1/19 - The Weekend Roulette Wheel Thing

[SnowGoose69]

3 minutes ago, Heisy said:

Difference between GFS, CMC, and Euro AI at 90 hours

To give you an idea of what differences each model has.

18z rgem was in the euro Ai camp fwiw




.

The GFS/GEFS difference for the storm on the Gulf Coast last 120 could be the craziest difference I’ve seen from the Op to an ensemble on a single model run inside  day 7 ever 

[clskinsfan]

NAM has a thump on Saturday before the frontal passage. It has been showing up off and on for the past few days. 

[TSSN+]

Euro is trending weaker and weaker each run. 

[mitchnick]

3 minutes ago, TSSN+ said:

Euro is trending weaker and weaker each run. 

To think that the Gfs will prevail, which has had it as nothing of consequence all along, is a scary and sobering thought. 

[TSSN+]

Just now, mitchnick said:

To think that the Gfs, which has had it as nothing of consequence all along, will prevail is a scary and sobering thought. 

The one time it will be right lol. But it’s not over yet. 

[CAPE]

4 minutes ago, TSSN+ said:

Euro is trending weaker and weaker each run. 

I'll take it. The last few runs are all "weak". This is not going to be a significant event. A little snow before the Arctic blast is fine.

 

[mitchnick]

2 minutes ago, TSSN+ said:

The one time it will be right lol. But it’s not over yet. 

Let's hope not. 

A bit surprising how different the operational and AI have been on this. Recent events have had them pretty similar.

[WxUSAF]

I want the 0z euro run. 3-5” area wide

[DDweatherman]

4 minutes ago, WxUSAF said:

I want the 0z euro run. 3-5” area wide

It’s far from over. Maybe tonight’s 0z will hear you.

[WesternFringe]

53 minutes ago, psuhoffman said:

Not in this kind of pattern with this kind of storm.   Every time this exact same thing gets said. And someone points it out. Then we do it again 

Guess I wasn’t articulating well.  I have been reading and posting about the volatility and unpredictability of this pattern.  
 

I was just trying to say because of that we find ourselves with different lead times than we typically have with tracking.

[JenkinsJinkies]

When was the last time the first football of the season waited until late January?

[psuhoffman]

22 minutes ago, CAPE said:

I'll take it. The last few runs are all "weak". This is not going to be a significant event. A little snow before the Arctic blast is fine.

 

Depends what you think is significant. It wouldn’t take a lot to energize the boundary into a 3-5” snow event but that would also be further NW.  There is a reason the runs with more snow target 95 NW and weaker runs target SE. A more amplified wave will stall the boundary as it presses for a time and so the snow ends up NW of the weaker wave solutions that do not slow the boundary. Since the snow will end up wherever the boundary is lol. So it seems the max potential of it ends up southeast of 95 is a 1-3” snow. If it ends up NW it would likely end up a bigger event. Not by a lot but slightly more. 

[CAPE]

1 hour ago, psuhoffman said:

Depends what you think is significant. It wouldn’t take a lot to energize the boundary into a 3-5” snow event but that would also be further NW.  There is a reason the runs with more snow target 95 NW and weaker runs target SE. A more amplified wave will stall the boundary as it presses for a time and so the snow ends up NW of the weaker wave solutions that do not slow the boundary. Since the snow will end up wherever the boundary is lol. So it seems the max potential of it ends up southeast of 95 is a 1-3” snow. If it ends up NW it would likely end up a bigger event. Not by a lot but slightly more. 

This logic seems silly. This is the best Euro run of the last 4. You mean if it was a bit further SE there wouldn't be that 4"+ 'jackpot'. Come on lol. That 4-5" area easily could be a bit further NW, or SE, depending on the exact location of the boundary, sharpness of the shortwave and associated dynamics. etc.

[ChillinIt]

[wasnow215]

I can't remember a better name for a thread lol! Priceless 

[DDweatherman]

9 minutes ago, wasnow215 said:

I can't remember a better name for a thread lol! Priceless 

Thank you. The name might be all we have come this weekend.

[mitchnick]

18z AI a little drier than 12z mainly on the north side.

https://charts.ecmwf.int/products/aifs_medium-mslp-rain?base_time=202501151800&interval=6&projection=opencharts_north_america&valid_time=202501160000

[clskinsfan]

11 minutes ago, WEATHER53 said:

Sunday is full moon I think and I’ve seen enough that storms seem to amplify when it’s fulL Does  Not make something out of nothing but does turn light to moderate or moderate to heavy

 

I think the full moon was 2 days ago? 

 

[WEATHER53]

4 minutes ago, clskinsfan said:

I think the full moon was 2 days ago? 

 

Ok I just didn’t look first 

[clskinsfan]

NAM with a snow shower for DC tomorrow

[psuhoffman]

1 hour ago, CAPE said:

This logic seems silly. This is the best Euro run of the last 4. You mean if it was a bit further SE there wouldn't be that 4"+ 'jackpot'. Come on lol. That 4-5" area easily could be a bit further NW, or SE, depending on the exact location of the boundary, sharpness of the shortwave and associated dynamics. etc.

It depends because there are 2 variables here. Where the thermal boundary ends up and the amplitude of the wave. They are not 100% linked but there is some causality between the two. 
 

A more amplified wave will cause the boundary to end up further northwest.  A slightly more amplified wave would slow the progress of the boundary east. Enough amplification could even push it further nw which is what the ggem does and is why that’s an even bigger snow but NW of this whole forum. 
 

It is possible to get a bigger snow solution further southeast but to do that you need to both increase the amplitude of the wave but also adjust the thermal boundary even more southeast to compensate. So you would need two errors instead of just one. If you simply adjust the wave to be more amplified it will shift the snow northwest and increase the snowfall.  If you want to increase the snowfall AND not shift it NW you need a stronger wave  and to hope guidance is also wrong with the location of the boundary and it’s actually further east to start. 
 

I guess in my initial post I was only accounting for adjusting the amplitude of the wave when it is possible other variables could be adjusted also. 

[MDScienceTeacher]

5 hours ago, snowfan said:

If this fails, PA posters are forever banned from this sub forum. 

Is it slow up there in the Philadelphia Region ? I am seeing a lot folks coming in from up there recently.  I guess getting fringed earlier this month will make people jealous.

 

[StormyClearweather]

ICON looks better, for those who care about what the Germans think.

 

edit: 2-4 for most - I am mobile so I can’t post a map

[Jebman]

Someone needs to wager a million dollars on this roulette wheel.

[psuhoffman]

Can’t sleep damnit. 
 

Ggem is going to come SE from its ridiculous 12z inland runner idea but it’s still going to be more amplified and NW than other guidance based on rgem at 84h. Probably a hit for the NW parts of the forum. 

[Blizzard of 93]

ICON at 0z had a pretty significant move north from its 18z run.

Here’s the precip comparison.

0z top

18z bottom

[VA Mad Man]

15 minutes ago, StormyClearweather said:

ICON looks better, for those who care about what the Germans think.

 

edit: 2-4 for most - I am mobile so I can’t post a map

Was it over when the Germans bombed Pearl Harbor? Hell no! Let’s go!!

[psuhoffman]

I’m not gonna extrapolate what it means but the NAM at the end has the SW responsible for the Sunday threat all the way back in TX/OK at the same time it’s in the TN valley on other guidance. lol 

[snowdude]

11 minutes ago, VA Mad Man said:

Was it over when the Germans bombed Pearl Harbor? Hell no! Let’s go!!

Except the Germans never bombed Pearl Harbor. That would be the JMA. What does that model say? No one cares. 

[Ji]

6 minutes ago, psuhoffman said:

I’m not gonna extrapolate what it means but the NAM at the end has the SW responsible for the Sunday threat all the way back in TX/OK at the same time it’s in the TN valley on other guidance. lol 

i thought you were going to bed at 9 lol.

Whats up with this icon model? It shows snow on the 00z/12z and loses it on the 6z/18z