January 24-26: Miracle or Mirage Thread 2

[Maestrobjwa]

15 minutes ago, Paleocene said:

NAM is always amped, that's what the A stands for. 

NAMped? 

[Nomz]

As the LWX AFD mentioned, I'd use the 10:1 instead of the Kuchera for now. Even though most of the initial thump will have good ratios, towards the end, it'll get closer to the gray area, probably leading to somewhat wetter snow and smaller ratios.

[jayyy]

When are the next runs? (Not the NAM, I don’t look at anything other than the 3k inside 48hrs)

[hstorm]

13 minutes ago, Nomz said:

As the LWX AFD mentioned, I'd use the 10:1 instead of the Kuchera for now. Even though most of the initial thump will have good ratios, towards the end, it'll get closer to the gray area, probably leading to somewhat wetter snow and smaller ratios.

To be fair, I am not sure that’s what the AFD says. It says ratios start at 15-18:1 and trend down to 7-10:1 over the storm. Depending on the initial thump that could well average out to higher than 10:1 over the full storm. In theory, Kuchera should capture this but we all know that it is far from perfect. 

[mitchnick]

10 minutes ago, Nomz said:

As the LWX AFD mentioned, I'd use the 10:1 instead of the Kuchera for now. Even though most of the initial thump will have good ratios, towards the end, it'll get closer to the gray area, probably leading to somewhat wetter snow and smaller ratios.

Probably not wet due to low temps from 850mb down. More likely rimed or mini snowballs until the warm layer is deep enough to completely melt the flakes and then fall as sleet imho.

[adelphi_sky]

Just now, mitchnick said:

Probably not wet due to low temps from 850mb down. More likely rimed or mini snowballs until the warm layer is deep enough to completely melt the flakes and then fall as sleet imho.

Haven't the models recently been underplaying cold the past few weeks? Or have they been generally accurate. I recall convos about forecasts busting low. Are we expecting the models to have the temps correct on the high side for this storm for mixing? Even if there is a warm nose. Could that be accurate? Or would it be something that could only be determined at game time?

[LP08]

Through 24hr, better cold push over the east on the NAM.

[bncho]

5 minutes ago, hstorm said:

To be fair, I am not sure that’s what the AFD says. It says ratios start at 15-18:1 and trend down to 7-10:1 over the storm. Depending on the initial thump that could well average out to higher than 10:1 over the full storm. In theory, Kuchera should capture this but we all know that it is far from perfect. 

Looking over Kuchera it looks like the average GFS ratio is ~14:1 while the average Euro ratio will be ~13:1 (for DC, Balt) Take from that what you will, but I would say that's a decent estimate, if anything a little bit high.

[LVblizzard]

1 minute ago, LP08 said:

Through 24hr, better cold push over the east on the NAM.

12z HRRR had the same thing.

[mitchnick]

1 minute ago, adelphi_sky said:

Haven't the models recently been underplaying cold the past few weeks? Or have they been generally accurate. I recall convos about forecasts busting low. Are we expecting the models to have the temps correct on the high side for this storm for mixing? Even if there is a warm nose. Could that be accurate? Or would it be something that could only be determined at game time?

In the overall pattern, they have been in the long range. But I don't know if that applies in the short range....probably not, since each storm is different with its unique conditions. 

[Ralph Wiggum]

Just now, LVblizzard said:

12z HRRR had the same thing.

2 extremely trustworthy models at range.

[Weather Will]

WB 9Z SREF thru 7pm Sunday

[TSSN+]

4 minutes ago, Ralph Wiggum said:

2 extremely trustworthy models at range.

Wish they would turn off the Nam already so we can stop extrapolating it out to 243855 hours 

[TSSN+]

1 minute ago, Weather Will said:

WB 9Z SREF thru 7pm Sunday

F it im in. I hate the srefs but I’ll hug that. Lol

[SnowenOutThere]

Interestingly the 12z NAM looks very similar to its 0z run so far as it has the same NS setup. For those who don't remember the 0z run looked to be very good for us all. 

[mob1]

Since what we're looking for out west seems to allude most people, I'll at least mention that confluence is notably better in the east at hour 36 than last run (heights are lower). 

[adelphi_sky]

2 minutes ago, TSSN+ said:

F it im in. I hate the srefs but I’ll hug that. Lol

I'm getting dizzy. Some models have a n/s orientation of the snow and others like this have an e/w orientation. Assume the n/s models have a low off the cost and the e/w have just overrunning? 

[87storms]

4 minutes ago, Weather Will said:

WB 9Z SREF thru 7pm Sunday

Seems a little odd to have lower totals west of dc. Dulles will do better than college park in this type of setup.

[psuhoffman]

1 hour ago, mitchnick said:

6z Ukie ensembles convinced they were too warm.

It’s been several years so I’m not sure if this is still true but I know at one point t the UK ensembles were counting ice as snow which inflated their output. That kinda looks like it still does. 

[Solution Man]

Just now, mob1 said:

Since what we're looking for out west seems to allude most people, I'll at least mention that confluence is notably better in the east at hour 36 than last run (heights are lower). 

That’s about as far I will consider trusting on that model….36 hours

[jwLwx]

SIAP...

 

[LP08]

1 minute ago, adelphi_sky said:

I'm getting dizzy. Some models have a n/s orientation of the snow and others like this have an e/w orientation. Assume the n/s models have a low off the cost and the e/w have just overrunning? 

We can't make fun of the NAM then post the 87 HR SREFs.  Both our terrible and outside there "usefull range".  Both the 12k and 3k have a small but noticeable cold push over the east through 36.  Thats all I am looking for.

[mob1]

Just now, Solution Man said:

That’s about as far I will consider trusting on that model….36 hours

Pretty much. After that it's a timing thing, if the phase out west comes together quickly, heights will quickly rise. 

Do many variables here, it's simultaneously frustrating and fascinating to track. 

[Buddy1987]

1 minute ago, LP08 said:

We can't make fun of the NAM then post the 87 HR SREFs.  Both our terrible and outside there "usefull range".  Both the 12k and 3k have a small but noticeable cold push over the east through 36.  Thats all I am looking for.

Great post! Can see that 50/50 is trying to work it's magic here. Any amount helps to lock things in.

[LVblizzard]

The phase looks like it will happen a bit later on this run. Both the northern and southern streams are hanging back a bit more.

[yoda]

12z NAM h5 45

 

[mob1]

Early changes on the NAM seem positive, let's see what it shows on the surface in a few frames. 

[yoda]

12z NAM h5 48

 

06z NAM h5 54

 

[Weather Will]

NAM must run off a 1970 computer, it is so slow....

[bncho]

NAM heights are a little bit lower than 6z, and the Canadian HP is 1047 instead of 1045