December 2021

[EasternLI]

5 minutes ago, LibertyBell said:

its not the end of the world if there is 0 measurable snow this season, that would actually be historic and fun to see.  It also considerably increases the odds for seeing a historic positive season in the next few years based on the last 20 years.

 

Won't happen. We'll find a fluke event in March or something. Would be unprecedented though.

[psv88]

12 minutes ago, LibertyBell said:

its not the end of the world if there is 0 measurable snow this season, that would actually be historic and fun to see.  It also considerably increases the odds for seeing a historic positive season in the next few years based on the last 20 years.

 

No, it would be the end of the world and would not be fun to see no snow. 
 

we will see snow by second week of January as the -PNA relaxes. 
 

we are better off with a favorable PAC and an unfavorable ATL then the reverse. So less focus on ATL blocking IMHO, and more on the PAC. At least until we move deeper into the winter. We’ve had plenty of blocking patterns with no snow or storms, but pop a stout PNA ridge and things happen 
 

until then, we close the shades and try and stay healthy 

[SnowGoose69]

1 hour ago, snowman19 said:

No surprise there. The problem is the record PAC jet, severe -PNA and actually the -NAO block, it’s shearing everything to bits. This is going to continue unabated right through the 1st week of January, at the very least: 

 Look how ridiculously dry The extended EPS is for the next 46 days:  

 

 

The -NAO is less effective earlier in winter...I posted in the MA forum that this same pattern 6-8 weeks from now with differing wavelengths probably results in the SER being non existent or way flatter.  The good news is that historically in a small sample size that -NAO/-PNA patterns that have set in around 12/15-12/20 have tended to result in a -NAO for the rest of the winter.  

[SnowGoose69]

1 hour ago, bluewave said:

Maybe we need another El Niño to change up the winter North Pacific pattern. The Super El Niño in 15-16 shifted the ridge axis west. It had been further east in 13-14 and 14-15. But the common denominator seems to be the record WPAC warm pool generating these giant stationary waves .

 

 

 

 

The last couple of El Ninos in essence acted like La Ninas...even the 15-16 El Nino the December pattern was nothing like 83/97...it was sort of more like 72...I believe for sure that in a -PDO regime that even in a Nino you risk having a SE ridge pattern if you cannot get other things to line up for a +PNA

[donsutherland1]

Temperatures rose into the 40s today. Tomorrow will be another mild day before a brief push of modestly colder air knocks down temperatures on Thursday. Overall, temperatures will generally be near or above normal throughout much of the remainder of December. No severe cold is likely through the remainder of December.

It will be a different story in the Pacific Northwest. Near record to record cold, along with snowfall, is possible during the closing days of December in such cities as Portland, Seattle, and Vancouver.

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. However, the coldest air will likely remain confined to the Pacific Northwest, Northern Plains, and western and central Canada for much of this period.

January will likely commence with an AO-/PNA- pattern. That typically favors somewhat cooler than normal readings in the East. For NYC, the January 1-10, 1991-2020 mean temperature for such cases was 33.5° (normal: 34.8°). There are some hints that a milder pattern could begin to develop around mid-January.    

In the Midwest, through 4 pm today, Chicago has yet to receive its first measurable snowfall. The old record latest first measurable snowfall was December 20, 2012.

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 -27.14 today. That is the lowest value since June 20, 2020 when the SOI was -33.95.

The preliminary Arctic Oscillation (AO) figure was -1.453 today.

On December 19 the MJO was in Phase 7 at an amplitude of 1.611 (RMM). The December 18-adjusted amplitude was 1.677 (RMM).

Based on sensitivity analysis applied to the latest guidance, there is an implied 98% probability that New York City will have a warmer than normal December (1991-2020 normal). December will likely finish with a mean temperature near 42.7° (3.6° above normal).

 

[EasternLI]

1 hour ago, bluewave said:

The record WPAC warm pool has turned into an extreme Rossby wave  generating machine. Last summer it was the record ridge and heatwave over the PACNW. This month the record ridge is centered south of the Aleutians. 

 

Agree with that, emphatically. This is a powerful force this year. 200mb streamfunction reveals a commanding presence. Also, no surprise, right where it needs to be for a -PNA. 

[wdrag]

fwiw... I think we're going to see an ice problem tonight in spots vcnty ABE-12N-BAF, cities excluded but rural areas not.  Already 32.4/23.8 at 515PM here at my house in Wantage and have noticed models trending toward more ice.  Presuming it -precipitates here between 05z-15z... then I think the RGEM is on it.  daytime cycles HRRRX, HRRR, EC/GFS all slightly colder.  Just a matter of qpf occurring. No thread: all the ice obs can be placed into the nw suburbs thread.  

[LibertyBell]

43 minutes ago, psv88 said:

No, it would be the end of the world and would not be fun to see no snow. 
 

we will see snow by second week of January as the -PNA relaxes. 
 

we are better off with a favorable PAC and an unfavorable ATL then the reverse. So less focus on ATL blocking IMHO, and more on the PAC. At least until we move deeper into the winter. We’ve had plenty of blocking patterns with no snow or storms, but pop a stout PNA ridge and things happen 
 

until then, we close the shades and try and stay healthy 

reminds me of 93-94 when the Pac was great and the NAO was (extremely) positive look at what kind of a winter that was

 

[Brian5671]

1 minute ago, LibertyBell said:

reminds me of 93-94 when the Pac was great and the NAO was (extremely) positive look at what kind of a winter that was

 

This is nothing like 93-94

[MJO812]

Pure insanity

[SnowGoose69]

24 minutes ago, Brian5671 said:

This is nothing like 93-94

 

Yeah 93-94 was like 13-14 (I believe I have the year right on that) where the NAO was positive and even the AO for periods but the EPO was insanely negative.

[KEITH L.I]

1 hour ago, LibertyBell said:

thats why I see people predicting an el nino for next winter and not just an el nino but a strong one (see main forum)

 

As of now looks like a weak el Nino for next year. Anything beats this horrible pattern.

[eduggs]

59 minutes ago, wdrag said:

fwiw... I think we're going to see an ice problem tonight in spots vcnty ABE-12N-BAF, cities excluded but rural areas not.  Already 32.4/23.8 at 515PM here at my house in Wantage and have noticed models trending toward more ice.  Presuming it -precipitates here between 05z-15z... then I think the RGEM is on it.  daytime cycles HRRRX, HRRR, EC/GFS all slightly colder.  Just a matter of qpf occurring. No thread: all the ice obs can be placed into the nw suburbs thread.  

Agree about the ice. It's mentioned in the NWS forecast discussions but I think overall it's likely to catch some people off guard. On radar and short range guidance, it looks like the precip is coming and will be fairly far NW. Even if it's mostly drizzle, it could cause isolated problems.

[StormchaserChuck!]

1 hour ago, bluewave said:

Imagine if we had a favorable Pacific to go with extreme Greenland block.

 

Good post, I wonder if global climate evolution would return to normal if we had several years of big -NAO.. 

Quote

pure insanity 

Seattle had 19" of rain last month, which I think was an all time record. 

[donsutherland1]

4 minutes ago, StormchaserChuck! said:

Good post, I wonder if global climate evolution would return to normal if we had several years of big -NAO.. 

Seattle had 19" of rain last month, which I think was an all time record. 

Seattle had its wettest fall (19.04”) on record.

Climate change is a function of forcings, not internal variability. The persistent NAO- would not change the ongoing energy imbalance that is resulting from an enhanced greenhouse effect.

[StormchaserChuck!]

10 minutes ago, donsutherland1 said:

Seattle had its wettest fall (19.04”) on record.Thanks

Climate change is a function of forcings, not internal variability. The persistent NAO- would not change the ongoing energy imbalance that is resulting from an enhanced greenhouse effect.

To even out with the Pacific patterns in dominance, we need a +700 to +900dm -NAO. 

[snowman19]

2 hours ago, LibertyBell said:

its not the end of the world if there is 0 measurable snow this season, that would actually be historic and fun to see.  It also considerably increases the odds for seeing a historic positive season in the next few years based on the last 20 years.

 

In the last 30 years, I think only 1 winter came close to a 0 snowfall total winter and that was 01-02, all the other duds still had notable snow events during the Dec-Mar time frame, which would include 97-98, 11-12, 19-20

[SnoSki14]

2 minutes ago, snowman19 said:

In the last 30 years, I think only 1 winter came close to a 0 snowfall total winter and that was 01-02, all the other duds still had notable snow events during the Dec-Mar time frame, which would include 97-98, 11-12, 19-20

I'd be shocked if we get 0 snowfall. 

I'm actually expecting us to get 30" mostly in late winter.  

[LoboLeader1]

Parts of FLA maybe colder than some areas here come Thurs AM.

 

[SnowGoose69]

34 minutes ago, SnoSki14 said:

I'd be shocked if we get 0 snowfall. 

I'm actually expecting us to get 30" mostly in late winter.  

Its really hard to get shutout.  Many think the 72-73 record is pretty close to untouchable for NYC although we did come really close in 97-98 and 01-02 to breaking it.  I think its just remarkably difficult though to avoid 1 or 2 events even in bad winters and that usually pushes you over 2.8 inches

[Allsnow]

 

[EasternLI]

18z gefs is taking this new mjo wave from phase 6 and really amplifying it now in phase 7. Don't know if that happens but that's the first run (gefs or eps) I've seen doing that. 

[EasternLI]

Little bit of action in the strat too that run. Wondering if that's related. That would make sense. 

[wdrag]

No sure if anyone is seeing mping reports to our southwest PHL area to near DC with spotty freezing drizzle, ice pellets and snow?  Not sure about the snow but an interesting night for ice is coming I think for nw NJ.  

[EasternLI]

10 minutes ago, WestBabylonWeather said:

I’m not familiar with the MJO. 
 

I decided to read up on it a bit

 

seems record snows and higher chances of snow occurs during phases 7 and 8 here in the northeast. Why is that? 

Research indicates it's more phase 8 for NE snowstorms. There's a paper somewhere out there on that. The reason is that it's capable of altering the jet orientation to be more favorable for such events. The phases are just different locations where tropical convection is active. It can be much more complicated, but that's the basic idea. 

[Oliviajames]

28 minutes ago, WestBabylonWeather said:

I’m not familiar with the MJO. 
 

I decided to read up on it a bit

 

seems record snows and higher chances of snow occurs during phases 7 and 8 here in the northeast. Why is that? 

Also to add the convection (thunderstorms) cause ridging in certain areas and then troughs in certain areas.  

[HeadInTheClouds]

22 minutes ago, wdrag said:

No sure if anyone is seeing mping reports to our southwest PHL area to near DC with spotty freezing drizzle, ice pellets and snow?  Not sure about the snow but an interesting night for ice is coming I think for nw NJ.  

And possibly HV. 27 right now. 

[hudsonvalley21]

27 minutes ago, wdrag said:

No sure if anyone is seeing mping reports to our southwest PHL area to near DC with spotty freezing drizzle, ice pellets and snow?  Not sure about the snow but an interesting night for ice is coming I think for nw NJ.  

Currently 28/25 here. It will be interesting too see where the temperatures go later when the clouds set in. Could be some icy spots in the am.

[LibertyBell]

4 hours ago, Brian5671 said:

This is nothing like 93-94

No dude I meant that was a year with a terrible atlantic and great pacific

 

[LibertyBell]

2 hours ago, snowman19 said:

In the last 30 years, I think only 1 winter came close to a 0 snowfall total winter and that was 01-02, all the other duds still had notable snow events during the Dec-Mar time frame, which would include 97-98, 11-12, 19-20

97-98 was super close we just had a renegade oddball event in late March that I dont even remember.  I think 01-02 has to rank as the least severe winter in my lifetime but 97-98 is right behind it