December 2021

[bluewave]

We have built up some pretty high temperature departures on the month so far. NYC….+5.7…EWR…+7.2….LGA….+6.2….JFK…..+5.9. With the much warmer 1991-2020 climate normals, all we need is a +3 or higher to finish in the top 10 warmest Decembers. The latest ensembles have around a +2 to +3 in the means for the next 10 days.

 

 

 

 

[snowman19]

48 minutes ago, NittanyWx said:

 

The problem is the 2 sigma block sitting over the Aleutians instead of the GOA.  That's driving the PNA tank.

 

Once again the American suite overamped the VP signal in an area where standing wave/seasonal interference during well developed Nina's occur, got people to bite on it, then backed off on the signal closer in.  I've lost count how many times I've seen the American suite do that.

 

If the Pacific isn't gonna help at all its gonna be a struggle. 

Great post as always. At least a pro met said what I’ve been saying the last month. I can’t get accused of anything now lol

[snowman19]

35 minutes ago, NittanyWx said:

 

Neither of those dislodge a decent source airmass into eastern Canada when the Pacific looks like it does.   Tuesday a great example..you get a coastal low with no air and no HP. 

Storms can happen in these patterns, but it's a thread the needle situation and those generally don't work out well for this area.

Just trapping PAC maritime air underneath 

[NittanyWx]

40 minutes ago, EasternLI said:

Happy new year from the 12Z EPS 

 

You'd want that GOA ridge to nudge east a bit more to really dislodge that cement, but if it can hold onto this for a few runs it would at least be a step in the right direction 

[SnoSki14]

51 minutes ago, snowman19 said:

Just trapping PAC maritime air underneath 

Theres plenty of cold air around but it's focused out west. Canada is very cold as well.

Places that don't normally get snow out west will get plenty of it. Seattle & Vancouver and most of BC will see an unusual amount of cold & snow.

[MJO812]

2 hours ago, EasternLI said:

Happy new year from the 12Z EPS 

End of this month into January is going to be nice.  Phase 7 is good for us in January.

[EastonSN+]

3 hours ago, NittanyWx said:

 

You'd want that GOA ridge to nudge east a bit more to really dislodge that cement, but if it can hold onto this for a few runs it would at least be a step in the right direction 

 

Thanks

This is an earlier shot of the EPS. Understand that the core of the cold is definitely west, however wouldn't we have enough cool air for front end overrunning situations even at this timeframe?  

I feel like 1992/93 had a lot of 1 to 3 inch storms (changeover to rain events) with almost a coast to coast trough. 

I may be wrong but I feel like the below could produce in the same way, especially central and northern areas of this forum.

 

[Roger Smith]

I have a good feeling about Jan 3-6, could be a rather slow transition until then. 

[donsutherland1]

Colder air will begin to return to the region tonight and tomorrow. Monday morning could see the coldest readings so far this season, but the cold shot will be a brief one. Temperatures will likely moderate beginning on Tuesday. The final week of December could see temperatures begin to turn colder as month comes to a close. No severe cold is likely.

Afterward, if the small sample of cases where the MJO moved into Phase 7 at a high amplitude (1.75 or above) during the December 10-20 period, as occurred this month, is representative, the first 10 days of January could see below to perhaps much below normal temperatures. Support for such an outcome has increased on the recent guidance. Currently, the risk of severe cold at the start of January remains relatively low. There remains uncertainty concerning the magnitude and duration of the cold during the first 10 days of January.

In the Midwest, Chicago has yet to receive its first measurable snowfall through 4 pm CST on December 18. Only December 2012 saw saw its first measurable snowfall after December 16 (December 20).

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 -1.4°C and the Region 3.4 anomaly was -1.1°C for the week centered around December 8. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -1.00°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 +8.93 today.

The preliminary Arctic Oscillation (AO) figure was -0.889 today.

On December 16 the MJO was in Phase 6 at an amplitude of 2.005 (RMM). The December 15-adjusted amplitude was 1.974 (RMM).

Based on sensitivity analysis applied to the latest guidance, there is an implied 94% probability that New York City will have a warmer than normal December (1991-2020 normal). December will likely finish with a mean temperature near 42.4° (3.3° above normal).

 

[RippleEffect]

it's always 10 days from now!

[the_other_guy]

10 minutes ago, RippleEffect said:

it's always 10 days from now!

Only in a bad pattern when you are desperately looking for a new pattern.

We had a very warm fall.

Nov eeked out a negative. That was with the new baseline and it was barely negative.

The latest guidance for the rest of December doesn’t look great. The fat lady hasn’t started singing yet but she’s warming up for December.

We have also gone into a very dry pattern…Which we haven’t had much of lately.

This isn’t how good winters start.

[MJO812]

Hard to take the op runs they change with every run

[MJO812]

1 hour ago, jfklganyc said:

Only in a bad pattern when you are desperately looking for a new pattern.

We had a very warm fall.

Nov eeked out a negative. That was with the new baseline and it was barely negative.

The latest guidance for the rest of December doesn’t look great. The fat lady hasn’t started singing yet but she’s warming up for December.

We have also gone into a very dry pattern…Which we haven’t had much of lately.

This isn’t how good winters start.

Its not even winter and there are signs of a change going on right now.

People are so impatient 

[MJO812]

Huge block on the gfs

Everything is getting shunt further to the south on this run

[MJO812]

18 minutes ago, MJO812 said:

Hard to take the op runs they change with every run

Rjay knows I'm right so he has to weenie me

 

[EasternLI]

EPS at 00z started the changes a day earlier than the 12z yesterday did. New years eve. So now we're facing this look at the end of the run.

[Snowlover11]

sleet/ice pellets falling here in yonkers, very light but you hear the little ping against the car

[bluewave]

7 hours ago, MJO812 said:

Its not even winter and there are signs of a change going on right now.

People are so impatient 

It’s not a matter of being impatient. We just don’t want to be in the NYC below 3” December La Niña club. Very disappointing to see things getting pushed back now into early January. 
 

The new 91-20 climate normals seasonal snowfall in NYC is 29.8”. NYC has never reached 30.0” in a La season with under 3.0” in December since 1950. This must be related to the fact that the good La Niña years for snowfall get off to an early start since they are front-loaded.

NYC December snowfall during La Ninas and seasonal snowfall.

2017…..7.7….40.9

2016….3.2….30.2

2011…..0.0….7.4

2010….20.1….61.9

2008….6.0…..27.6

2007….2.9……11.9

2005….9.7……40.0

2000….13.4…..35.0

1999…….T…….16.3

1998…..2.0……12.7

1995…..11.5…..75.6

1988…..0.3……8.1

1984…..5.5…..24.1

1975…..2.3…..17.3

1974……0.1…..13.1

1973…..2.8….23.5

1971…….T……22.9

1970……2.4….15.5

1964……3.1….24.4

1955…...3.3…33.5

1954…...0.1….11.5

1949……1.5….14.0

[thunderbolt]

8 minutes ago, bluewave said:

It’s not a matter of being impatient. We just don’t want to be in the NYC below 3” December La Niña club. Very disappointing to see things getting pushed back now into early January. 
 

 

The new 91-20 climate normals seasonal snowfall in NYC is 29.8”. NYC has never reached 30.0” in a La season with under 3.0” in December since 1950. This must be related to the fact that the good La Niña years for snowfall get off to an early start since they are front-loaded.

NYC December snowfall during La Ninas and seasonal snowfall.

2017…..7.7….40.9

2016….3.2….30.2

2011…..0.0….7.4

2010….20.1….61.9

2008….6.0…..27.6

2007….2.9……11.9

2005….9.7……40.0

2000….13.4…..35.0

1999…….T…….16.3

1998…..2.0……12.7

1995…..11.5…..75.6

1988…..0.3……8.1

1984…..5.5…..24.1

1975…..2.3…..17.3

1974……0.1…..13.1

1973…..2.8….23.5

1971…….T……22.9

1970……2.4….15.5

1964……3.1….24.4

1955…...3.3…33.5

1954…...0.1….11.5

1949……1.5….14.0

I guess the next question ask yourself what were the strengths of all those ?

[MJO812]

31 minutes ago, bluewave said:

It’s not a matter of being impatient. We just don’t want to be in the NYC below 3” December La Niña club. Very disappointing to see things getting pushed back now into early January. 
 

 

The new 91-20 climate normals seasonal snowfall in NYC is 29.8”. NYC has never reached 30.0” in a La season with under 3.0” in December since 1950. This must be related to the fact that the good La Niña years for snowfall get off to an early start since they are front-loaded.

NYC December snowfall during La Ninas and seasonal snowfall.

2017…..7.7….40.9

2016….3.2….30.2

2011…..0.0….7.4

2010….20.1….61.9

2008….6.0…..27.6

2007….2.9……11.9

2005….9.7……40.0

2000….13.4…..35.0

1999…….T…….16.3

1998…..2.0……12.7

1995…..11.5…..75.6

1988…..0.3……8.1

1984…..5.5…..24.1

1975…..2.3…..17.3

1974……0.1…..13.1

1973…..2.8….23.5

1971…….T……22.9

1970……2.4….15.5

1964……3.1….24.4

1955…...3.3…33.5

1954…...0.1….11.5

1949……1.5….14.0

It's a back to back Nina

 

[EasternLI]

Oh wow, this is really cool. 

 

[MJO812]

Got this from SNE  subforum

Pattern turns alot better after Christmas

 

Courtesy of Orh

[MJO812]

10 minutes ago, bluewave said:

The long range EPS takes the forcing back into the IO in mid -January. So it’s uncertain how long that early January forecast  pattern lasts. We’ll probably get some more clues with the weeklies tomorrow.

 

Having the MJO stall in 7 and then going to 8 is helping us out here. The longer it takes the better for us.

[CIK62]

The next 8 days are averaging 39degs.(34/44), or +5>>>+2 nowadays.

Month to date is  46.5[+5.8].       Should be  43.3[+4.6] by the 27th.

Reached 52 here yesterday.

Today: 40-41 early, 28 by tomorrow AM., wind nw and breezy, clearing late.

42*(85%RH) here at 6am, left over drizzle.{was 50 at Midnite}   41* at 7am.      40* at 9am.      39* at 10am.      38* at Noon.         35* at 6pm.        32* at 9pm.       30* at 11pm.

[SnoSki14]

58 minutes ago, bluewave said:

It’s not a matter of being impatient. We just don’t want to be in the NYC below 3” December La Niña club. Very disappointing to see things getting pushed back now into early January. 
 

 

The new 91-20 climate normals seasonal snowfall in NYC is 29.8”. NYC has never reached 30.0” in a La season with under 3.0” in December since 1950. This must be related to the fact that the good La Niña years for snowfall get off to an early start since they are front-loaded.

NYC December snowfall during La Ninas and seasonal snowfall.

2017…..7.7….40.9

2016….3.2….30.2

2011…..0.0….7.4

2010….20.1….61.9

2008….6.0…..27.6

2007….2.9……11.9

2005….9.7……40.0

2000….13.4…..35.0

1999…….T…….16.3

1998…..2.0……12.7

1995…..11.5…..75.6

1988…..0.3……8.1

1984…..5.5…..24.1

1975…..2.3…..17.3

1974……0.1…..13.1

1973…..2.8….23.5

1971…….T……22.9

1970……2.4….15.5

1964……3.1….24.4

1955…...3.3…33.5

1954…...0.1….11.5

1949……1.5….14.0

On its face no December snowfall in a Nina is bad but we've seen a lot of things that we've never had before lately. 

Maybe this could be the first time we see 30"+ after 0" in December in a Nina.

[MJO812]

1 minute ago, SnoSki14 said:

On its face no December snowfall in a Nina is bad but we've seen a lot of things that we've never had before lately. 

Maybe this could be the first time we see 30"+ after 0" in December in a Nina.

It will be

This will not be a shutout winter 

[EasternLI]

8 minutes ago, bluewave said:

The long range EPS takes the forcing back into the IO in mid -January. So it’s uncertain how long that early January forecast  pattern lasts. We’ll probably get some more clues with the weeklies tomorrow.

 

Yeah it's going to be interesting seeing what transpires. That's a bit of a strange solution there. La Niña base state is subsidence in the Indian ocean. Would be impressive to pull that off. Not saying it's not possible though. Gefs doing funky things this morning. Eps doesn’t jive with it. I feel like we might have to wait it out a little bit to get a clearer picture. Would like to see better agreement. 

[MJO812]

4 minutes ago, EasternLI said:

Yeah it's going to be interesting seeing what transpires. That's a bit of a strange solution there. La Niña base state is subsidence in the Indian ocean. Would be impressive to pull that off. Not saying it's not possible though. Gefs doing funky things this morning. Eps doesn’t jive with it. I feel like we might have to wait it out a little bit to get a clearer picture. Would like to see better agreement. 

Mjo on the euro is now starting to move  towards 8 but slowly.  It was mostly stuck near 6/7

https://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ecmf.shtml

[MJO812]

How come snowman didn't post this ?

 

 

[donsutherland1]

Morning thoughts…

Clouds will break from west to east as the day progresses. Temperatures will only rise slightly as colder air pours into the region. High temperatures will likely reach the upper 30s and perhaps lower 40s in most of the region. Likely high temperatures around the region include:

New York City (Central Park): 42°

Newark: 44°

Philadelphia: 45°

Normals:

New York City: 30-Year: 43.3°; 15-Year: 44.1°

Newark: 30-Year: 43.8°; 15-Year: 44.8°

Philadelphia: 30-Year: 45.0°; 15-Year: 46.0°

Tomorrow will be fair but unseasonably cold. Milder air will likely return on Tuesday.