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Pattern Nippy November

Storm5 said:
It’s like Shane pointed out . The model uses algorithms in order to spit out a solution . You can’t just blanket a model and say it has a cold bias . There is a reason it spits out a cold solution . Now maybe there are flaws with how it comes up with those solutions but it’s not like it’s just spitting out cold to be cold


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Yup a cold bias is 5 models with the same setup and 1 model is 10 degrees colder and this happens over and over. A cold bias is a not model constantly arriving at a western ridge eastern trough solution past D5. That's a pattern flaw/bias that leads to a colder solution
 
Rain Cold said:
Haven't looked at any 12z runs, but I can probably fairly accurately predict how they look, simply based on this:

View attachment 26289
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I thought the 12z GEFS was interesting, especially after 12/1. Just entertainment, though. I am looking forward to the chance of 1 to 2 more inches of rain. I missed the heaviest accumulations on the past two events.
 
Yup:


gfs_z500_mslp_namer_65.png

gfs_z500_mslp_namer_65.png

GEFS mutes the signal a little bit in the LR, but still maintains the general pattern shape in place. Unfortunate. Hopefully, the EPS is better.
 
Rain Cold said:
Yup:


View attachment 26291

View attachment 26292

GEFS mutes the signal a little bit in the LR, but still maintains the general pattern shape in place. Unfortunate. Hopefully, the EPS is better.
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Yep. Below was the best I could find. 2014 ish. Cold -EPO, but no more -NAO. Right after this the trough goes into the west and ridging starts to poke up in the SE. Been there done that for the last 10 years. :(

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KyloG said:
By "cold bias" does that mean the pattern its modeling is correct and temp departures are being over estimated? Or is it not even getting the pattern right?
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Excellent question! There's been during the 6-10 day a tendency for too much W US ridging along with too much E US troughing thus leading to a tendency for the E US to be too cold and some of the west being too warm. In essence, a good bit of this is the SER being badly undermodeled just as was the case last winter. The Maxar met (who is very smart and knowledgeable), as you'll see below, says that is still an E US "cold bias". But on top of that there actually has also been a same day cold E US bias. Here's this Maxar met's response to me, which was a reply to my asking the same Qs you asked as I wanted to make sure I wasn't mistaken in calling having too cold a pattern in the E US a "cold bias":


"Hi Larry,
Cold bias is used to reference the model being too cold versus reality. This could be for varying reasons, including a simple miss in the pattern (arguably what we see in longer range projections). Here is an example using the current 6-10 Day maps comparison to when the period was in the 11-15 Day period (note the Southeast ridge in the more recent runs compared to troughing when in the 11-15 Day):

That said, the model has also been too cold in its same day projections (i.e. morning projection for the day of), so some bias even when the larger scale pattern is figured out.

I hope this helps. Let us know if you need anything else."
 
SnowNiner said:
Yep. Below was the best I could find. 2014 ish. Cold -EPO, but no more -NAO. Right after this the trough goes into the west and ridging starts to poke up in the SE. Been there done that for the last 10 years. :(

View attachment 26293
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Hard to get both patterns at the same time, I’d take my chance with threading the needle with the -EPO before the pattern switches since a -EPO delivers our best cold, we have done that to much this past decade, also note the STJ undercutting the ridge/split flow, this is a good pattern for a miller B winter storm setup, little bit similar to early last December if I’m not mistaken
 
Next tuesday/Wednesday the euro has a low pressure system in a favorable place for severe weather in the southeast ?prateptype_cat_ecmwf.conus.png
 
GaWx said:
Excellent question! There's been during the 6-10 day a tendency for too much W US ridging along with too much E US troughing thus leading to a tendency for the E US to be too cold and some of the west being too warm. In essence, a good bit of this is the SER being badly undermodeled just as was the case last winter. The Maxar met (who is very smart and knowledgeable), as you'll see below, says that is still an E US "cold bias". But on top of that there actually has also been a same day cold E US bias. Here's this Maxar met's response to me, which was a reply to my asking the same Qs you asked as I wanted to make sure I wasn't mistaken in calling having too cold a pattern in the E US a "cold bias":


"Hi Larry,
Cold bias is used to reference the model being too cold versus reality. This could be for varying reasons, including a simple miss in the pattern (arguably what we see in longer range projections). Here is an example using the current 6-10 Day maps comparison to when the period was in the 11-15 Day period (note the Southeast ridge in the more recent runs compared to troughing when in the 11-15 Day):

That said, the model has also been too cold in its same day projections (i.e. morning projection for the day of), so some bias even when the larger scale pattern is figured out.

I hope this helps. Let us know if you need anything else."
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Thanks for the response! That's kind of what I thought you guys meant but wanted to be sure.
 
metwannabe said:
Looks like to me the EPS has short lived warmups as the SER continues to get beat back.... still don't see any real torch anywhere, yet
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So really the opposite of what we are used to seeing, with the SER in place and the models showing it breaking down, only to be kicked along further down the road.
 
Cold MTN, NC is currently on fire. Wild fire.
 
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Unless every major model is really wrong, we're all going to be more or less a tad AN into December ... but two things: 1) models could be wrong (like when are they dead nuts on anyway?), and 2) there are potentially some good signs down the road ... so hang tough and enjoy the anticipation ... without having an aneurysm in the process of all this weather watching every 6 hours ...
 
Here's a summary of the 12Z GEFS/EPS and what it portends for the SE US from my perspective:

- Both models much colder in the 1st 5 days of Dec vs the last 5 days of Nov, when they're all (including CMC suite) clearly warmer than normal
- For the 1st 5 days of Dec. averaged out, the GEFS is colder to much colder than normal whereas the EPS is near normal
- Based on a clearly cold biased GEFS in recent weeks (largely due to too cold of a pattern) and a much closer to reality EPS, which I think has recently had only a small warm bias, my educated guess is that Nov 26-30 will average solidly warmer than normal and that Dec 1-5 will cool off a lot to the near to slightly colder than normal category averaged out, which I'd take in a heartbeat. Betting on the B to MB of the 12Z GEFS would not be a wise bet.
 
GaWx said:
Here's a summary of the 12Z GEFS/EPS and what it portends for the SE US from my perspective:

- Both models much colder in the 1st 5 days of Dec vs the last 5 days of Nov, when they're all (including CMC suite) clearly warmer than normal
- For the 1st 5 days of Dec. averaged out, the GEFS is colder to much colder than normal whereas the EPS is near normal
- Based on a clearly cold biased GEFS in recent weeks and a much closer to reality EPS, which I think has recently had only a small warm bias, my educated guess is that Nov 26-30 will average solidly warmer than normal and that Dec 1-5 will cool off a lot to the near to slightly colder than normal category averaged out, which I'd take in a heartbeat. Betting on the B to MB of the 12Z GEFS would not be a wise bet.
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Just in time for the Christmas season.
 
GaWx said:
Here's a summary of the 12Z GEFS/EPS and what it portends for the SE US from my perspective:

- Both models much colder in the 1st 5 days of Dec vs the last 5 days of Nov, when they're all (including CMC suite) clearly warmer than normal
- For the 1st 5 days of Dec. averaged out, the GEFS is colder to much colder than normal whereas the EPS is near normal
- Based on a clearly cold biased GEFS in recent weeks (largely due to too cold of a pattern) and a much closer to reality EPS, which I think has recently had only a small warm bias, my educated guess is that Nov 26-30 will average solidly warmer than normal and that Dec 1-5 will cool off a lot to the near to slightly colder than normal category averaged out, which I'd take in a heartbeat. Betting on the B to MB of the 12Z GEFS would not be a wise bet.
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GEFS FWIW has a few members with a southern slider
1575720000-Mzl2uatyW4A.png
 
12z EPS looks great for early December. -EPO, -NAO, upper level high breaks down. This is actually good! It's still holding on what I was talking about last night. We may have a shot at a winter event some point in early December.
be4f6de6ef559ca1ed098416d8301eb1.gif
 
Brick Tamland said:
Based on what?
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Decembers have been mostly warm, and we are headed into a pattern that will result in transient warmth, but as soon as that -epo erodes the NAO, it'll open the door to the SER developing. Historically, when the models hint at it's arrival, it'll stick for a week or two. We may have transient cold in there but always bet the SER will overstay it's expected time. Also if you read, the supposed nice setup near the end of December is highly subject to chance and usually we end up being warm right until after Christmas before we chill.
 
ForsythSnow said:
Decembers have been mostly warm, and we are headed into a pattern that will result in transient warmth, but as soon as that -epo erodes the NAO, it'll open the door to the SER developing. Historically, when the models hint at it's arrival, it'll stick for a week or two. We may have transient cold in there but always bet the SER will overstay it's expected time. Also if you read, the supposed nice setup near the end of December is highly subject to chance and usually we end up being warm right until after Christmas before we chill.
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FS, I was about to reply to Brick with one word ... "History" ... but felt uncomfortable replying to a question directed to you. You expanded on the "History" thought very, very well ... ;)
Phil
 
ForsythSnow said:
Decembers have been mostly warm, and we are headed into a pattern that will result in transient warmth, but as soon as that -epo erodes the NAO, it'll open the door to the SER developing. Historically, when the models hint at it's arrival, it'll stick for a week or two. We may have transient cold in there but always bet the SER will overstay it's expected time. Also if you read, the supposed nice setup near the end of December is highly subject to chance and usually we end up being warm right until after Christmas before we chill.
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Okay, but so far the models have only shown the SER showing up for a little while. Right now it has been the opposite of what we're used to, with the SER showing up on the models only to be beaten back. Maybe this December will be different. We'll see.
 
Hello what's the severe threat looking like next week before and after Thanksgiving?
 
Brick Tamland said:
Okay, but so far the models have only shown the SER showing up for a little while. Right now it has been the opposite of what we're used to, with the SER showing up on the models only to be beaten back. Maybe this December will be different. We'll see.
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SER is still there, especially around hour 180-240, more transient but looks like our average H5 pattern this past decade, SE Canada vortex, very negative -PNA, obviously can tell the MJO/convection ain’t helping this pattern out, but hey if that -EPO takes over like this shows more towards the end of the run, buckle up F07B52E1-E1A9-470D-82C4-09596AFC6C0A.jpeg
 
Myfrotho704_ said:
SER is still there, especially around hour 180-240, more transient but looks like our average H5 pattern this past decade, SE Canada vortex, very negative -PNA, obviously can tell the MJO/convection ain’t helping this pattern out, but hey if that -EPO takes over like this shows more towards the end of the run, buckle up View attachment 26301
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Agreed but I guess my point earlier was, at least right now, the SER doesn't look like it has staying power. It's there, it will be there some and yeah that's a warm look but if it's just a few days and then beat back, I'm good with that. The heat pump needs a break every now and then anyway...
 
KyloG said:
Personally prefer the GEFS as I loathe GOA ridges...EPS has a NAO and GEFS has the -EPO.

View attachment 26298
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I know it's out there and probably doesn't matter but give me the EPS please. The GEFS completely erases the -NAO. I want that to hold firm more or less through the winter to really mix things up. At the end of the run the GEFS starts poking the the SE ridge back up. Everything in the pacific needs to come about 1000 miles east. Pick your poison I guess.

1574371732680.png
 
SnowNiner said:
I know it's out there and probably doesn't matter but give me the EPS please. The GEFS completely erases the -NAO. I want that to hold firm more or less through the winter to really mix things up. At the end of the run the GEFS starts poking the the SE ridge back up. Everything in the pacific needs to come about 1000 miles east. Pick your poison I guess.

View attachment 26303
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The good thing is that we have around 3-5 week to play with and see how things trend. I like how things are progressing.


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This is definitely kinda of like picking your poison or drug, if you choose the gefs with the -EPO, yes, you may get get a better chance of a winter storm while it happens, and lots of cold, but once it breaks down, you get a ugly ugly pattern with a -PNA and a big southeast ridge, like last year, if you chose a -NAO to last, you are more likely gonna see more seasonal conditions with likely no winter weather, because the pacific pattern will remain a dumpster fire, but if you can get a -NAO to last on and start throwing some better things in the mix as time progresses, then things get interesting, so if your a person that’s super impatient, and want to see another early shot at some winter weather, you chose the -EPO the gefs shows, if your going for a better pattern at a more longer term, you want the -NAO to stay
 
Myfrotho704_ said:
This is definitely kinda of like picking your poison or drug, if you choose the gefs with the -EPO, yes, you may get get a better chance of a winter storm while it happens, and lots of cold, but once it breaks down, you get a ugly ugly pattern with a -PNA and a big southeast ridge, like last year, if you chose a -NAO to last, you are more likely gonna see more seasonal conditions with likely no winter weather, because the pacific pattern will remain a dumpster fire, but if you can get a -NAO to last on and start throwing some better things in the mix as time progresses, then things get interesting, so if your a person that’s super impatient, and want to see another early shot at some winter weather, you chose the -EPO the gefs shows, if your going for a better pattern at a more longer term, you want the -NAO to stay
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... and pray to high heaven for a 10 year miracle ...
 
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