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Pattern Jammin January 2024

Snowfan said:
gfs_mslp_pcpn_frzn_us_33.png
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Annnnnd completely disappeared. A few frames later.
 
I love how all this talk has been about mid to late January.. we’re getting threats in mid to late January in a strong El Niño winter that is known for its February cold patterns across the US. Should be good news for things down the line for everyone!

Anywho.. I’ll take the 00z UKMET for southern Illinois on Sunday-Monday please! IMG_3005.jpeg
 
Well yall...I feel like the UKIE is showing my thoughts on this pattern. I think the system yall are thinking (the thread is open on it) gets some of yall snow, but I feel like the BEST shot for a board wide hit is from the final energy in the pattern...see the map....


IDEA THOUGHTS ON PATTERN THUR AFT.png
 
Iceagewhereartthou said:
If this is the case then why would they use it for the base for the EPS runs? Doesn't that mean the EPS runs are based on a crappy low resolution solution? Why would we ever put any stock in the EPS?
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I think it's a computing power issue. It seems to take forever to get the operational output. If you took the operationals at their current resolution and reran them many times over, it would probably take a very long time. So what is done is that they rerun the operational at a lower resolution for the entirety of the time scale. Then they perturb the initial conditions as many times as a particular suite calls for (for the Euro, that would be 50 times - hence 50 individual ensemble members, based off of a control run with 50 slight initial condition variations).

I think we, in the weather forum and social media world, quite often see a failure to use the ensembles for the purpose for which they are intended. For instance, they could be used to validate 7-10 day pattern that might be conducive to a winter storm. Conversely, they are not intended to nail down the specifics of a 7-10 day snowstorm. They are also not intended to be used on an individual member basis. So, when you see a Euro operational model not showing a D7 threat but the Euro control is showing a D7 snowstorm, your point is quite valid: Why would we believe a control run with only one eye looking through a milk jug over an operational run with two eyes with scratched up glasses with the wrong prescription? Answer? We shouldn't. Is it fun to look at? Yes. Is it worth anything, not really (when used like that).

We could have a lengthy discussion about use cases for ensembles. But professionals generally use them to determine the uncertainty around short term specific events (storm formation, rainfall totals, etc.) and the validity of medium and longer range patterns. If the ensembles generally agree with the operational, then you can have higher confidence.

When it comes to winter storms threats, IMO (and others may feel differently), but you should not look at an individual ensemble member to validate anything at all, i.e. the Euro control. However, there is value in observing trends and run to run changes. There is value in observing how many ensemble members are showing a system vs. not (and a note here, as we have all seen, a few big members can skew the mean, so looking at the mean by itself may not be all that valuable in some instances).

Everything gets less skilled out in time, particularly the lowest-skilled solutions like individual ensemble members. Use the ENS to validate the OP and the individual members to see if there are wild or minor differences among members, which will give you an indication of how volatile the atmosphere is. Ensembles are best used to detect the level of uncertainty. Use them against themselves and against other ensemble suites for that purpose.
 
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Rain Cold said:
I think it's a computing power issue. It seems to take forever to get the operational output. If you took the operationals at their current resolution and reran them many times over, it would probably take a very long time. So what is done is that they rerun the operational at a lower resolution for the entirety of the time scale. Then they perturb the initial conditions as many times as a particular suite calls for (for the Euro, that would be 50 times - hence 50 individual ensemble members, based off of a control run with 50 slight initial condition variations).

I think we, in the weather forum and social media world, quite often see a failure to use the ensembles for the purpose for which they are intended. For instance, they could be used to validate 7-10 day pattern that might be conducive to a winter storm. Conversely, they are not intended to nail down the specifics of a 7-10 day snowstorm. They are also not intended to be used on an individual member basis. So, when you see a Euro operational model not showing a D7 threat but the Euro control is showing a D7 snowstorm, your point is quite valid: Why would we believe a control run with only one eye looking through a milk jug over an operational run with two eyes with scratched up glasses with the wrong prescription? Answer? We shouldn't. Is it fun to look at? Yes. Is it worth anything, not really (when used like that).

We could have a lengthy discussion about use cases for ensembles. But professionals generally use them to determine the uncertainty around short term specific events (storm formation, rainfall totals, etc.) and the validity of medium and longer range patterns. If the ensembles generally agree with the operational, then you can have higher confidence.

When it comes to winter storms threats, IMO (and others may feel differently), but you should not look at an individual ensemble member to validate anything at all, i.e. the Euro control. However, there is value in observing trends and run to run changes. There is value in observing how many ensemble members are showing a system vs. not (and a note here, as we have all seen, a few big members can skew the mean, so looking at the mean by itself may not be all that valuable in some instances).

Everything gets less skilled out in time, particularly the lowest-skilled solutions like individual ensemble members. Use the ENS to validate the OP and the individual members to see if there are wild or minor differences among members, which will give you an indication of how volatile the atmosphere is. Ensembles are best used to detect the level of uncertainty. Use them against themselves and against other ensemble suites for that purpose.
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In regards to the Euro Control run in this current situation, I think I may partly disagree. I'll offer this up for consideration:

Screenshot_2024-01-11_at_11.12.19_AM.png

Credit to Allan, as I will confess I was not aware of this information.
 
1300m said:
In regards to the Euro Control run in this current situation, I think I may partly disagree. I'll offer this up for consideration:

View attachment 141446

Credit to Allan, as I will confess I was not aware of this information.
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I didn't know that either. I guess my question would be, why would a control replace the operational? Usually they beta test a potential replacement. I know the ensembles are built off of the lower resolution control, so I'm not sure how that factors into what Allan posted. Idk
 
Rain Cold said:
I didn't know that either. I guess my question would be, why would a control replace the operational? Usually they beta test a potential replacement. I know the ensembles are built off of the lower resolution control, so I'm not sure how that factors into what Allan posted. Idk
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Essentially the control should be your base model run. EPS should handle the range of variability within that one run. Or am I out of my element here?
 
digging on the ecmwf website I cannot find it but probably not looking in the right places :)
 
Personally I don’t like the 3 run eps trend of continuing to shear out and shift the light snow south. Just continues to harp on the idea that maybe we get too much cold air and suppression to the point where we are not allowing a storm or wave to materialize to an extent we need it to.

Still time to track this and for things to shake out differently.. it is the driest outlier of all the models so we will see.. almost getting within short range models now though..
 
NickyBGuarantee said:
Personally I don’t like the 3 run eps trend of continuing to shear out and shift the light snow south. Just continues to harp on the idea that maybe we get too much cold air and suppression to the point where we are not allowing a storm or wave to materialize to an extent we need it to.

Still time to track this and for things to shake out differently.. it is the driest outlier of all the models so we will see.. almost getting within short range models now though..
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You really feel we'll get this much suppression next week? Awful lot on that 12z run
 
Regarding the Op vs. Control, this is from a paper on Ensembles. It says that the Op (high resolution) is better than the Control (low resolution) from days 1-5, and the Control is better than the Op from days 6-11....and both are better than the ensemble members. I suppose the high resolution presents additional issues as you go out in time

18HVPs4.png


f3nMuM4.png
 
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