December 2021

[MJO812]

 

[snowman19]

9 minutes ago, MJO812 said:

 

 

[MJO812]

Gfs coming in with a coastal storm for the 21

 

[NEG NAO]

26 minutes ago, snowman19 said:

 

Who is more skilled in predicting long range JB or Dr. Lee ?

[NEG NAO]

Just now, MJO812 said:

Gfs coming in with a coastal storm for the 21

 

Intense Coastal Hugger - need this further offshore a few miles for the metro to cash in IMO in December with still too warm water........

[MJO812]

Nice storm but warm for the coast. Signal is strong for some type of storm.

[NEG NAO]

1 minute ago, MJO812 said:

Nice storm but warm for the coast. Signal is strong for some type of storm.

Until the Euro and GFS ensembles  comes on board and we get several  runs in a row of consistency confidence will increase IMO

[Rjay]

11 minutes ago, MJO812 said:

Nice storm but warm for the coast. Signal is strong for some type of storm.

2' in Philly.  3" in Wilmington, DE 

[MJO812]

1 minute ago, Rjay said:

2' in Philly.  3" in Wilmington, DE 

Yep and check out snj lol

[RippleEffect]

3 minutes ago, MJO812 said:

Yep and check out snj lol

Canadian?

[MJO812]

12 minutes ago, RippleEffect said:

Canadian?

Similar to gfs

Heavy snow inland and coastal hugger

 

[MJO812]

[Intensewind002]

9 minutes ago, MJO812 said:

Im going home to long island for Christmas break tomorrow and I’ll be dead if Albany gets 2 ft of snow within a week of me leaving

[WeatherFox]

NEG NAO

Posted 47 minutes ago

   50 minutes ago,  MJO812 said: 

Nice storm but warm for the coast. Signal is strong for some type of storm.

Expand  

Until the Euro and GFS ensembles  comes on board and we get several  runs in a row of consistency confidence will increase IMO
 

Agree!

[MJO812]

3 minutes ago, WeatherFox said:

 

NEG NAO

Posted 47 minutes ago

   50 minutes ago,  MJO812 said: 

Nice storm but warm for the coast. Signal is strong for some type of storm.

Expand  

Until the Euro and GFS ensembles  comes on board and we get several  runs in a row of consistency confidence will increase IMO
 

Agree!

Cmc was just upgraded 

[NorthShoreWx]

1 hour ago, MJO812 said:

Nice storm but warm for the coast. Signal is strong for some type of storm.

Looks like a diamond in the rough for fishy snow lovers south of central LI.  And a 24" snowfall gradient over about 3 blocks in South Jersey.  Something is fishy about this map.  

[LibertyBell]

17 hours ago, bluewave said:

It’s easier to get pattern improvements after January 20th in El Niño years since they are back-loaded like 15-16. But we want to start putting snow points on the board by the end of December in La Ninas to reach normal snowfall. That’s why the December the 3” rule for NYC has worked out every La Niña since the 1990s. La Niña years that we have to wait until after January 20th for a decent snow like 99-00 usually underperform in the snowfall department.

But couldn't that just be a random thing?  I remember several la ninas that barely made it to 3" in December and then were awful in January and then we had one big snowstorm in February to get most of our seasonal snowfall.  05-06 comes to mind immediately.

 

By the way in that specific case that rule doesn't apply to JFK because JFK didn't get anywhere near 3" in December and they still got to average or slightly above average snowfall for the season thanks to the February snowstorm.

 

I'm trying to make a point that we can't simply use ENSO as our only method for making forecasts....other forces are at play.

 

 

 

[LibertyBell]

1 hour ago, MJO812 said:

Told you to move to the Poconos, 17.4 inches right over my house there lol. and it's only a little over 2 hours from NYC so you could easily commute back and forth.  Screw the coast, it's going to be underwater soon enough anyway and everyone will be moving inland and to higher elevations.

[WeatherFox]

1 hour ago, MJO812 said:

Cmc was just upgraded 

Let’s go Canada!

[WeatherFox]

3 minutes ago, LibertyBell said:

Told you to move to the Poconos, 17.4 inches right over my house there lol. and it's only a little over 2 hours from NYC so you could easily commute back and forth.  Screw the coast, it's going to be underwater soon enough anyway and everyone will be moving inland and to higher elevations.

Better yet, retire and move to Florida and track canes. After a while SNOW gets old.

[LibertyBell]

2 minutes ago, WeatherFox said:

Better yet, retire and move to Florida and track canes. After a while SNOW gets old.

True lol, I hate shoveling snow.

 

[LibertyBell]

17 hours ago, donsutherland1 said:

Building on yesterday's post concerning the pattern evolution, the prospects of a colder than normal start to January have continued to increase.  The MJO has now moved into Phase 7 at a very high amplitude (2.000 or above). The number of cases where the MJO moved into Phase 7 at amplitudes of 2 or above (n=3) or 1.75 or above (n=4) during December 10-20 is small. However, those cases overwhelmingly saw January 1-10 wind up colder or perhaps much colder than normal.

January 1-10 Temperatures for New York City and Philadelphia:

New York City:
Mean: 26.1°
Lowest: 21.2°, 2018
Highest: 34.1°, 2002
1991-2020 Mean: 34.8°

Philadelphia:
Mean: 26.1°
Lowest: 20.7°, 2018
Highest: 34.5°, 2002
1991-2020 Mean: 35.2°

lol damn 2001-02 somehow still gets on this list.  So the pattern did improve in Jan 2002 with a -NAO but it led to the historic suppressed Carolina snowstorm.

 

[LibertyBell]

14 hours ago, forkyfork said:

the gfs shows the problem with a -pna. this wave goes south of us but is too weak and we get light rain. the next wave amplifies and cuts too far west

is this why we didn't get big snow in 2001-02 even when the -NAO happened in January and coastal Carolina got their historic snowstorm instead?

 

[LibertyBell]

13 hours ago, dWave said:

Come to think of it, March avg snowfall usually is greater than Dec anyway. I remember when the normal Dec snow was around 2.5", then the next normals update jumped to under 5", thanks to more of the snowy 2000s in the mix. March avg I always remember being around 5".  I don't know what the 90-2020 Dec avgs are by month. The difference between Dec and Mar has become more pronounced now, but I never look at Dec as reliably snowy. It can get decent snow but it feels equally unsurprising to get very little or a trace.  

December and March both averaged around 6" prior to the 70s.

 

[LibertyBell]

13 hours ago, Stormlover74 said:

Yeah 2000 and 2010 along with 02, 03, 05 and 09 really skewed those averages. March has remained fairly steady

snowcover is much better in December, I haven't had any March snow that stuck around more than a day

And no 10" March snowfalls here....

 

[LibertyBell]

13 hours ago, bluewave said:

No doubt. We will need to weaken the -PNA enough in late December into early January for the -EPO and -NAO to work for us. We can all remember how the models kept showing LR snowstorms through most of December 2010. We had an epic -NAO and -AO but the -PNA shut down the snowfall until the PNA went positive around Christmas. That was a very cold pattern through most of the month but the -PNA messed with the favorable storm tracks.

if a -NAO and -AO become strong enough can they build back west far enough to knock down the -PNA?

 

[LibertyBell]

10 hours ago, donsutherland1 said:

I believe we will probably see a cooler period during the first 10 days of January given the atmospheric response to the MJO’s move into Phase 7 at a very high amplitude. I am not sure whether there will be severe cold nor whether such a pattern would persist more than 2 weeks. It’s possible most of the severe cold will remain confined to the west. 

dont want severe cold here, that would mean dry and suppression

 

[LibertyBell]

9 hours ago, EasternLI said:

Yeah, recent research has really shown its a very important piece of the puzzle. Plus, this particular year, there's even more to that. La nina plus EQBO plus low solar (which lags ~3 years) cumulatively increases the North Atlantic response to said mjo. So the base state is primed to be very receptive. It's all a big part of the reason I got interested at the possible progression earlier this month. Now it's all about to get underway and I'm fascinated to see how this all goes.

https://journals.ametsoc.org/view/journals/clim/33/1/jcli-d-18-0811.1.xml?tab_body=fulltext-display

As shown by the spatial correlation resultsofFig. 10and the SLP/SAT diagnostic results ofFig. 11,composites for combined SMIN/cool ENSO, SMIN/QBOE, and SMIN/QBOE/cool ENSO conditions produce progressively stronger MJO modulations of meanSLP and SAT anomalies in the North Atlantic/Eurasiansector. These results are consistent with previous workshowing that the QBO interacts with other low-frequency stratospheric signals such as the 11-yr solarcycle

the connection to the 11 yr solar cycle is particularly interesting because it also reflects the spike in heat every 11 years

 

[LibertyBell]

9 hours ago, brooklynwx99 said:

I continue to remain confident on a wholesale change to the 500mb pattern over the next 10 days... this is mainly due to the strong MJO wave propagating towards the dateline, which will provide the impetus for -EPO ridging, as well as the anomalous Scandinavian trough which will retrograde into the NAO domain. 

The MJO is currently in Phase 7, and looks to make a break for Phase 8 as well within the next 10 - 14 days, which is favorable for high-latitude blocking and cold air intrusions into the E/C US. Although there have been some murmurs about the -ENSO interfering with the propagation of the wave, having it die before reaching Phase 8 with high amplitude, the -QBO state often allows for stronger, slower waves. This should allow for the MJO to continue its propagation through favorable phases.

The Scandinavian ridge that's been talked about since the beginning of the month is now starting to form in the short range, and will reach +2.5 sigma:

This cutoff ridge will retrograde towards Greenland, providing stout -NAO blocking that will, in turn, lead to significant confluent flow over Nova Scotia. This should keep the SE ridge at bay even with the -PNA. There will also be a great cold feed into the US from the -EPO forced by the MJO, which is a complete 180 from what we've been seeing recently. Both of these drivers should lead to a coast-to-coast trough, which becomes more apparent towards each of these runs:

 

I've heard a lot of concerns about the -PNA, and I don't believe that they're totally founded. We will probably have to deal with the SE ridge before the blocking is fully established, but once the -NAO begins to retrograde, the compression of heights in SE Canada will ensue. This almost always crushes the SE ridge and allows for redevelopment of any systems that would try to cut. So it might be a problem towards the 20th, but the maturation of the blocking should allow for confluence to take over.

Anomalous -NAO blocks like this have the potential to completely overwhelm patterns, and this one looks to become more and more west-based over time, which is optimal. If anything, a +PNA here would likely lead to supression until the block eventually decays. The negative anomalies throughout the Atlantic also lead me to believe that this is a legitimate -NAO, as the flow in that region is completely backed up.

The high-latitude blocking will also lead to dramatic heat fluxes into the stratosphere, which look to constantly disrupt the SPV. I don't believe that the SPV will be able to consistently strengthen, and a weakening of the SPV may allow for prolonged blocking. A SSW isn't on the way as of now, but that would significantly disrupt -ENSO climo if it were to occur, and this would certainly be a step in the right direction. 

This December will almost certainly finish with a -NAO/-PNA combo. The Januaries that historically followed Decembers with a -NAO/-PNA featured favorable patterns for the E US with a significant west-based -NAO:

Overall, I am quite excited for the end of the month, as things get very interesting any time we see blocking of this magnitude. I expect the SE ridge to continue to correct weaker as the -NAO trends stronger with time (as hemispherically forced -NAOs usually do), allowing for a coast-to-coast trough look. This would be the "just cold enough" type pattern where waves roll under the block with good climo. Hopefully we continue to see these corrections as we endure a dismal pattern through the 20th.

Wasn't 1966-67 one of the winters that fit the pattern you described above?

[LibertyBell]

8 hours ago, EasternLI said:

Given the la nina went east based, coupled with a -PDO, favors -NAO. I posted the paper earlier in the thread about this. 

 

Not sure why people should have a problem with a weak or moderate Niña to begin with. Only weak Niño would be more preferred.

Yeah it's idiotic when people try to simplify everything down to ENSO

That chart is pretty obvious..... use 50" snowfall winters as the cut off..... 4 were weak la ninas and 5 were neutral.