January Winter Threat Jan 6th - 8th

Thread starter #1

DDD

GON Winter Weatherman
Alright, so there is a lot and when I say a lot, I mean a lot to talk about.

Let's talk about social media and the internet as a whole for a second. If the threat for the South East continues or develops in the coming days, social media will blow up. My twitter feed is already starting to buzz. I urge caution though buying into pictures or statements from questionable sources. People have access to all sorts of information now and will post things willy nilly. Just because a map shows 4" of snow or .75" of ice in your back yard, does not mean it's gospel. We call those maps "clown maps" for a reason. They have all sorts of colors but they are not always accurate. They are simply there to give forecasters an idea of what's happening.

Also, for the love of PETE! Please don't get on the general discussion board and say, "My weather app or The Weather Channel app says 65° and sunshine" or "The 10 day forecasts shows 50° and rain". People, there is VERY LITTLE reliability in up to date and accurate forecast with weather apps. If that is your "source" for accurate weather data, I am sorry, you haven't been paying attention.

Let's get into the details. First and foremost, many METS who are much more knowledgeable than I, are talking about the "blocking" in the North East and the Upper Level Low (the storm) are causing problems run to run for models with a solution in the SE part of the United States. Basically, yes the solution could be accurate or it could be absolutely false because the model is spitting out a solution that is not really there.

On a personal note, I am HIGHLY skeptical of the current solution put out by the GFS. Why? Because it is a MAJOR Snow and Ice storm being modeled in a La Nina winter. It could still happen and the scenario that it cranks out is one for the record books. I just don't want people getting their hopes up just to have them wiped out. You will see what I mean below.

Also, the GFS has been showing a separate storm brewing around the Monday night / Tuesday / Wednesday time frame 8-10 days out. It has modeled that threat for the last 3 runs before the 18Z came out and moved the threat up 3 days.

So, for now, understand that we have a threat in the near future. The details are a little foggy at this point.

Please join me over at the General Weather Discussion page for questions and thoughts.

Pictures with descriptions will be posted below in separate threads.
 
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Thread starter #2

DDD

GON Winter Weatherman
These pictures are to show the ice threat. This would be Saturday night going into Sunday morning. Notice the 18Z (latest model) compared to what it said would be present 6 hours before. This is why I urge caution before buying into these solutions hook, line and sinker.
 

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Thread starter #3

DDD

GON Winter Weatherman
The cold layer will be deep enough according to the latest run of the GFS to bring what would be a significant snow storm to North Georgia.
 

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Thread starter #5

DDD

GON Winter Weatherman
So the GFS Ensemble is a hot bed of activity. This is the 18Z run. It probably won't verify in the end, but as a weather geek I am geeking out.
 

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Thread starter #6

DDD

GON Winter Weatherman
The GFS has held serve for quite a while now and cannot be ignored. Confidence is growing for a winter weather event that would start sometime Saturday evening / night and would go for about 18 hours. So we are looking at a Saturday night into Sunday afternoon event as far as precip goes. Temps are a whole nother story, it will get cold and not come back up above freezing for DAYS! (Thursday to be exact)

First and foremost, DO NOT get lost in those CLOWN maps that paint 14" of snow in Atlanta. The chances of that happening is like the chance of Tampa Bay winning the Super Bowl. What it does point to is winter weather inbound. It's not time to hit the panic button just yet. The EURO modeling has a light snow event not the major event that the GFS has.

Second, precip type will be most important to this system. I personally am more concerned about the freezing rain and ice potential at this point. The other thing that is concerning is the temps after the moisture is gone. The 2mm temps drop below freezing Saturday night and do not come up above freezing in Metro Atlanta area until Thursday. You read right. Thursday. 5 days below freezing according to the GFS.

None of this is forecast. I am simply telling you what the model says.

Another 24-48 hours obviously will build confidence. I am still looking at this event with caution. It's a La Nina winter, big snow events in GA and the SE are rare. I really get skeptical when I see freezing temps to Orlando and frozen precip models pointing to places as far south as Tifton.

I am going to post the precip type maps and not the accumulation maps. Those are garbage due to the amount of freezing rain and Ice pellets that will be falling as modeled. The maps below are in 6 hour intervals. You will have to use your imagination in between.

Last thing, we DO NOT want the freezing rain that is modeled. It would be devastating, but that too may be over done. Need more time, need more model runs and quite frankly we are talking about a storm that is not even on shore.

Just kidding, VERY LAST THING, for the love of Pete, figure out where your county is. When myself or Miguel post a map with thoughts or amounts, it never fails, I will have 4" painted over Gainesville and someone will say, how much for Oakwood? Please, know where you live. You may laugh, but you would be surprised.
 

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Thread starter #7

DDD

GON Winter Weatherman
A EURO model update:

Due to license agreements, I cannot post EURO model pictures unless they get posted by the host on social media. That said, the EURO just kills all the moisture out of the gulf and gives a very light snow event. Still puts down 1-2" of snow in Metro Atlanta with more than likely a light icing event on the front side of the system due to temps at the surface being below freezing.
 
Thread starter #8

DDD

GON Winter Weatherman
Alright so here is an update for the latest 18Z GFS modeling. The 18Z GFS is more of a snow event for roughly the I-20 corridor northward. A major ice storm is modeled for areas in the South East part of the state south of I-20. (120 Hour Map) What's even more interesting to me is how places like Augusta and Savannah get in on the action.

Right off the bat, let me say this looks to come in sometime around 3AM Saturday morning. Earlier I had said Saturday afternoon but that was an error on my part after looking at multiple model runs.

If you don't hear anything else I say in this post, hear this! Having followed weather and bird dogged winter storms since I was in my early 20's, one thing I know. The EURO is King and it is King for a reason. There are little signals in the energy and amount of precip that makes me think the GFS is headed towards the EURO solution which would be very little moisture and a light winter weather event.

The 00Z GFS is running so I will hold off posting pics and see what it does.
 
Thread starter #9

DDD

GON Winter Weatherman
Alright, the 00Z GFS and the 00Z Canadian models have just run and they are slightly less on moisture but still bringing what would be a significant winter weather event to the South East and when I say South East I mean South East.

The precip type is important and how much moisture is tapped is going to be the fly in the ointment. At this point you just want to keep an eye on the temps and the moisture and not get lost in amounts. As I stated before, looking at accumulation maps is going to make you look silly at this point. The models don't account for freezing rain or ice pellets. They see it all as snow and it's simply not accurate.

I am going to post the GFS precip maps and the Canadian accumulation map. I don't have any precip type maps for the Canadian so don't get lost in the amounts just understand this is where the Canadian model thinks the winter precip will accumulate.

Last, my personal opinion on this right now before I see the 00Z EURO model is that a mix of the GFS and EURO is safe at this point. That would mean a spread of snow from Macon to all points northward ranging from 1-4" based on location. Some areas will see more than others. I continue to be concerned about the ice potential depending on the depth of the cold at the onset of the moisture. It is way to early to start guessing at depths or numbers. I urge caution to anyone thinking this is going to be a monster storm. Could it become one? Absolutely! However that concern is not warranted at this time.

Last, let me be clear about something else, there is a post going around on Facebook from a guy in Dublin, Georgia saying that the EURO has been showing a blizzard and the GFS has come around to the EURO and a blizzard like 1993 is on the horizon. It has been shared more than 7,500 times. This is so irresponsible and completely WRONG. The EURO has never shown that and quite frankly has been the model with the least amount of moisture. Don't share or believe that post. It's awful on some guy's part to post stuff like that and get people all worked up in a frenzy.
 

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Thread starter #10

DDD

GON Winter Weatherman
12Z GFS and Canadian Modeling

Real quick update on the 12Z GFS and CMC models.

The GFS shifted slightly south of the 6Z model and still gives a nice hit of snow. A lot of that is probably ice pellets so the amounts it is showing I would divide in half.

The CMC model has a much deeper layer of cold and as modeled would be much more a snow maker than ice pellet maker.

All of this is still fantasy land as far as models go. The EURO from last night had a decent hit for Georgia but really plastered South Carolina and North Carolina.

I will not be around for the 12Z EURO modeling, but I will update on it when I get back in front of my computer.

Going to spend some time with my son.

Confidence is strong we will see something frozen, however amounts and where is as certain as a lottery ticket.

Lastly it cannot be stated enough, do not re-post absolute non-sense from people who scream "Blizzard" and "Storm similar to 1993". There is a nut down in Dublin, GA that wants to be weather famous. Unfortunately he has no clue what he's talking about.
 

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Thread starter #11

DDD

GON Winter Weatherman
Lets' jump right into some weather talk. There is a lot of information all over Twitter and Facebook and I am going to attempt to break it down for you the best way I know how. I will do my best to keep it simple and sweet.

Synopsis:

GFS: Snow in places. Some have 0 and some have 7"
CMC (Canadian): Broad Stroke of Snow
NAM: Starting to look a lot like the CMC
EURO: A whole lot of nothing

There is still a lot of unknowns. First unknown is how much sleet and freezing rain is mixed in and where the line changes from sleet and freezing rain to all snow. Right now in my mind the freezing rain / sleet line is somewhere south of Lagrange over to Just North of Macon (Monticello) over to Waynesboro. South of that line in my mind will be ice / freezing rain, but that band will only be about 25-50 miles wide before it changes to all rain going south. North of the line I believe it will be all snow and depending on how the moisture comes across, someone in GA is going to have a lot of snow 5-7" wherever the heaviest moisture comes across.

That's my guess as of now and that's all it is. A guess.

I can't express enough that it bothers me to no end that the EURO is not on board. I wish it was on board on some level. It would give me confidence in what will shake out.

I am going to post the precip type maps. You will notice that the snow is very far south, south of Macon, just north of Tifton. I expect the system to come North as modeled as we get closer to the event. They always seem to. It's why I think the CMC looks more realistic to me. We will have to wait and see.

As always, do not get lost in the depth of snow maps. Pay attention to the moisture, the type modeled and the freezing line. I put the clown map up for reference purposes only. I like the precip type maps so much more at this range than the amount maps. I also posted the Canadian clown map just for reference of the path the CMC is giving out.
 

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Thread starter #12

DDD

GON Winter Weatherman
From the NWS in Peachtree City:

.LONG TERM /Friday through Wednesday/...
Tricky forecast with upcoming winter weather event progged to
begin Friday into Saturday. The GFS continues to have the most
run-to-run consistency, with the swath and amounts of highest
accumulations varying little over the last 7-8 runs. ECMWF and CMC
models have trended towards the GFS solution over the last 24
hours, and the first peeks of the period in the Hi-Res models
are not too far off. Thus, the forecast pops, qpf and snowfall
accumulations are heavily weighted towards the GFS and GEFS (GFS
ensemble) solutions.

Confidence for this event is increasing, with low to medium
confidence on location and accumulations, and medium confidence on
timing. Several of the 12z model runs are beginning to indicate
the potential for light winter precip to begin Friday morning
(potentially before sunrise) across generally north Georgia. Amounts
should be light. Rain chances will increase from the south
through the day Friday as surface low feature lifts out of the
northern Gulf of Mexico. Cold temperatures will continue to drop
across north Georgia, combining with this moisture to promote a
transition from rain to snow, generally Friday evening. A switch
over to all snow is expected overnight and early Saturday for
areas generally north of a line from Columbus to Macon to
Swainsboro. Currently, the greatest potential for accumulating
snow is along and north of this line, with the swath of highest
accumulations extending from the AL/GA line (along the I-20
corridor) through the metro Atlanta area and into northeast GA
(including the NE GA mountains). In this area, 2-3 inches of snow
are possible with isolated higher amounts. Expect this snow,
particularly across north GA to be dry in nature, and have opted
to go with a 8 to 1 ratio of water equivalent to snow. Future
forecast packages may opt for an even higher ratio, producing
additional snow accumulation. A few things to note: due to the
position of the moisture, far NW GA is only expected to see around
1 inch of accumulation or less, and in portions of central
Georgia where snow is forecast, extended periods of rain or
rain/snow mix would result in lower snowfall accumulations.

Vertical profiles are suggesting a thick saturated layer overnight
Friday into Saturday morning, all below 0C. The combination of
this deep moisture layer and the nearly dry adiabatic lapse rates
suggest that the environment may support bands of heavy
precipitation, at times convective in nature. As of now, have
kept precipitation wording to either rain or snow, but will need
to monitor how future models are handling the evolution of the
event.

High pressure moves into the area Saturday afternoon, although
wrap around moisture could still produce light snow in portions of
NE GA. The high pressure should keep skies clear and temperatures
frigid through the remainder of the weekend. Expect snow
accumulations to stick around through Monday with lows in the
teens and 20s and highs remaining in the 30s. Dew point
depressions should allow some sublimation of snow to occur.
 
Thread starter #13

DDD

GON Winter Weatherman
Alright, lots of chatter now that we are close to the 48 hour window when the precip should be entering our area. The NWS in Peachtree City has come out and is very aggressive in their wording. For snow lovers in the N. GA area this bodes well. Minus the NW corner of the state.

Let me address the NW corner of the state first. Given how the wave comes out of the west and is riding along the Florida coast, turns the corner and goes up along the North Carolina coast, it simply leaves the NW corner of Georgia dry. Now this is only Wednesday and the wave could easily move 50 miles NW and you are in business. I am not saying you are out of the game at this point, what I am saying is CURRENTLY MODELED, the NW corner of the state of GA is dry.

Now the magic question that most of my followers on GON, or Twitter or my friends on FB want to know is... "HOW MUCH IN MY BACK YARD?" This is the magic question. I am not going to make a call map yet. However, I am going to give you an idea of how I see this setting up in my mind. There will be a lot of pictures in this blog as well and I will try and keep that clear.

There are multiple parts of this storm so I will try and hit the high points.

Timing. When will this come in? The 12Z GFS has the front of the snow line entering the Atlanta metro area sometime around 6-7PM Friday evening. The snow flies and becomes heavier over and through the next 12 hours and tapers off around 1PM Saturday afternoon. (All of this according to the GFS)

How much and where? Not going to get into how much at this point. Still too soon, however the WHERE is worth discussing. The GFS has the snow line down around Macon and tapering South West. The system is very positively tilted causing this NE to SW line look. I believe that line maybe a little far south. My thinking is a line from Columbus to Macon to Augusta and northward will be snow. This could be a scenario where the south side of Atlanta and points southward end up with more snow than folks on the north side. These are just my initial thoughts and not a forecast, let me be clear about that.

The Canadian and EURO modeling look similar to the GFS however in the Atlanta and most of Georgia area, those models are less in the moisture department. My North Carolina friends, you win on some level depending on the model.

My South Carolina folks, I believe a line from August to Columbia going NE, everything north of that will be snow. Yes, there will be a line where it goes from 3" here to 10 miles down the road a dusting. That will be great for some and totally suck for others. Same will be in Georgia. There will be "lines" where people jackpot snow totals and others are really ticked that they only see some flakes.

Last thing, the temps after the snow event is going to be bad. 2mm temp maps keep most of NGA in the freezer until Tuesday. Yep. Tuesday. Those maps are attached.

I am going to post up the precip type maps off the GFS, I am also going to post the Ensemble members of the GFS, the freezing rain map of the 12Z GFS, the Canadian snow total map and the 18Z NAM snowfall map which has taken a step towards the GFS.

I will take any and all criticism. This is not a forecast and I am not a pro, just a weather geek who has followed GA snow storms for 20 years. It's a sickness an addiction of sorts.

All predictions I will leave to the pro's. Mine is simply an opinion based on data, other really smart METS and weather geeks like myself.
 

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Thread starter #16

DDD

GON Winter Weatherman
Figured I would update with us being 48 hours out and the 00Z Guidance hitting the interwebs.

It seems like the models are starting to come into some agreement on what is going to take place and that is a good thing.

I am not going to wait up on the EURO tonight. The EURO is typically a good long range model and not worth my sleep. Maybe.

The GFS has gone about 10 runs now and has varied a little but not much. I kept thinking that thump of jackpot snow would disapear today but it won't let go of the idea. This storm seems to have a jackpot zone for the state of Georgia somewhere so wherever that ends up being, that will be quite a show.

Some probably wonder why the moisture does not paint evenly East as it goes towards South Carolina? The GFS is showing a warm nose riding right out ahead of the bulk moisture and it shows it initially on the East side of the state and eventually the cold air penetrates and turns everything to all snow, but that moisture on the East side initially will be rain. Obviously this "line" or warm nose is not set in stone. So time will tell.

Canadian model is much in line with the GFS and EURO modeling and quite frankly is a decent blend and reasonable solution in my mind.

Also of note, the UKMET has a much more colder and juicier solution which would mean more snow for everyone.

Notice how I avoided the NAM modeling? The NAM is the driest of all models and is suspect to me a this time. It's on an island with how dry it is even up stream into North Carolina where, no matter the modeling they seem to win the lion's share of snow.

Tonight I am going to show a few models and a cool statistic I found on another weather website I thought I would share.

First is the 00Z GFS precip models, the snow accumulation map, the Canadian accumulation map and the statistics for 3" or more of snow measured at the Airport in Atlanta.

Obviously things can change but the confidence in how this will shape up is growing.

Last but certainly not least, everything you read here is my opinion, my words. I don't copy and paste other's words here. I don't have to. If I don't have time to post an update, I don't post an update. Also, I don't keep my opinions "secret" because I want as many people to be informed, enjoy the fascination of snow in the SE as possible!!! It's why I blog in a couple of different PUBLIC places. Others cannot honestly say the same, yet they run around Facebook in what they think is "secret places" seeking as much attention as possible when snow, ice or extreme weather is on the horizon. I think that's pretty sad. Always give credit for someone else's work or knowledge, maybe just maybe you learned your lesson. Looks like you did. We will see and when I say we, I mean we.

Also, sorry Dublin, GA no snow for you despite what your "resident weather nerd" said earlier this week when he set the internet on fire calling for a blizzard and caused the biggest headache known to man for the Macon weather outlets and he's still posting nonsense! Good Grief.

Alright, I am off my soap box. For now.
 

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Thread starter #18

DDD

GON Winter Weatherman
Alright, so I am going to go out on a limb and give everyone a call map.

It is hard to get away from the GFS. It has held onto the solution so consistently. Quite frankly the EURO and the CMC have come to the GFS's way of thinking. The UKMET model has been even more amped up than the GFS.

There is concern about temps. Temps may causing mixing issues at the onset but in short order, rain will turn over to all snow for most points I would say just north of Macon. The storm is not going to be horizontal in nature, it's going to be at somewhat of a 45-60° angle. That's because of the cold and how the moisture is interacting with the cold air.

Latest 12Z GFS has come a touch north and is more rain south and not as much snow down towards Macon.

Let's break it down:

A: I am really sorry for you folks in NW GA. This area is going to be moisture starved. A trace to 1/2" is what I expect in this region.

B: This is going to be a mixed bag due to elevation, snow rates and mainly moisture. The mountain areas may get some dynamic lift and get way more than any model can project. Upper air dynamics will favor lift and mountain areas could get under heavy bands of moisture.

C: This area is for my friends in the upstate of S.C. I think this area is favored well for a good 3-6" solid SE snow storm. The GFS, EURO, CMC... all have had a good hit for this area. If you live in this region, I would shine the sleds have them ready to go.

D: This area is going to be 1-3" and it's going to be more going towards "E". The drop off of moisture to increase of moisture line is going to be very sharp somewhere in this area. That line won't be determined until it's happening.

E: This area is going to be the sweet spot. Yes, it includes my back yard. The GFS will not back off the idea of jackpotting an area in this zone. It's had it for 3 days now. I have to believe it's onto something. It's going to be that area where it gets over to snow the fastest and gets the most moisture. I have to think that is what the modeling is keying on. Again, the edges of this area will vary in having 4" and 10 miles down the road they only have 2". I think this area will be 3"-5" with some areas going as high as 7-8" in jackpot areas.

F: This is the trickiest area to call. Somewhere in this zone it will transition from snow to rain. It will break someone's heart and make someone's winter in this area. I think anyone in this area has real chance at 1-4". Obviously the closer you are to the "E" zone the higher the totals.

These zones are not written in stone. People will say "I am right on the line" or "I am out of it". We are still 36-48 hours out of the actual event.

THIS MAP WILL CHANGE and IT'S JUST SOME AMATEUR WEENIE'S GUESS.

Last, the temps behind this system cannot be ignored. I have included those maps.

WE DO NOT COME OUT OF THE FREEZER UNTIL TUESDAY!
 

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Thread starter #20

DDD

GON Winter Weatherman
Alright, just a late night update.

I am not going to change my map. I still like it. If I was going to change anything I would account for the warm nose that the NAM and GFS are showing on the East side of the state. If that warm nose does happen as modeled it could really eat up some snow. Heck, Where it jackpots Gwinnett County, the warm nose edges up through Oconee County and robs Clarke County. It will not take much to not have that much or for it not to be as strong and up goes the snow totals.

Other than that, I like my call for now.

I will be watching short range models at this point and where the wave coming out of the West is at vs. model guidance.

I have no idea why schools are closing early tomorrow. This is not going to hit the metro area until the 8-9PM time frame. Maybe they want to get ahead of traffic? I have no idea.

I will update the blog if any major changes happen.

One thing that people always seem to do is freak out as the storm gets right at our door step. They start to think things won't turn out as planned. While that is possible, resist the urge to jump off a cliff or tall building.
 

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