SnowGoose69

It’s still too early to know if this south push is a long term move. We’ve seen this occur before around this 3-4 day range and then as soon as everything comes ashore and is sampled the models pull a 180 one way or another and never move back

If I remember right the UKMET runs warm on wedge events at this range so odds are you can pull that ice further southwest if that solution verified

I think there will be major ice down to areas NE of ATL. I’m not sure if it makes it into the Metro at all. Especially given it would have to occur mid way through the event. Most icing events in ATL are from the start of the precip or not at all

The bigger concern would probably be that ATL might be in bigger trouble than anyone initially thought. The fact the Euro wants to push snow that far into Georgia gives me doubts that freezing temps don’t reach down there. Right now not one forecasting outlet is giving more than a remote chance it does

The high is too far north for those sorts of totals into GA and SC. That would at best be mostly sleet there. Think January 88. It was a flatter setup than this was or at least a weaker low, later in the season and still most of NRN AL and GA saw sleet. This probably is north of the 12Z Euro in the end but even if that verifies dead on those places south of the TN-Spartanburg line are likely sleet. Atlanta might even be rain

The wedge appears to me to build in way too late for them. I could be wrong but simply looking at timing it seems they’d precipitate for too long prior to the wedging so it would be 35-38 and rain. It’s still very far out though.

If you didn’t know any better looking at satellite today you’d think Florence had its own mind and deliberately deviated north to get away from the shear and dry air and now said okay I’m resuming course again.

Correlation coefficient still showing the R/S line more or less straddling interstate...85 I believe from ATL airport down about 20 miles or so but it is pushing ESE

The Obs over AL in that snow band are not impressive, but the 700-850mb temps in that area such as MGM are not anywhere near as ideal as they will be over the ATL metro. Many places are -1 to -2C at 700 while ATL will be near -7-9C at 09z

RGEM looks like it changes BHM over at 11Z or so

Dewpoints just seem too high right now. If those do no start dropping I don't see how any significant snow occurs there

I would not even bother with the GFS at this point for thermals. Use it for precip axis only and maybe storm track

The RGEM even shows the R/S line going north after 20Z in GA due to precip shutting off or slowing down.

RGEM snow maps make no sense. Seems to show significant snow at ATL but the ptype algorithm on TT shows mostly rain other than a brief 3 hour period

RGEM on ptype maps appears to be mostly rain at ATL other than from 15-18Z or so.

Don't use the HRRR that far out.

The 00Z NAM to me looks like it slide south across GA/AL. Thats purely looking at precip field...not thermals

I know last year that ATL got their first ever severe freezing rain event without a wedge so anything can happen

I'm sure people here know better than me but I want to say GA commonly snows with thicknesses over 540

Almost has ATL in rain now. Its definitely been coming north with time

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