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Pattern Magnificent March

Jon said:
Did you clear your cache Larry? Ens mean is almost -5 here...
044bb67a018bae9d9eccc6c7d70ecd46.jpg


Here’s 00z GEFS from NOAA, -4
6532dbbdb38c6d048ad85b5a7eebe2e6.jpg


And weatherbell 00z GEFS....
32049a3420063c09b4b54e3e7e297688.jpg
Click to expand...

I was talking about this:

IMG_2565.GIF
 

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It's fun to watch all the planetary waves in the Western Hemisphere and North Pacific retrograde as this high latitude block initially over Scandinavia goes to Greenland and eventually northern Canada. The trough over the west coast and ridging in the NE Pacific retrograde in the longer term and every cyclone over the North Atlantic occludes west of its predecessor, eventually we are gonna get a big cyclone near the eastern seaboard. This means the PNA will eventually go to neutral of even positive as the entire height field retrogrades west in response to this block
GaWx said:
I was talking about this:

View attachment 4073
Click to expand...
In no way, shape, or form is this negative NAO within 1 sigma of normal as that image shows when both the high latitude blocking high over Greenland and corresponding trough south of Atlantic Canada have height anomalies >1-1.5 sigma. Coarse ensemble mean guidance will dampen extreme blocking regimes like this that's why both the Euro and GFS op are off the charts negative
IMG_1011.PNG
 
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GaWx said:
I was talking about this:

View attachment 4073
Click to expand...

It’s because of how those are generated,
“The indices are standardized by standard deviation of the observed monthly NAO index from 1950-2000 interpolated to the day in question. A 3-day running mean is applied to the forecast time series.”

That’s likely causing the anomalies not to be as negative/strong. Probably because of the 3-day running mean if anything, but also due to the years I’m sure, as the imagine I posted above uses 1985-2012. I assume weatherbell uses something similar.


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Webberweather53 said:
It's fun to watch all the planetary waves in the Western Hemisphere and North Pacific retrograde as this high latitude block initially over Scandinavia goes to Greenland and eventually northern Canada. The trough over the west coast and ridging in the NE Pacific retrograde in the longer term and every cyclone over the North Atlantic occludes west of its predecessor, eventually we are gonna get a big cyclone near the eastern seaboard. This means the PNA will eventually go to neutral of even positive as the entire height field retrogrades west in response to this block

View attachment 4077
Click to expand...

Yeah it truly is amazing to watch and it’s crazy how similar it is to 1962 and how the -NAO disrupted the pattern in the same fashion.

Hold on to your butts.

Grr...gif is too big to display, lol.
Code: 
 https://m.imgur.com/a/bn3lA


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Kylo said:
This is CPC MRF model which not sure what that contains or is based on.
Click to expand...

That is the GEFS mean based NAO 14 day forecast, which is the one we follow the most closely and jibes with the daily NAO index that we all follow. Since 1950, the most negative single day NAO has only been down to -3.254 (10/21/2002). There have been only 5 days since 1950 with the NAO below -3:

-3.254 10/21/2002
-3.095 7/14/1962
-3.048 10/20/2002
-3.022 10/22/2002
-3.004 7/13/1962

I'm not at all saying there's not a good possibility of a very strong -NAO coming up. I think there is. But let's be realistic. A very strong -NAO is somewhere in the -2 to low -3 range. The posted GFS charts' prediction of several days of -4 to -5 is what I'm not at all buying, especially when taking into account what I posted, which is what we always follow, the daily NCEP GEFS based forecast out 14 days. No single member even gets below -2 on any one day. So, do you really think we're going to have several days of sub -4 NAO?

So, here is my prediction: there will be a strong -NAO event that may or may not lead to a cold SE. (I'm leaning toward a cold period in early March but that's not what I'm currently debating.) But the daily index that has been followed for many years on wx boards will not get anywhere near as negative as -4 to -5. I predict it won't get below -2.5. I'll follow this closely and follow up with the verification after the NAO peaks. This is what has always been used and what I'll use for verification:

ftp://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.nao.index.b500101.current.ascii

Does anyone want to bet on the NAO peaking more negative than -3.5, which would be a record breaker? If so, please reply to this and let me know. Don't be afraid. Better yet, if anyone wants to bet it will be -4 to -5, please indicate that here. I say strong -NAO but not below -2.5.
 
GaWx said:
That is the GEFS mean based NAO 14 day forecast, which is the one we follow the most closely and jibes with the daily NAO index that we all follow. Since 1950, the most negative single day NAO has only been down to -3.254 (10/21/2002). There have been only 5 days since 1950 with the NAO below -3:

-3.254 10/21/2002
-3.095 7/14/1962
-3.048 10/20/2002
-3.022 10/22/2002
-3.004 7/13/1962

I'm not at all saying there's not a good possibility of a very strong -NAO coming up. I think there is. But let's be realistic. A very strong -NAO is somewhere in the -2 to low -3 range. The posted GFS charts' prediction of several days of -4 to -5 is what I'm not at all buying, especially when taking into account what I posted, which is what we always follow, the daily NCEP GEFS based forecast out 14 days. No single member even gets below -2 on any one day. So, do you really think we're going to have several days of sub -4 NAO?

So, here is my prediction: there will be a strong -NAO event that may or may not lead to a cold SE. (I'm leaning toward a cold period in early March but that's not what I'm currently debating.) But the daily index that has been followed for many years on wx boards will not get anywhere near as negative as -4 to -5. I predict it won't get below -2.5. I'll follow this closely and follow up with the verification after the NAO peaks. This is what has always been used and what I'll use for verification:

ftp://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.nao.index.b500101.current.ascii

Does anyone want to bet on the NAO peaking more negative than -3.5, which would be a record breaker? If so, please reply to this and let me know. Don't be afraid. Better yet, if anyone wants to bet it will be -4 to -5, please indicate that here. I say strong -NAO but not below -2.5.
Click to expand...

Sounds good.

If weatherbell or weathermodels use a different method to calculate it doesn’t matter. Like you stated a strong -NAO on CPC site is -2 or -3 or lower seems reasonable. It’s all pointing to a strong -NAO.
 
GaWx said:
That is the GEFS mean based NAO 14 day forecast, which is the one we follow the most closely and jibes with the daily NAO index that we all follow. Since 1950, the most negative single day NAO has only been down to -3.254 (10/21/2002). There have been only 5 days since 1950 with the NAO below -3:

-3.254 10/21/2002
-3.095 7/14/1962
-3.048 10/20/2002
-3.022 10/22/2002
-3.004 7/13/1962

I'm not at all saying there's not a good possibility of a very strong -NAO coming up. I think there is. But let's be realistic. A very strong -NAO is somewhere in the -2 to low -3 range. The posted GFS charts' prediction of several days of -4 to -5 is what I'm not at all buying, especially when taking into account what I posted, which is what we always follow, the daily NCEP GEFS based forecast out 14 days. No single member even gets below -2 on any one day. So, do you really think we're going to have several days of sub -4 NAO?

So, here is my prediction: there will be a strong -NAO event that may or may not lead to a cold SE. (I'm leaning toward a cold period in early March but that's not what I'm currently debating.) But the daily index that has been followed for many years on wx boards will not get anywhere near as negative as -4 to -5. I predict it won't get below -2.5. I'll follow this closely and follow up with the verification after the NAO peaks. This is what has always been used and what I'll use for verification:

ftp://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.nao.index.b500101.current.ascii

Does anyone want to bet on the NAO peaking more negative than -3.5, which would be a record breaker? If so, please reply to this and let me know. Don't be afraid. Better yet, if anyone wants to bet it will be -4 to -5, please indicate that here. I say strong -NAO but not below -2.5.
Click to expand...

The weatherbell -4 isn’t the same as your -4, it’s probably closer to your -2. Again, it all depends on methodology in generating the anomalies and there seems to me multi day means and “smoothing” to the method you choose to follow, which makes it not as anomalous. The fact that -3 is that anomalous in the method you follow shows that. Either way, we’re talking about the same thing here.

A deeply negative NAO is coming, no matter what you use

6d270251b9d2790bd99183a0cb3963b2.jpg



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Kylo said:
Sounds good.

If weatherbell or weathermodels use a different method to calculate it doesn’t matter. Like you stated a strong -NAO on CPC site is -2 or -3 or lower seems reasonable. It’s all pointing to a strong -NAO.
Click to expand...

Excellent post! You made my point better/more succinctly than I did. That's what I think is going on. For whatever reason, the posted alternative sources to the traditional NCEP GEFS graphs that have been followed forever on wx forums are not an apples to apples to comparison. We're not about to get a -4 to -5 NAO based on the index we all have followed for many years.
 
Jon said:
The weatherbell -4 isn’t the same as your -4, it’s probably closer to your -2. Again, it all depends on methodology in generating the anomalies and there seems to me multi day means and “smoothing” to the method you choose to follow, which makes it not as anomalous. The fact that -3 is that anomalous in the method you follow shows that. Either way, we’re talking about the same thing here.

A deeply negative NAO is coming, no matter what you use

6d270251b9d2790bd99183a0cb3963b2.jpg
Click to expand...

Excellent post. It appears we're all on the same page more or less though I do still wonder about WxBell. Remember those WxBell graphs that predicted the near alltime record -EPO around Xmas of sub -400 to nearly -500 that I got so excited about and kept posting about? It never got anywhere close. It ended up just a run of the mill -EPO with a dip down only to -183.83 on 12/22/17:


ftp://ftp.cdc.noaa.gov/Public/gbates/teleconn/epo.reanalysis.t10trunc.1948-present.txt

I learned from that to be way more cautious about WxBell and other alternative sources. Much of that miss was due to the models way overdoing that -EPO (the Alaskan ridge never got even close to what the models showed for then), but I still have to wonder about WxBell's methodology.
 
Jon said:
The weatherbell -4 isn’t the same as your -4, it’s probably closer to your -2. Again, it all depends on methodology in generating the anomalies and there seems to me multi day means and “smoothing” to the method you choose to follow, which makes it not as anomalous. The fact that -3 is that anomalous in the method you follow shows that. Either way, we’re talking about the same thing here.

A deeply negative NAO is coming, no matter what you use

6d270251b9d2790bd99183a0cb3963b2.jpg



Sent from my iPhone using Tapatalk
Click to expand...
The smoothing plus using a base period with more frequent +NAO regimes after the late 1970s (& is honestly more relevant to our bgd climate state) is somewhat to blame although the shorter base period wxbell and NOAA ESRL uses implies larger standard deviations which makes it more difficult to attain larger standardized anomalies
 
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ForsythSnow said:
Happy hour doesn't disappoint.
gfs_mslp_pcpn_frzn_us_49.png
gfs_T850_us_50.png
Click to expand...
GOOOO Larry!
Fantasy land, but so was his 1st this year ... Damn if he could only score twice this year ... who more deserves it?
After all, he's rooted everyone else on ...
:cool:
 
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B05611F4-AD44-46D2-B779-900C55B6FD70.png
GaWx said:
That is the GEFS mean based NAO 14 day forecast, which is the one we follow the most closely and jibes with the daily NAO index that we all follow. Since 1950, the most negative single day NAO has only been down to -3.254 (10/21/2002). There have been only 5 days since 1950 with the NAO below -3:

-3.254 10/21/2002
-3.095 7/14/1962
-3.048 10/20/2002
-3.022 10/22/2002
-3.004 7/13/1962

I'm not at all saying there's not a good possibility of a very strong -NAO coming up. I think there is. But let's be realistic. A very strong -NAO is somewhere in the -2 to low -3 range. The posted GFS charts' prediction of several days of -4 to -5 is what I'm not at all buying, especially when taking into account what I posted, which is what we always follow, the daily NCEP GEFS based forecast out 14 days. No single member even gets below -2 on any one day. So, do you really think we're going to have several days of sub -4 NAO?

So, here is my prediction: there will be a strong -NAO event that may or may not lead to a cold SE. (I'm leaning toward a cold period in early March but that's not what I'm currently debating.) But the daily index that has been followed for many years on wx boards will not get anywhere near as negative as -4 to -5. I predict it won't get below -2.5. I'll follow this closely and follow up with the verification after the NAO peaks. This is what has always been used and what I'll use for verification:

ftp://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.nao.index.b500101.current.ascii

Does anyone want to bet on the NAO peaking more negative than -3.5, which would be a record breaker? If so, please reply to this and let me know. Don't be afraid. Better yet, if anyone wants to bet it will be -4 to -5, please indicate that here. I say strong -NAO but not below -2.5.
Click to expand...
I’ll take that bet! And roll with this guy....
 
The Canadian model has gotten red hot of late, almost beating the European in the medium range. The GFS on the other hand is pure garbage and had the largest drop out of all the models the last 30 days.
DWX8_MNVoAAMC5D.jpg-large.jpg
 
deltadog03 said:
I think if we get some blocking and we actually get out of phase 8 there might be a 2 week period or so of March where we can throw a Hail Mary.
Click to expand...

It would have to be a ULL. Lots of places and people who have already punted winter. Should be more snow for the rest of us.
 
Here's today's NCEP GEFS NAO update: mean going for an initial dip to between -1 and -2 around 3/1/18, a solid -NAO with individual members as low as -2:

IMG_2566.GIF
 
Per 12Z GFS, the SE finally gets a day that isn't warmer than normal on 3/1 (NC) or 3/2 (most others)! Celebration time!
 
Day 10 trends has GEFS really driving the NAO block further south and west. -EPO getting stronger.

gfs-ens_z500trend_namer_21.png
 
GaWx said:
Per 12Z GFS, the SE finally gets a day that isn't warmer than normal on 3/1 (NC) or 3/2 (most others)! Celebration time!
Click to expand...

Having one of those today. Sitting at 46 currently. Probably be the last one this week. runing +4 for the month of FEB
 
ForsythSnow said:
Sounds like we aren't spending time in phases 8-2, which likely means less favorability for cold air.
Click to expand...

We are spending time in those phases as we speak and I'm saying the -NAO will help push the MJO right along into phase 2-3. The OLR, upper level circulation anomalies, and lower-level zonal winds are clearly in the Eastern Pacific-Western Hemisphere (phase 8) right now. The plethora of southwestern Pacific TCs, rossby wave breaking in the East Pacific and sudden stratospheric warming have held the MJO back in phase 7 and projected onto U200 EOFs.
wh04.orig.component.png

The upward branch of the MJO's upper level circulation is centered over South America & Africa (Phase 8-1)
28.gif
 
Webberweather53 said:
We are spending time in those phases as we speak and I'm saying the -NAO will help push the MJO right along into phase 2-3. The OLR, upper level circulation anomalies, and lower-level zonal winds are clearly in the Eastern Pacific-Western Hemisphere (phase 8) right now. The plethora of southwestern Pacific TCs, rossby wave breaking in the East Pacific and sudden stratospheric warming have held the MJO back in phase 7 and projected onto U200 EOFs.
View attachment 4090

The upward branch of the MJO's upper level circulation is centered over South America & Africa (Phase 8-1)
View attachment 4091
Click to expand...
We never thought MJO was going to spend 30 days in phase 7. Just cause models show it blasting through 8,1,2 into 3, doesn’t mean it will!
 
The 12Z EPS is quite a bit colder than the prior run in the SE 3/3-5 with colder than normal vs the prior run's near normal to warmer than normal 3/3-5. Keep in mind that the EPS is warm biased, especially that far out.
 
As GaWx posted above the EPS was quite a run for the first week of March. -EPO really gets going to couple with the NAO.
B191C38C-ED15-4527-BD51-481910DD6453.png
 
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