SnowGoose69

I can’t tell really on the 12Z RGEM but it appears to be not as amped as the 18z NAM in your area either. The ukmet is darn close though. 850 is like -0.4C in ATL the entire event

It sucks not having the RGEM because it can really let you know if the NAM is out to lunch or not

Be real careful with the warm ground deal. I find that doesn’t work often. If you’ve got a December sun angle and you snow even one half inch per hour the warm ground deal doesn’t often hold up. Many places jn GA have been in the 40s now for 36 hours plus. I always bring up Albany NY being 85 degrees and then seeing 15 inches of snow the next day

The GFS didn’t see the warm nose in that storm. Unfortunately the nws and many forecasters bought into it partially and kept snow totals too high when it was evident the event was likely going to be mostly FZRA

I would be shocked if ATL got anything big from this. It’s possible but making a forecast here you really have to go just up to 2 inches on cold surfaces. This isn’t a closed low or dynamic system where intense rates are likely and it’s occurring at a bad time of day for accumulation. One factor I think that is killing this for ATL is what I call “early wet bulbing” where you get precip too early before dry air really works in and when you finally do start going to all snow you don’t have the potential you would have had if you stayed dry. If for whatever reason the precip from 23-07Z stays south of ATL and they can get to 23-24-25 on dewpointa this even becomes much more dangerous for them

That event had a lousier cold air supply and was more dynamic forcing mild air into the 750-900 layer

The Euro wasn’t similar to the GFS in AL/GA/MS really. More for areas north. The Euro had 4-5 inches of snow in ATL while the GFS had none

It was much wetter overall than the NAM

And the 18Z NavGEM looks more west than the 12. At least we know some models, even if it’s the bad ones aren’t giving in

Through late Friday afternoon it appeared like it was going to possibly came way west but then thereafter that it appeared to be flatter and more east. It was definitely more west for AL/GA on the precip but areas further up the MA region it was more east and drier

The new SREF definitely sort of hints what the Euro showed. Things looked better thru 54-57 then it wasn’t as good as the previous run after that especially more north

The Op Euro since the upgrade 2 winters ago in systems that aren’t overly strong at the surface has tended to have a flat bias. I think the ensembles are definitely going to be more north and west. The Euro also tends to make slow adjustments. Sometimes if models are catching onto the setup late the Euro can still be making adjustments inside 12-18 hours

Many cases where the low is above 995-998mb it’s happened

The last few years when the NavGem has been this far north and west at this range it’s rarely not led to the flatter models coming further west

It’s hard to know without details but the UKMET I’m guessing wouldn’t even be snow in ATL. That’s probably the more classic BHM-RMG-CHA snow track

These types of systems are probably the most favorable for that region because they do not tend to move NW as much with time because they don’t have the deep surface low. I’ve seen plenty end of destroying MCN though and missing ATL

The RGEM is in though 42 and is insanely far NW at 42 compared to the 06Z run at 48

Climatologically wise that is not the worst idea. I always tell people, do not forecast near record or record amounts unless model agreement is high.

Xiamen gusting to 80mph and their wind is offshore which means the center passed northeast of them. You'd have to think places just east of center gusting to 100-110. Satellite appearance I think this is a 95-100mph storm, not 125 as JTWC has

The RGEM had been dreadfully slow since its upgrade last year with most events. Using the NAM though which also tends slow I would say anyone from about central northern NJ east sees nothing before 10pm other than spotty light rain here or there.

Its gonna be tight for NYC, my hunch now is it will make it and stall just west of them the stuff off NJ is slowing its west progress which likely means we'll see the west progress slow up north within 1-2 hours.

Down in NYC the Euro may still end up more correct than the GFS or RGEM, the RGEM is verifying too far east right now down there, we have mod-heavy snow in portions of west-central LI it is not seeing or has 50 miles further east. The 12Z Euro will probably end up being off 30 miles on its west edge but because its impacting 20 million people, everybody is going to notice it, if it was over AVP or ABE hardly anybody would.

I was joking when I said Newark may see 8 inches and JFK 20 but it may be close to that.

They'll verifiy 2 feet on central and ERN LI, its NYC they may get killed, but even there I think ends up around 12-14, the RGEM has about that for NYC.

The RAP's forecast at the end of it's run would suggest the GFS and RGEM are closer to reality than the NAM or Euro, the RAP has a known west bias beyond 12 hours and it's barely getting heavy snow to NYC, the Euro may be going down on this event