November 2017 Discussions & Observations Thread

[UlsterCountySnowZ]

1 hour ago, bluewave said:

The record Aleutian blocking ridge dropping the EPO has been our primary cold source in November. If the Aleutian ridge starts to fade with a more of a +EPO, then the  PAC Jet will produce a progressive pattern here with fast flow. The next several days of runs will be key  as to where this pattern is eventually headed.

Wouldn’t that Aleutian block be funneling in warmth if not for decending  QBO?

[donsutherland1]

With the AO forecast to drop to between -4.000 and -3.000 before rising toward late November and the PNA forecast to rise toward near neutral levels, it continues to appear that the second half of November will likely see readings average below normal for the period as a whole. A warmup toward the very end of the month remains possible.

Using the latest guidance, it appears that by November 20th, mean monthly temperature will fall to somewhere between 46.3° and 47.5° from yesterday’s 48.4° figure. That means November would be running between 2.0° and 3.2° below normal by that time. The implied probability for November’s finishing below normal has increased in recent days to about 68%. It is now very unlikely that autumn 2017 will become the warmest autumn on record.

[snowman19]

1 hour ago, bluewave said:

The record Aleutian blocking ridge dropping the EPO has been our primary cold source in November. If the Aleutian ridge starts to fade with a more of a +EPO, then the  PAC Jet will produce a progressive pattern here with fast flow. The next several days of runs will be key  as to where this pattern is eventually headed.

The -QBO has worked its way down to 50mb now. When you have a La Niña, HM has shown that combo works to flatten the Aleutuan ridge/high and cause downstream low heights/vortex over Alaska. You are starting to see this show up on the long range modeling for the end of this month. 

[donsutherland1]

On 11/13/2017 at 11:44 AM, Paragon said:

When was the last time either had three straight record lows? Wow.  Did Marthas Vineyard, Westhampton and Toms River all get down to 19 degrees Saturday Morning, Don?

JFK: March 24-27, 2014

EWR: May 19-22, 2002

Martha's Vineyard had a low temperature of 15° on November 12. Westhampton had a low temperature of 20° on November 12. I don't have data for Toms River.

 

[MJO812]

2 hours ago, snowman19 said:

The -QBO has worked its way down to 50mb now. When you have a La Niña, HM has shown that combo works to flatten the Aleutuan ridge/high and cause downstream low heights/vortex over Alaska. You are starting to see this show up on the long range modeling for the end of this month. 

What model ?EPS?

[LurkerBoy]

How much of a relaxation late-month?

[Isotherm]

5 hours ago, snowman19 said:

The -QBO has worked its way down to 50mb now. When you have a La Niña, HM has shown that combo works to flatten the Aleutuan ridge/high and cause downstream low heights/vortex over Alaska. You are starting to see this show up on the long range modeling for the end of this month. 

 

 

http://www.cpc.ncep.noaa.gov/data/indices/qbo.u50.index

It hasn't, unless you have daily data. The October value was still slightly positive, a slight negative trend from September.

 

[uncle W]

the QBO is very similar to 1962...1962-63 had to much blocking if there is such a thing...it's also similar to 2000...2000 had very strong blocking in December...if the ao gets as negative as forecast I believe it will again later on this year...

https://www.esrl.noaa.gov/psd/data/correlation/qbo.data

[Paragon]

7 hours ago, donsutherland1 said:

JFK: March 24-27, 2014

EWR: May 19-22, 2002

Martha's Vineyard had a low temperature of 15° on November 12. Westhampton had a low temperature of 20° on November 12. I don't have data for Toms River.

 

They seem to do better than Westhampton on radiational cooling, but KMVY's extreme lows aren't as extreme as KFOK's for some reason.  Toms River (KMJX) is the other location that does exceptionally well on nights like that.

 

 

[Paragon]

7 hours ago, donsutherland1 said:

With the AO forecast to drop to between -4.000 and -3.000 before rising toward late November and the PNA forecast to rise toward near neutral levels, it continues to appear that the second half of November will likely see readings average below normal for the period as a whole. A warmup toward the very end of the month remains possible.

Using the latest guidance, it appears that by November 20th, mean monthly temperature will fall to somewhere between 46.3° and 47.5° from yesterday’s 48.4° figure. That means November would be running between 2.0° and 3.2° below normal by that time. The implied probability for November’s finishing below normal has increased in recent days to about 68%. It is now very unlikely that autumn 2017 will become the warmest autumn on record.

That's too bad, I was hoping for a record autumn.  But we might get a record of a different kind, Don, if November does indeed end up that cold, we'll easily smash the record for the greatest change from the previous month, beating out what occurred between Dec 2015 to Jan 2016.

 

 

[CIK62]

Next 8 days averaging 45degs., or about 1 or 2 degs. BN.

Nov. needed to be +3.5degs. for a record fall to occur.   The probality is 0%, and has been for a while.  Last 10 days would need to be about +14degs. now, with the first 20 days @-2.0.

 

[PB GFI]

16 hours ago, snowman19 said:

The -QBO has worked its way down to 50mb now. When you have a La Niña, HM has shown that combo works to flatten the Aleutuan ridge/high and cause downstream low heights/vortex over Alaska. You are starting to see this show up on the long range modeling for the end of this month. 

Aaaaaand what do you think would happen if u stuck a vortex s of the Aleutians ?

Would that not pump the ridge on the west coast aaand send the trough into the east ?

The answer is see the Canadian ensembles 

Not everything is bad.

Day 13 - 15 EPS 2M are BN again , any warm ups may not hit and hold yet 

[snowman19]

19 minutes ago, PB GFI said:

Aaaaaand what do you think would happen if u stuck a vortex s of the Aleutians ?

Would that not pump the ridge on the west coast aaand send the trough into the east ?

The answer is see the Canadian ensembles 

Not everything is bad.

Day 13 - 15 EPS 2M are BN again , any warm ups may not hit and hold yet 

Not a vortex south of the Aleutians. A vortex over Alaska/+EPO

[snowman19]

11 hours ago, Isotherm said:

 

 

http://www.cpc.ncep.noaa.gov/data/indices/qbo.u50.index

It hasn't, unless you have daily data. The October value was still slightly positive, a slight negative trend from September.

 

I know 50mb was dropping and had been quickly neutralizing in October, I had read on twitter that it went negative, I have to go back and look for the tweet I saw last week 

[PB GFI]

14 minutes ago, bluewave said:

One thing is for sure. The Pacific has been in a very chaotic state recently. Just look at the positive and negative swings on the PDO and NPM since the summer. It's no wonder each of the ensemble groups are showing a different solution near day 10 and beyond.

 

 

 

 

Agree that why these are all transient to some degreee . My only point was it's more about the positions of the anomalies.

I expect a relaxation but not a long term change.

 

[PB GFI]

4 minutes ago, snowman19 said:

Not a vortex south of the Aleutians. A vortex over Alaska/+EPO

And a Vortex SW in the Aleutians with blocking over the pole is a - EPO

Just because you see ridge or vortex doesn't mean good or bad unless you context the larger set up.

 

[Ralph Wiggum]

Agree that why these are all transient to some degreee . My only point was it's more about the positions of the anomalies.

 

I expect a relaxation but not a long term change.

 

 

 

Am active in another forum having a similar discussion about the epo and the positioning of ridging etc. It's all about location location location. Take for example the nao which often has one of the more noticeable impacts on our winter weather here. If the nao is off the charts negative it is almost meaningless if the ridge/block is east-based rather than say over Baffin Island. Same goes for the epo. Cant just say such and such teleconnetion index is strong pos or strong neg so x,y,and z is going to happen downstream without actually looking at hemispheric specifics. I have also emphasized the term 'transient' in many of my recent discussions, so its funny you bring up that term here. Whether the rule this winter is transient BN temps, transient AN temps, or transient blocking is yet to be seen, but I dont think we are going to lock in to a specific pattern for weeks at a time over N America. Another poster used the term 'chaotic'....good choice of wording.

 

[Ralph Wiggum]

Just to add, I dont do a ton of SST studies but have some experience in the role of enso. I will say the moderate East based la nina couple with the unusually AN SST anomalies off of Mexico is quite the gradient in terms of SST measurements. Im quite certain this feature (strong gradient), not in and of itself, is aiding the PAC chaos scheme others have mentioned.

[Eduardo]

1 hour ago, bluewave said:

The SST configuration over the EPAC is also a first for the month of November. Those near record warm SST's off of Mexico didn't get the memo that the super El Nino ended a few years ago. This kind of SST warmth between Hawaii and Mexico is something new combined with so much cooling off South America.

 

 

 

Might this be responsible for the PAC "chaos" to which you alluded earlier?

ETA: @Ralph Wiggum great minds :-)

[Isotherm]

The increasingly strong PNJ will imprint on the troposphere in about 10 days, as the stratospheric low geopotential height anomalies downwell. However, I expect a rather potent constructive interference of w1 which will begin converging on the stratoapheric vortex as early as November 23rd. This, subsequently, will weaken the vortex by approximately 35-40% of its previous intensity. That downwelling process will occur concurrently with the resumption of base state LF forcing; together, this should yield the reemergence of both a high latitude blocking signal and Aleutian ridging by later in the first week of December or the second week. I don't expect the models to reflect that for another several days mimimum.

[SnoSki14]

The chaotic flip flopping that the models are doing is something to behold, it's been a while since I've seen such massive run to run changes from the OP runs.

[UlsterCountySnowZ]

Man the GFS sis absolutely lost on thanksgiving temps... it can’t make up its mind, back to BN after a run of warm torch 

[forkyfork]

2 hours ago, bluewave said:

It's related to the large scale pressure and wind changes over the Pacific with the record MJO. Notice how much warming has occurred there in the last month while the eastern Nino zones have cooled.

i posted about the PDO in the nina thread. i looked at every nina since 1995 and can't find such a warm la nina pacific with the exception of last year

[snowman19]

3 minutes ago, UlsterCountySnowZ said:

Man the GFS sis absolutely lost on thanksgiving temps... it can’t make up its mind, back to BN after a run of warm torch 

Yep and remember yesterday when certain people were saying how great the GFS/GEFS was? The EPS was “warm biased”? I guess the GFS is only good and superior to the Euro when it shows phantom cold, snow and blocking

[MJO812]

14 minutes ago, snowman19 said:

Yep and remember yesterday when certain people were saying how great the GFS/GEFS was? The EPS was “warm biased”? I guess the GFS is only good and superior to the Euro when it shows phantom cold, snow and blocking

Gefs is cold for Thanksgiving

[SnoSki14]

3 minutes ago, bluewave said:

This is a completely new phenomenon to have the record SST warmth north of the equator in the Eastern to Central Pacific during a La Nina. The off equator SST's are even warmer than during El Ninos before 2015-2016.

 

What do you think that will mean for the pattern, I've noticed the models are conflicted with attempting to develop SW ridging only to see it get knocked down a few days later.

[NJwx85]

2 hours ago, Snow88 said:

Gefs is cold for Thanksgiving

The GEFS has been playing catchup to the Euro all week.

The 12z GFS OP argues that some areas will approach 60 degrees on Thanksgiving. 

After a brief cool down we make an attempt at 70's on 11/27.

[NJwx85]

The cold, nasty and mostly uneventful beginning of November looks to finally be in the rear view mirror and a flip to average or even slightly above average pattern as we approach the end of November seems likely. The upcoming AO drop is significant, but the rest of the pattern supports that big cutter towards Quebec. 

[MJO812]

11 minutes ago, NJwx85 said:

The cold, nasty and mostly uneventful beginning of November looks to finally be in the rear view mirror and a flip to average or even slightly above average pattern as we approach the end of November seems likely. The upcoming AO drop is significant, but the rest of the pattern supports that big cutter towards Quebec. 

November isn't a winter month for us anyway

Let's get all the cutters now

[NJwx85]

Just now, Snow88 said:

November isn't a winter month for us anyway

Let's get all the cutters now

December isn't a Winter month for us either. January has been questionable the last few years.