

8 minutes ago, Volcanic Winter said:

What did NYC get in Dec 09? I have to go back to old pics but I was in Long Branch for that storm and it at least had to be high teens. Cars were buried and shoveling out sucked. It was glorious. 

Crazy to have high level back to back punches in Dec and then a long string of nothing. 

Double digit event on the 19-20th. 
 

Data for December 19, 2009 through December 20, 2009
Click column heading to sort ascending, click again to sort descending.

State	Name	Station Type	Total Snowfall
NY	SHOREHAM 1.8 SSE	CoCoRaHS	29.0
NY	ISLIP-LI MACARTHUR AP	WBAN	23.9
NY	EAST MORICHES 0.6 WNW	CoCoRaHS	23.2
NY	RIVERHEAD RESEARCH FARM	COOP	20.0
NY	JAMESPORT 0.6 SSW	CoCoRaHS	20.0
NY	BAITING HOLLOW	COOP	19.0
NY	ISLIP 0.2 NW	CoCoRaHS	17.0
NY	JFK INTERNATIONAL AIRPORT	WBAN	14.5
NY	OCEANSIDE	COOP	14.2
CT	NORWICH PUBLIC UTILITY PLANT	COOP	14.0
NY	NORTHPORT 1.6 NNE	CoCoRaHS	13.8
NY	LEVITTOWN 0.2 E	CoCoRaHS	13.5
NY	FLORAL PARK 0.4 W	CoCoRaHS	13.5
NJ	NEWARK LIBERTY INTL AP	WBAN	11.2
NY	CENTERPORT	COOP	11.0
NY	NY CITY CENTRAL PARK	WBAN	10.9
NY	MINEOLA	COOP	10.2

[Volcanic Winter]

6 minutes ago, bluewave said:

Double digit event on the 19-20th. 
 

Data for December 19, 2009 through December 20, 2009
Click column heading to sort ascending, click again to sort descending.

State	Name	Station Type	Total Snowfall
NY	SHOREHAM 1.8 SSE	CoCoRaHS	29.0
NY	ISLIP-LI MACARTHUR AP	WBAN	23.9
NY	EAST MORICHES 0.6 WNW	CoCoRaHS	23.2
NY	RIVERHEAD RESEARCH FARM	COOP	20.0
NY	JAMESPORT 0.6 SSW	CoCoRaHS	20.0
NY	BAITING HOLLOW	COOP	19.0
NY	ISLIP 0.2 NW	CoCoRaHS	17.0
NY	JFK INTERNATIONAL AIRPORT	WBAN	14.5
NY	OCEANSIDE	COOP	14.2
CT	NORWICH PUBLIC UTILITY PLANT	COOP	14.0
NY	NORTHPORT 1.6 NNE	CoCoRaHS	13.8
NY	LEVITTOWN 0.2 E	CoCoRaHS	13.5
NY	FLORAL PARK 0.4 W	CoCoRaHS	13.5
NJ	NEWARK LIBERTY INTL AP	WBAN	11.2
NY	CENTERPORT	COOP	11.0
NY	NY CITY CENTRAL PARK	WBAN	10.9
NY	MINEOLA	COOP	10.2

Thank you. Found this as well, definitely high teens for my location at the time. 
 

https://www.weather.gov/media/phi/StormReports/DEC19-202009.pdf

That was one of my favorite storms ever for various circumstantial life reasons (I met my now wife summer 09, we just moved in together while I was attending school at MU). 

[North and West]

What did NYC get in Dec 09? I have to go back to old pics but I was in Long Branch for that storm and it at least had to be high teens. Cars were buried and shoveling out sucked. It was glorious. 
Crazy to have high level back to back punches in Dec and then a long string of nothing. 

Regression to the mean.


.

[Dark Star]

1 hour ago, vegan_edible said:

looking through ensembles and im not necessarily seeing some sort of blowtorch scenario unfolding, just 40's and seasonable air through the holidays. i dont know the extent of which this will hold but the big 3 (GEFS, EPS, CMC) all seem to have us locked in on that look. 12z OP GFS seems to allow some cooler air to flood in after the storm on the 18th, obvious take that with a *big* grain of salt but i feel as though this winter is not gonna be all doom and gloom and we do have the have chances to score with january climo

We're wasting "sun angle"

[Volcanic Winter]

9 minutes ago, North and West said:

Regression to the mean.


.

Of course. They’re anomalous events, but clearly “possible.” Was just interesting to having back to back hard hitters like that, with Boxing Day a clear all time great storm for those that cashed in. 

[bluewave]

21 minutes ago, Volcanic Winter said:

Thank you. Found this as well, definitely high teens for my location at the time. 
 

https://www.weather.gov/media/phi/StormReports/DEC19-202009.pdf

That was one of my favorite storms ever for various circumstantial life reasons (I met my now wife summer 09, we just moved in together while I was attending school at MU). 

That December 2000 to 2010 record was the first 11 year run with 5 double digit snowfall years since the 1880s. The 1940s were great also with 3 double digit years.

 

Monthly Total Snowfall for NY CITY CENTRAL PARK, NY
Click column heading to sort ascending, click again to sort descending.

Year	Dec	Season
Mean	8.9	8.9
2010	20.1	20.1
2009	12.4	12.4
2008	6.0	6.0
2007	2.9	2.9
2006	0.0	0.0
2005	9.7	9.7
2004	3.0	3.0
2003	19.8	19.8
2002	11.0	11.0
2001	T	T
2000	13.4	13.4

 

Monthly Total Snowfall for NY CITY CENTRAL PARK, NY
Click column heading to sort ascending, click again to sort descending.

Year	Dec	Season
Mean	7.5	7.5
1880	11.5	11.5
1881	1.3	1.3
1882	0.0	0.0
1883	22.6	22.6
1884	10.7	10.7
1885	T	T
1886	10.3	10.3
1887	9.0	9.0
1888	T	T
1889	6.0	6.0
1890	11.4	11.4

 

Monthly Total Snowfall for NY CITY CENTRAL PARK, NY
Click column heading to sort ascending, click again to sort descending.

Year	Dec	Season
Mean	8.7	8.7
1940	3.0	3.0
1941	0.3	0.3
1942	8.5	8.5
1943	T	T
1944	6.7	6.7
1945	15.6	15.6
1946	1.3	1.3
1947	30.2	30.2
1948	25.3	25.3
1949	1.3	1.3
1950	3.8	3.8

 

 

[Volcanic Winter]

Thank you @bluewave . I do feel it’s slightly disingenuous to act like we shouldn’t expect snow in Dec, just not with the frequency or consistency of Jan and Feb. And it’s certainly the most likely winter month to strike out on, especially nowadays. 

I view it as sort of a subconscious psychological cope for recent years, with absolutely no disrespect intended. I have plenty of my own of those. 

And of course I’m not speaking of expecting monster storms every Dec, but flakes should be flying. We were shown how much Dec has warmed and combined with any already extant decadal variability we’re definitely losing opportunities here. 

[bluewave]

30 minutes ago, Volcanic Winter said:

Thank you @bluewave . I do feel it’s slightly disingenuous to act like we shouldn’t expect snow in Dec, just not with the frequency or consistency of Jan and Feb. And it’s certainly the most likely winter month to strike out on, especially nowadays. 

I view it as sort of a subconscious psychological cope for recent years, with absolutely no disrespect intended. I have plenty of my own of those. 

And of course I’m not speaking of expecting monster storms every Dec, but flakes should be flying. We were shown how much Dec has warmed and combined with any already extant decadal variability we’re definitely losing opportunities here. 

It seems like the start of the more hostile Pacific pattern began in December 11. But it didn’t become more widespread through the winters until 18-19.  So in the last 13 Decembers including this one, we only had 3 with a favorable enough Pacific for 6”+ snows in NYC. The years were 2013, 2017, and 2020. Allsnow gets credit for calling the December 2020 pattern potential pretty early. 

 

[Stormlover74]

36 minutes ago, Volcanic Winter said:

Thank you @bluewave . I do feel it’s slightly disingenuous to act like we shouldn’t expect snow in Dec, just not with the frequency or consistency of Jan and Feb. And it’s certainly the most likely winter month to strike out on, especially nowadays. 

I view it as sort of a subconscious psychological cope for recent years, with absolutely no disrespect intended. I have plenty of my own of those. 

And of course I’m not speaking of expecting monster storms every Dec, but flakes should be flying. We were shown how much Dec has warmed and combined with any already extant decadal variability we’re definitely losing opportunities here. 

And flakes did fly a couple times last week and again last night and this morning not far away even in what's been a very warm month. Many places to our south and west have surpassed all of last winter already...albeit not hard to do when they had <1"

[lee59]

Looks like the models trending a little chillier over the next week or two.

[winterwx21]

14 minutes ago, lee59 said:

Looks like the models trending a little chillier over the next week or two.

It does look like a decent brief cold shot for Wednesday night into Thursday. We might struggle to hit 40 on Thursday, but we'll be right back to highs near 50 for Friday and the weekend.

Overall it looks like a lot of average to slightly above average temps for the rest of December, and a pretty dry pattern. Boring times ahead. Looks as if it will be awhile before we have anything interesting to talk about.

Hopefully we'll see significant changes for January. In the meantime at least we have football and the holiday season to enjoy. 

[Volcanic Winter]

At least I have the vibe!

[Allsnow]

Wow @Torch Tiger

 

 

[vegan_edible]

7 minutes ago, Allsnow said:

Wow

 

 

 

[psv88]

5 hours ago, bluewave said:

Double digit event on the 19-20th. 
 

Data for December 19, 2009 through December 20, 2009
Click column heading to sort ascending, click again to sort descending.

State	Name	Station Type	Total Snowfall
NY	SHOREHAM 1.8 SSE	CoCoRaHS	29.0
NY	ISLIP-LI MACARTHUR AP	WBAN	23.9
NY	EAST MORICHES 0.6 WNW	CoCoRaHS	23.2
NY	RIVERHEAD RESEARCH FARM	COOP	20.0
NY	JAMESPORT 0.6 SSW	CoCoRaHS	20.0
NY	BAITING HOLLOW	COOP	19.0
NY	ISLIP 0.2 NW	CoCoRaHS	17.0
NY	JFK INTERNATIONAL AIRPORT	WBAN	14.5
NY	OCEANSIDE	COOP	14.2
CT	NORWICH PUBLIC UTILITY PLANT	COOP	14.0
NY	NORTHPORT 1.6 NNE	CoCoRaHS	13.8
NY	LEVITTOWN 0.2 E	CoCoRaHS	13.5
NY	FLORAL PARK 0.4 W	CoCoRaHS	13.5
NJ	NEWARK LIBERTY INTL AP	WBAN	11.2
NY	CENTERPORT	COOP	11.0
NY	NY CITY CENTRAL PARK	WBAN	10.9
NY	MINEOLA	COOP	10.2

Loved this storm. Got 16” in Melville. Loved watching that mega death band spiral in west from the ocean. 

[wdrag]

I continue interested in a decent widespread weather event 17th-21st... if it all plays right, enough cold air to the north as short waves seem to be digging a little more across the northeast USA than modeled a few days ago (mid week and early this weekend) and that could leave the nw fringes interesting, as a large Southeast USA coastal storm heads  northeast. Long long ways to go... We'll have to see if the GEFS loses its very nice late weekend-early next week 5H flow pattern. 

[Roger Smith]

Another history note on Dec 11, 1944 .. Toronto had its heaviest calendar day snowfall, 19 inches, with 3 additional after 00h a total of 22" fell, second only to 23" in Dec (25-26) 1872 during easterly winds in frigid weather, that one was a lake effect event. 

[donsutherland1]

In the wake of the storm that brought heavy rain and gusty winds to the region, a period of cooler weather will settle into the region. However, temperatures could again rise to above and perhaps much above normal levels as the winter solstice approaches.

No Arctic air appears likely through the remainder of December. However, a transition to a colder pattern could commence during the first week of January.

The ENSO Region 1+2 anomaly was +1.3°C and the Region 3.4 anomaly was +1.9°C for the week centered around December 6. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +1.97°C and the ENSO Region 3.4 anomaly has averaged +1.92°C. A basinwide El Niño event is ongoing. El Niño conditions will may strengthen somewhat further this month.  

The SOI was -1.87 today.

The preliminary Arctic Oscillation (AO) was -0.747 today. Strong blocking in the final week of November, as occurred this year, has often been followed by frequent blocking in December and January.

On December 9 the MJO was in Phase 5 at an amplitude of 1.862 (RMM). The December 8-adjusted amplitude was 1.766 (RMM).

Based on sensitivity analysis applied to the latest guidance, there is an implied 74% probability that New York City will have a warmer than normal December (1991-2020 normal). December will likely finish with a mean temperature near 41.2° (2.1° above normal).

 

[wdrag]

Prepping for a likely (70% chance in my mind) topic issuing either this evening or Wednesday for the period late Sunday the 17th through Wednesday morning the 20th. Looks to me like a sizable nor-easter with marginally cold enough air (850 MB and surface temp ensembles) nearby to the north and northwest for snow potential at least down to the i84 corridor inclusive of nw NJ and maybe trickling down to the CT coast at the storms end.

But the main story probably is rainfall potential... I've added the EPS probability of 1" or greater rain in 24 hours centered Monday the 18th.  This event could put out isolated 4" rainfall for some part of our area.

Wind gusts will be a concern but as most have noted, model guidance tends to be a touch high... still I would not rule out a wind hazard for the coast.

For initiating this topic... prefer to give the ensembles at least another 12 - 24 hours to agree a little more and for the EPS to be consistent (GEFS-CMCE not quite as far west and that is my concern). No matter this southern system will be a big wet one for at least Texas, and probably the Gulf Coast, and in my opinion up the southeast coast to our area.

Ensembles probably not holding on to the upper low long enough as we go into the middle of next week.

This won't be a big deal if qpf remains at or below 1" and little or no snow... but potential exists for something significantly larger as a nor'easter.  Compared to this past storm... way too early for me to express confidence one way or the other.  Depends on eventual track of the upper low so I have to wait... it's about potential and I think this event will have plenty of interest up here in a few days.   Can it get up here as per the EPS or does it get deflected out to sea?

 

[lee59]

2 hours ago, wdrag said:

Prepping for a likely (70% chance in my mind) topic issuing either this evening or Wednesday for the period late Sunday the 17th through Wednesday morning the 20th. Looks to me like a sizable nor-easter with marginally cold enough air (850 MB and surface temp ensembles) nearby to the north and northwest for snow potential at least down to the i84 corridor inclusive of nw NJ and maybe trickling down to the CT coast at the storms end.

But the main story probably is rainfall potential... I've added the EPS probability of 1" or greater rain in 24 hours centered Monday the 18th.  This event could put out isolated 4" rainfall for some part of our area.

Wind gusts will be a concern but as most have noted, model guidance tends to be a touch high... still I would not rule out a wind hazard for the coast.

For initiating this topic... prefer to give the ensembles at least another 12 - 24 hours to agree a little more and for the EPS to be consistent (GEFS-CMCE not quite as far west and that is my concern). No matter this southern system will be a big wet one for at least Texas, and probably the Gulf Coast, and in my opinion up the southeast coast to our area.

Ensembles probably not holding on to the upper low long enough as we go into the middle of next week.

This won't be a big deal if qpf remains at or below 1" and little or no snow... but potential exists for something significantly larger as a nor'easter.  Compared to this past storm... way too early for me to express confidence one way or the other.  Depends on eventual track of the upper low so I have to wait... it's about potential and I think this event will have plenty of interest up here in a few days.   Can it get up here as per the EPS or does it get deflected out to sea?

 

Thanks for this update, this is looking more interesting this morning.

[bluewave]

The one bright spot with near record warm CONUS December patterns is lower heating bills.

 

[Rjay]

13 hours ago, winterwx21 said:

It does look like a decent brief cold shot for Wednesday night into Thursday. We might struggle to hit 40 on Thursday, but we'll be right back to highs near 50 for Friday and the weekend.

Overall it looks like a lot of average to slightly above average temps for the rest of December, and a pretty dry pattern. Boring times ahead. Looks as if it will be awhile before we have anything interesting to talk about.

Hopefully we'll see significant changes for January. In the meantime at least we have football and the holiday season to enjoy. 

Eps hours 90-360