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Pattern January 2020 - Operation Thaw Alaska

Webberweather53 said:
View attachment 31439

The JMA’s MJO forecast has kind of been out to lunch lately and is way too amped in the central pacific and thus it takes longer for the wave to attenuate, which is why it’s showing phase 8 propagation. While I don’t think this scenario is impossible, given the forecast initialization errors and that this winter has been marred by strong/persistent +EPO (that the GEFS & EPS forecast) and that both the GEFS & ECMWF depict degeneration into phase 7, I’m skeptical of the nice -EPO JMA forecast in week 2. When the GEFS & ECMWF MJO forecasts agree (which doesn’t happen often), they’re usually correct. From multiple standpoints I’m cautious to buy into the JMA in spite of its recent string of forecast verification
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I do recall the JMA being way off in December with its amplitude but it still nailed the 500mb forecasts for Week 2. It kept wanting to spike the amplitude like the forecast above (and I mean spike it to the extreme in one day lead) when you obviously knew by looking that it was incorrect. Interesting to see if it busts hard here...still taking it with a mound of salt.


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That would explain why the JMA ensembles looks like the CFS then. Both are alone in the MJO progression right now on their RMMs.

I'll throw this out there as a possible learning experience for me. I posted the following a little earlier at AmWx but would appreciate Webb's and any others' input:

What is the Euro seeing?

giphy.gif


(I know its only the control, but that's the closest access I have to the OP)

Looking at that, I'm not really sure what the Euro sees to send it back to 5/6. Looks to me like it still favors 1/2

I know OLR isn't the only thing that goes into the MJO RMM plot calculation, but you'd think it would show more convection over the MC for that RMM plot.

giphy.gif







giphy.gif


Indian Ocean though:

giphy.gif


Some of it there even looks like to would be N of the equator late in the run.


Are the RMM plots calculated through some measurement that would split the difference between two convection locations?

Isotherm was arguing that most of it was south of the equator, and not having a substantial impact
(I think the +AAM from the W Pac convection would argue otherwise).

But a lot of that Indian Ocean convection looks south to me.
 
Jon said:
I do recall the JMA being way off in December with its amplitude but it still nailed the 500mb forecasts for Week 2. It kept wanting to spike the amplitude like the forecast above (and I mean spike it to the extreme in one day lead) when you obviously knew by looking that it was incorrect. Interesting to see if it busts hard here...still taking it with a mound of salt.


Sent from my iPhone using Tapatalk
Click to expand...

Hopefully you're onto something and nice analysis, but my experience with the JMA operational is that it generally sucks (perhaps not as bad as NAM/NAVGEM) and that the GFS and ICON are better. Even the CMC may be better. The Euro is way better. With a sucky underlying operational, I'd expect the ensemble to be sucky, too, unless the ensemble is somehow based on a newer, improved underlying JMA (doubtful since I'd think that new and improved underlying JMA would be the new operational).



Meanwhile, crickets at Weather Bell with still no JB Saturday Summary. Last week's, which emphasized that winter was getting started 1/20 and that cold would dominate then through March, is still there. I wonder why:

https://www.weatherbell.com/
 
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Webberweather53 said:
View attachment 31439

The JMA’s MJO forecast has kind of been out to lunch lately and is way too amped in the central pacific and thus it takes longer for the wave to attenuate, which is why it’s showing phase 8 propagation. While I don’t think this scenario is impossible, given the forecast initialization errors and that this winter has been marred by strong/persistent +EPO (that the GEFS & EPS forecast) and that both the GEFS & ECMWF depict degeneration into phase 7, I’m skeptical of the nice -EPO JMA forecast in week 2. When the GEFS & ECMWF MJO forecasts agree (which doesn’t happen often), they’re usually correct. From multiple standpoints I’m cautious to buy into the JMA in spite of its recent string of forecast verification
Click to expand...
So you'll take garbage models
GaWx said:
18Z Euro joins the GFS, ICON, and the NAM as looking a bit better than the 12Z. Hmmm.
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Mind showing
 
WeatherNC said:
For the 1/22 period, northern stream dominant vortmax will likely be through central MO, coastal areas need central KS as a baseline.
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I agree that It very likely won't happen, but only 100 miles separates much of the SE coast from the edge of the significant precip. on the 18Z runs and there's still ~60-72+ hours to go. What if upper features end up being 100 miles west of what the Euro and Icon have and the resultant sfc low is 100 miles further west? I realize that a further westward trend would need to get going almost immediately though.

I know it is a horrible model, but since it is agreeing with the trend of the other 18Z model runs: the 18Z NAVGEM also has a low center further west and stronger than what its 12Z had:

NAVGEM 18Z run:
1579398468270.png

NAVGEM 12Z run:

1579398537430.png

NAVGEM 18Z run from 24 hours ago
1579398704583.png
 
GaWx said:
My 2nd GIF thanks to Webb: 12Z worse than 0Z but 18Z better than 12Z and looks even better than 0Z imo as there is lower pressure further west on the 18Z..so keeping the 10% chance in my mind

View attachment 31441
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Pivotal euro doesn't have 18z. Do you have 18z euro snow map for that light clipper?
 
GaWx said:
I agree that It very likely won't happen, but only 100 miles separates much of the SE coast from the edge of the significant precip. on the 18Z runs and there's still ~60-72+ hours to go. What if upper features end up being 100 miles west of what the Euro and Icon have and the resultant sfc low is 100 miles further west? I realize that a further westward trend would need to get going almost immediately though.

I know it is a horrible model, but since it is agreeing with the trend of the other 18Z model runs: the 18Z NAVGEM also has a low center further west and stronger than what its 12Z had:

NAVGEM 18Z run:


NAVGEM 12Z run:



NAVGEM 18Z run from 24 hours ago
Click to expand...

There is zero reason to think this is suddenly going to shift into something good for us. The trough is just not showing too many signs of going nuetral or negative in time.

At the same time if I was bullseyed at 60-72 hours left to go it would certainly change that's 100% guaranteed. It doesnt mean this is gonna change in any kind of favorable way but that changes could still show up.
 
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