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Pattern Dazzling December

NickyBGuarantee said:
At first glance it looks not great but this is air that’s still plenty cold enough to support some winter weather with the suppressed storm track and blocking over top .. and the gfs is certainly playing with that idea right now .. cold enough for a thumping of snow with a dynamic system. Still gfs is a bad model so this is just eye candy but I won’t budge on believing anything it says until CMC but more importantly the euro agrees with it
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Oh yeah I agree. Currently there are caveats we can take away from the gfs but I trust it very little especially when the ensembles have not had its back. Obviously the nice little wound up low giving the deep south snow is fun to look at.
 
The 00z GFS looks very similar to that storm we tracked last year. Marginal temps that are reliant on the SE Canada Vortex. By the way, the GFS loves to pull the setup of overamplifying a low coming from the plains a LOT. I bet if I search through the archive thread, I could find several more.

Wintry - Winter 2021/2022 Model Archive

12z GFS 11/25 Nice Overrunning event! https://southernwx.com/community/threads/december-thread-name.1009/page-7#post-483194
southernwx.com
 
Ollie Williams said:
The 00z GFS looks very similar to that storm we tracked last year. Marginal temps that are reliant on the SE Canada Vortex.

Wintry - Winter 2021/2022 Model Archive

12z GFS 11/25 Nice Overrunning event! https://southernwx.com/community/threads/december-thread-name.1009/page-7#post-483194
southernwx.com
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Yeah except it goes a lot further south than the one last year if I remember correctly. I’m surprised the snow is that far south.
 
Stevo24 said:
Yeah except it goes a lot further south than the one last year if I remember correctly. I’m surprised the snow is that far south.
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Try the 00z CMC 1/11/2022 run. This one was even closer.

Wintry - Winter 2021/2022 Model Archive

12z GFS 11/25 Nice Overrunning event! https://southernwx.com/community/threads/december-thread-name.1009/page-7#post-483194
southernwx.com
 
I think if you loop the 0z GFS, the Midwest bomb on Monday and Tuesday, stalls and goes towards the Rockies and ejects East to become the SE winter storm a few days later! Crazy, crazy run! ⛄️
 
9b4c2906842267d04cc00f98444aebc6.jpg

CMC during the gfs fantasy storm. These models are a joke


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I think it’s fair to mention that we could be dealing with a bit of a warm up for a couple days before Christmas. All 3 major ensembles are hinting at it. They do have cold air moving back in on Christmas day! Will be interesting to see what happens. Surprising the EPS is the coolest. As long as the 0z gfs doesn’t happen
d7788ac3dac45a7423bda79e47049ddc.jpg
fc03fb6514c22739f982b3beb7937b8a.jpg


895afdb84be7bd4004afe217fc02d61c.jpg



Sent from my iPhone using Tapatalk
 
I've looked at a lot of old winter storms from the past, and I can say with confidence that I've never seen one take this progression / path at 500mb that is shown on this 00z GFS run. The wave tracks from N California to Nebraska, makes a loopty-loop, extending back into Wyoming, then dives SE to Charleston. Highly unlikely to happen that way, but as the country song goes, "there's a first time for everything"

Anyway, as @ILMRoss alluded to earlier today, all of the models are struggling with this wacky, blocky pattern, not just the GFS. There's no better time than now to lean on the ensemble means...and even those aren't staying consistent

JfXlZh1.gif
 
griteater said:
I've looked at a lot of old winter storms from the past, and I can say with confidence that I've never seen one take this progression / path at 500mb that is shown on this 00z GFS run. The wave tracks from N California to Nebraska, makes a loopty-loop, extending back into Wyoming, then dives SE to Charleston. Highly unlikely to happen that way, but as the country song goes, "there's a first time for everything"

Anyway, as @ILMRoss alluded to earlier today, all of the models are struggling with this wacky, blocky pattern, not just the GFS. There's no better time than now to lean on the ensemble means...and even those aren't staying consistent

JfXlZh1.gif
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This is what I posted earlier. You can see it go back towards the Rockies, even on the surface maps!! Very bizarre
 
If worried about a warm up after this cold shot, read the CPC long range forecast discussion from earlier today. It notes the GFS is basically not very usable currently because it's improperly handling storms in relation to the -NAO/blocking pattern. That is causing it to have wildly varying results from run to run as it gets further into the extended. CPC said they aren't even using it in their longer range forecasts right now and instead are using the Euro/EPS.
 
John1122 said:
If worried about a warm up after this cold shot, read the CPC long range forecast discussion from earlier today. It notes the GFS is basically not very usable currently because it's improperly handling storms in relation to the -NAO/blocking pattern. That is causing it to have wildly varying results from run to run as it gets further into the extended. CPC said they aren't even using it in their longer range forecasts right now and instead are using the Euro/EPS.
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Thanks John. Just read thru it. A lot of times they don't add those types of interesting tidbits like they did in the old days....maybe this "Scott H" forecaster is one of the better ones to follow

Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks
NWS Climate Prediction Center College Park, MD
300 PM EST Fri December 09 2022

8-14 DAY OUTLOOK FOR DEC 17 - 23 2022

During the week-2 period, models are in good agreement in persisting a 500-hPa
ridge across Alaska, but differ as to the strength and orientation. Farther to
the east, as the GEFS significantly weakens the ridge predicted over eastern
Canada relative to today's ECMWF and Canadian Ensemble Means. The increased
model uncertainty across the higher latitudes of North America results in high
forecast spread in the predicted strength of the AO, which in turn, increases
uncertainty in the overall pattern farther to the south over the CONUS. The
ECMWF ensemble mean solution maintains the strongest ridge over Alaska, thus,
reflects a correspondingly strong trough farther to the south near California.
Meanwhile, the Canadian ensemble maintains a strong trough across the eastern
CONUS, consistent with anomalous ridging forecast near Greenland. The GEFS
depicts near normal heights over most of the CONUS, with significant below
normal heights confined to the southwestern CONUS. Today’s week-2 manual height
blend favors the 00z ECMWF Ensemble Mean solution, based on considerations of
recent skill.

The official 8-14 day 500-hPa height blend consists of: 20% of Today's 6z GFS
Ensemble Mean centered on Day 11, 55% of Today's 0z European Ensemble Mean
centered on Day 11, and 25% of Today's 0z Canadian Ensemble Mean centered on
Day 11

FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: About Average, 3 out of 5, due to
good agreement among models on an amplified pattern early in the period offset
by significantly increased model uncertainty by the end of week-2.

FORECASTER: Scott H


DfTBZZo.png
 
John1122 said:
If worried about a warm up after this cold shot, read the CPC long range forecast discussion from earlier today. It notes the GFS is basically not very usable currently because it's improperly handling storms in relation to the -NAO/blocking pattern. That is causing it to have wildly varying results from run to run as it gets further into the extended. CPC said they aren't even using it in their longer range forecasts right now and instead are using the Euro/EPS.
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Just look at the GFS here for 3 days before Christmas. It goes from average to really cold in 3 runs(!)... I mean... How can anyone take it seriously in the Christmas timeframe?

Watch the ensembles and the larger signals
 
griteater said:
Thanks John. Just read thru it. A lot of times they don't add those types of interesting tidbits like they did in the old days....maybe this "Scott H" forecaster is one of the better ones to follow

Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks
NWS Climate Prediction Center College Park, MD
300 PM EST Fri December 09 2022

8-14 DAY OUTLOOK FOR DEC 17 - 23 2022

During the week-2 period, models are in good agreement in persisting a 500-hPa
ridge across Alaska, but differ as to the strength and orientation. Farther to
the east, as the GEFS significantly weakens the ridge predicted over eastern
Canada relative to today's ECMWF and Canadian Ensemble Means. The increased
model uncertainty across the higher latitudes of North America results in high
forecast spread in the predicted strength of the AO, which in turn, increases
uncertainty in the overall pattern farther to the south over the CONUS. The
ECMWF ensemble mean solution maintains the strongest ridge over Alaska, thus,
reflects a correspondingly strong trough farther to the south near California.
Meanwhile, the Canadian ensemble maintains a strong trough across the eastern
CONUS, consistent with anomalous ridging forecast near Greenland. The GEFS
depicts near normal heights over most of the CONUS, with significant below
normal heights confined to the southwestern CONUS. Today’s week-2 manual height
blend favors the 00z ECMWF Ensemble Mean solution, based on considerations of
recent skill.

The official 8-14 day 500-hPa height blend consists of: 20% of Today's 6z GFS
Ensemble Mean centered on Day 11, 55% of Today's 0z European Ensemble Mean
centered on Day 11, and 25% of Today's 0z Canadian Ensemble Mean centered on
Day 11

FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: About Average, 3 out of 5, due to
good agreement among models on an amplified pattern early in the period offset
by significantly increased model uncertainty by the end of week-2.

FORECASTER: Scott H
Click to expand...
Give this one a try as well. It's the one that speaks about the GFS having issues and expects the cold air to continue into week 3, and that week 3 will be so BN that the week 4 will average out to BN even if there's warming in parts of the country as they expect the return of the -PNA. They note the -NAO is likely to continue, along with the -AO through the 4 week period.

Climate Prediction Center - Week 3-4 Outlook

www.cpc.ncep.noaa.gov www.cpc.ncep.noaa.gov
 
John1122 said:
Give this one a try as well. It's the one that speaks about the GFS having issues and expects the cold air to continue into week 3, and that week 3 will be so BN that the week 4 will average out to BN even if there's warming in parts of the country as they expect the return of the -PNA. They note the -NAO is likely to continue, along with the -AO through the 4 week period.

Climate Prediction Center - Week 3-4 Outlook

www.cpc.ncep.noaa.gov www.cpc.ncep.noaa.gov
Click to expand...
Thanks, good nuggets in there and well written
 
The GFS is struggling mainly with the second piece of energy coming into the US along with our first piece.

0424BF83-BE3E-41B3-AFAF-A095644179AE.jpeg

A few things I think are in play here. Mainly, the GFS is holding back our first piece JUST a bit more than the EURO. Obviously this allows for more interaction between the two. Here is the Euro.9C109144-EDFF-4EB3-84DD-8A25FA833401.png
The GFS has started to build separation back between the waves at 6z. (Does it stick?)

B91B0B0F-0E56-43FA-99E1-2BAE6F102D3F.gif

This doesn't matter a ton for this initial storm other than NW flow threat. BUT it has everything to do witch our second system and the pattern after. I guess the point I'm making is it's not surprising the GFS is all over the place given one of the elements is over the Pacific and closer to Russia at this point.
F61BBEA5-6161-438F-8F76-F38403DCFE40.jpeg
 
I gotta say the Euro and CMC keeps the cold in place and has been consistent showing that. I’m not trusting the GFS at this moment with how much flip flopping it’s doing. Look at the last 3 Euro runs compared to last 3 GFS runs for 200-240 hours out. Euro is clearly more consistent.
 
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