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Post by Snowstorm920 on Jan 22, 2023 21:03:13 GMT -6
3km NAM looks really good as well
A tick or two SE of the 12km NAM
Also looks like it has some hints of convention in the deformation zone. Might have to dig into the soundings
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Post by amstilost on Jan 22, 2023 21:04:21 GMT -6
I notice that the NAM 3km model has a little less qpf and a little less snow at 60hrs vs the NAM but the placement is almost identical all the way back to TX. Even with the tick north in the upper features the snow placement still seems like it should nudge north more.
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Post by amstilost on Jan 22, 2023 21:05:30 GMT -6
Damn you 920  |
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Post by landscaper on Jan 22, 2023 21:07:18 GMT -6
I agree with World Series, if the GEM and RGEM start coming in better and closer to that solution I will think more of it, we could very easily wake up tomorrow only to see the 6z GFS/NAM go towards the much more toned down solutions that are out there. I still like the 3-7” for the metro, and 4-8” just south and southwest of the metro . I’m just not ready to go all in on the 7-10” NAM solution
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Post by cardsnweather on Jan 22, 2023 21:07:43 GMT -6
RGEM ticks N as well. And is way more bullish QPF wise. Good start to 00z
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Post by bdgwx on Jan 22, 2023 21:08:12 GMT -6
NAM is way north. Part of the reason why dynamic model guidance is showing the axis of heavy snow so close to the 850mb low is because the temperatures at that level is colder than the GYB benchmark. In addition to the 90 nm rule (which is only probabilistic) Browne & Younkin 1970 also say the axis of heaviest snow is centered on the 850mb -5 C isotherm which is what the NAM is showing. Statistical approaches like GYB are incredibly powerful, but I don't think you can ignore dynamical guidance either. If it's one thing I've learned watching our events play out is that trying to outsmart dynamic model guidance is risky.
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Post by ajd446 on Jan 22, 2023 21:08:28 GMT -6
Rgem, is trending nw a bit too, not to the nam, but a subtle trend
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Post by Worldserieschampions (Chicago) on Jan 22, 2023 21:10:24 GMT -6
RGEM ticks N as well. And is way more bullish QPF wise. Good start to 00z At the surface, the nam is much further north. Haven’t dug into upper levels, but there appears to be big disparities in outcomes. |
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Post by cardsnweather on Jan 22, 2023 21:12:45 GMT -6
NAM is way north. Part of the reason why dynamic model guidance is showing the axis of heavy snow so close to the 850mb low is because the temperatures at that level is colder than the GYB benchmark. In addition to the 90 nm rule (which is only probabilistic) Browne & Younkin 1970 also say the axis of heaviest snow is centered on the 850mb -5 C isotherm which is what the NAM is showing. Statistical approaches like GYB are incredibly powerful, but I don't think you can ignore dynamical guidance either. If it's one thing I've learned watching our events play out is that trying to outsmart dynamic model guidance is risky. And -6 to -8 when looking at 700mb, correct? Could be splitting hairs but I think 10-15 miles SW of Stl and 10-15 miles on either side would be best guess at heaviest band. |
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Post by TK on Jan 22, 2023 21:13:46 GMT -6
I won't get any hopes up until Uncle Ukie has his say....
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Post by Worldserieschampions (Chicago) on Jan 22, 2023 21:14:04 GMT -6
NAM is way north. Part of the reason why dynamic model guidance is showing the axis of heavy snow so close to the 850mb low is because the temperatures at that level is colder than the GYB benchmark. In addition to the 90 nm rule (which is only probabilistic) Browne & Younkin 1970 also say the axis of heaviest snow is centered on the 850mb -5 C isotherm which is what the NAM is showing. Statistical approaches like GYB are incredibly powerful, but I don't think you can ignore dynamical guidance either. If it's one thing I've learned watching our events play out is that trying to outsmart dynamic model guidance is risky. This sounds like something chatGPT would say |
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Post by cardsnweather on Jan 22, 2023 21:14:20 GMT -6
RGEM ticks N as well. And is way more bullish QPF wise. Good start to 00z At the surface, the nam is much further north. Haven’t dug into upper levels, but there appears to be big disparities in outcomes. Just comparing it to previous RGEM runs. Not the nam. |
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Post by landscaper on Jan 22, 2023 21:14:43 GMT -6
RGEM is a touch better than 18z not a lot , it shows 4-6” vs 3-5” at 18z. Not sure how the upper levels line up with the GY technique
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Post by cardsnweather on Jan 22, 2023 21:17:43 GMT -6
FV3 has a 994 in the bootheel and pouring snow over STL.
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Post by bdgwx on Jan 22, 2023 21:20:40 GMT -6
I mean the NAM shows the 850mb low crossing the Mississippi River at Festus with the -7 C isotherm bisecting it. The -5 C isotherm is bisecting it while it is still in Oklahoma. The -1 C isotherm is bisecting the surface low. There is a lot of warm air advection going on in that zone south of I-44 where temperatures are already cold. Now, whether 850mb temperatures end up being that cold in reality remains to be seen.
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Post by Worldserieschampions (Chicago) on Jan 22, 2023 21:26:30 GMT -6
00z Icon is pretty similar to previous runs favoring STL south.
So, nam is an outlier so far.
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Post by shrapnel - Arnold, MO on Jan 22, 2023 21:28:33 GMT -6
Bout to dust off the frivometer...
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Post by guyatacomputer - NE St. Peters on Jan 22, 2023 21:31:42 GMT -6
All the glowing predictions the cynical part of me is now waiting for Lucy to pull the football.
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Post by beaker - Dardenne Prairie, MO on Jan 22, 2023 21:50:31 GMT -6
Definitely think numbers on this thing is too early. I think most of the metro area is in for something of a moderate impact, mainly due to timing and the fact that it doesn't take much snow to snarl a rush hour. Still believe the area of great impact is somewhere south of 44, but that doesn't leave the northerners out. I think there should be accumulating snow for pretty much the entire area.
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Post by shrapnel - Arnold, MO on Jan 22, 2023 21:50:33 GMT -6
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Post by Snowstorm920 on Jan 22, 2023 21:53:44 GMT -6
GFS still looks the same as the last couple runs
Major snowstorm along and south of 44
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Post by Snowman99 on Jan 22, 2023 21:54:36 GMT -6
beaker you post like that 4 times a day, lol
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Post by Snowstorm920 on Jan 22, 2023 21:57:06 GMT -6
GFS QPF as snow  |
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Post by landscaper on Jan 22, 2023 21:58:36 GMT -6
Yes about the same nice look though
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Post by Worldserieschampions (Chicago) on Jan 22, 2023 22:03:06 GMT -6
Some 2” per hour rates seem possible/probable in the heart of the deformation band.
That will be quite the sight.
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Post by bdgwx on Jan 22, 2023 22:04:19 GMT -6
01Z NBM has the axis of heaviest snow paralleling, but south of I-44.  |
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Post by landscaper on Jan 22, 2023 22:06:59 GMT -6
Gem hold its course, way weaker and less qpf than NAM and GFS , I thought it might shift north some , but not at all
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Post by Snowman99 on Jan 22, 2023 22:14:57 GMT -6
it came north a bit, just not much
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Post by cozpregon on Jan 22, 2023 22:17:18 GMT -6
Gem's QPF is not close to what the 500 700 would suggest
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Post by Worldserieschampions (Chicago) on Jan 22, 2023 22:27:15 GMT -6
00z gfs ensembles look good.
Basically, need a European model to buy in with America if you live north of 70.
I understand the argument for adjusting to the upper level features. At the same time, probably important to question why the models are putting the bands where they are verbatim.
If the GYB is probability oriented, the dynamic models should be weighted in as is to some extent.
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