Jan 25/26 Storm Threat...(Part 3)

[eyewall]

Screw the models they are a joke whether it is 1 day away or a week away. How about we all just move to Antartica and be happy with tw guaranteed cold and snow there without having to worry about the week plus fantasy land, one day reality models.

THE MODELS ARE A POS POINTLESS WASTE OF TAX PAYERS MONEY AND SHOULD BE SCRAPPED FOR MONEY TOWARDS WORLD DEBT

Take it to the banter thread tough guy.

[Lookout]

Kudos to Foothills who has been consistent with this idea. Foothills, you won't have to tear your degree up. And for those that yelled about nothing but rain for these areas....

Nothing like distorting what people have said and claiming verification before the storm even happens. It's been repeated a number of times by myself and others on the rain train that higher elevations of nc/extreme nc ga and eastern tn are likely to pick up some.So no one really disagrees with that and saying so is a total distortion of what people have been saying. But with the exception of the higher elevations of northern alabama, it looks pretty warm at the surface for the most part and by the time the mid levels cool, precip is on it's way out.

I sound like a broken record here but 12z euro is rain for everyone outside the higher elevations in ga and the carolinas. 850s of plus 4 to 8c over a lot of the carolinas until the end. Even the mountains of nc don't fair too well as the euro has the 0c 850mb isotherm hugging the nc/tn border, suggesting a good bit of rain in lower to mid elevations. Canadian is as well..in fact it's a lot warmer there. 850s are barely below zero in northern alabama on the euro with surface temps in the upper 30s to near 40 for a good chunk of the event.

[Shawn]

Screw the models they are a joke whether it is 1 day away or a week away. How about we all just move to Antartica and be happy with tw guaranteed cold and snow there without having to worry about the week plus fantasy land, one day reality models.

THE MODELS ARE A POS POINTLESS WASTE OF TAX PAYERS MONEY AND SHOULD BE SCRAPPED FOR MONEY TOWARDS WORLD DEBT

Uhm. They're a tool that forecasters use.

[HKY_WX]

Screw the models they are a joke whether it is 1 day away or a week away. How about we all just move to Antartica and be happy with tw guaranteed cold and snow there without having to worry about the week plus fantasy land, one day reality models.

THE MODELS ARE A POS POINTLESS WASTE OF TAX PAYERS MONEY AND SHOULD BE SCRAPPED FOR MONEY TOWARDS WORLD DEBT

world debt.

[Shawn]

For anyone wondering about the CAE area, it should all be rain. I'm not even seeing much of a chance at a start or end as something wintry at this point. All models are much too warm for this next system. I pretty much felt this would be the outcome since 3-4 days ago.

[crossthread]

Check-out KLIM's take on this.

They say we'll be 50'ish at the on-set, but OTOH, say were -7 off normal climo......(and currently 45, Busting on the Low side today)...

So that will put us in the , (If this "Storm", trends colder & south or East of OP, say just to the South of ILM, things could get interesting even Here.

As the AFD gives a short and sweet, (Shortest I've read in a LONG time), Forcast..

I've heard more times than this about a March 93 scenario playing out or the March 03/05?(03 had 3', & 93 storm had 1.7") WE DID see snow as the Dynamics played out over us.... (What a crazy storm! ie: 93)... Of snow in ILM...

As this AFD shows, it may give a "hint" for you folks up that way...

Synopsis...

Arctic high pressure will prevail today and tonight. Warmer

temperatures will develop Monday and Tuesday. A strong storm

system will move across the area late Tuesday and Wednesday with

wind and rain. High pressure will build back in for the end of the

week.

&&

Near term /through tonight/...

as of 9:00 am Sunday...recent jumps in temperature show that the

surface based inversion has broken. A slower diurnal curve is

expected over the next several hours as solar insolation leads to

vertical convective mixing. Some middle and high clouds paralleling a

west-east cold front across the northern Gulf states will be

spilling into the region as the day wears on. Little to no changes

from the previous forecast expected at this time.

Given expected temperatures today/tngt...this will mark the 21st

day in a row that the "average daily temperature" has been held in

check below the normal. 21 of 23 days in January 2011 have below

normal. We are running about 7 degree f below normal in this category.

&&

Short term /Monday through Tuesday night/...

as of 3:00 am Sunday...focus for the short term now begins to shift

to the dynamic storm system moving across the area Tuesday into

early Wednesday. Major models have shifted to a slower solution and

are in general agreement with a potent middle level feature moving

across the Tennessee Valley with the surface low moving well inland

of the coast. With this scenario...all sorts of considerations. (never heard this before out of this office.)

First...have increased probability of precipitation to likely in most areas and increased

quantitative precipitation forecast amounts...this primarily for Tuesday evening into Wednesday

morning. Ptype should not be an issue even with Tuesday morning mins

dipping to below freezing in some areas inland as the slower

solution should allow ample time for the boundary layer to modify. HUH??? read on

The strength and placement of the system should overwhelm any wedge

scenario in our area. (Cold or WArm Wedge?)..... Prolific wind fields...as would be expected

with this type of solution...brings a severe weather possibility

into play. For now...it looks like a typical high shear/Low Cape

event for the area. Uncertainties remain with this threat however

and Storm Prediction Center has not included any highlighted areas in the latest day

three outlook.

Hmmmm....

[Lookout]

Screw the models they are a joke whether it is 1 day away or a week away. How about we all just move to Antartica and be happy with tw guaranteed cold and snow there without having to worry about the week plus fantasy land, one day reality models.

THE MODELS ARE A POS POINTLESS WASTE OF TAX PAYERS MONEY AND SHOULD BE SCRAPPED FOR MONEY TOWARDS WORLD DEBT

This rant from you has gotten old. See you in 3 days.

[Cheeznado]

Nothing like distorting what people have said and claiming verification before the storm even happens. It's been repeated a number of times by myself and others on the rain train that higher elevations of nc/extreme nc ga and eastern tn are likely to pick up some.So no one really disagrees with that and saying so is a total distortion of what people have been saying. But with the exception of the higher elevations of northern alabama, it looks pretty warm at the surface for the most part and by the time the mid levels cool, precip is on it's way out.

I sound like a broken record here but 12z euro is rain for everyone outside the higher elevations in ga and the carolinas. 850s of plus 4 to 8c over a lot of the carolinas until the end. Even the mountains of nc don't fair too well as the euro has the 0c 850mb isotherm hugging the nc/tn border, suggesting a good bit of rain in lower to mid elevations. Canadian is as well. 850s are barely below zero in northern alabama with surface temps in the upper 30s to near 40 for a good chunk of the event.

I disagree about Georgia on the Euro- if the upper low takes the track the Euro has, some lower elevations especially in NW GA maybe down to the northern ATL suburbs would get a few hours of snow and maybe a couple inches especially on the bushes/grassy surfaces. With strong dynamic cooling the actual 850 temps may end up colder than progged IF the upper/mid level low goes far enough south. Some areas farther south could see this scenario: Mostly rain, then at peak omega time a burst of heavy snow for an hour or two, then back to rain again. This could be very localized. Now if the upper low goes a bit farther north it is a moot point, GA except the peaks gets all rain. We will not totally get a handle on that for another day of two probably.

[CAD_Wedge_NC]

I didn't see any Euro QPF in the PBP.

[FoothillsNC]

I disagree about Georgia on the Euro- if the upper low takes the track the Euro has, some lower elevations especially in NW GA maybe down to the northern ATL suburbs would get a few hours of snow and maybe a couple inches especially on the bushes/grassy surfaces. With strong dynamic cooling the actual 850 temps may end up colder than progged IF the upper/mid level low goes far enough south. Some areas farther south could see this scenario: Mostly rain, then at peak omega time a burst of heavy snow for an hour or two, then back to rain again. This could be very localized. Now if the upper low goes a bit farther north it is a moot point, GA except the peaks gets all rain. We will not totally get a handle on that for another day of two probably.

excellent post and thats how I feel about this now. Its too bad we can't even get a real good handle yet on the surface track, but this is an evolving dynamic system, so thats how it goes usually with these things. One thing I'm finding odd is how "uncold" it is with the 5H core as it develops in N. Alabama area, then strengthens. That should be a little colder I'd think. I think its going to be a fun storm to follow, full of surprises, no doubt.

[Carvers Gap]

Nothing like distorting what people have said and claiming verification before the storm even happens. It's been repeated a number of times by myself and others on the rain train that higher elevations of nc/extreme nc ga and eastern tn are likely to pick up some.So no one really disagrees with that and saying so is a total distortion of what people have been saying. But with the exception of the higher elevations of northern alabama, it looks pretty warm at the surface for the most part and by the time the mid levels cool, precip is on it's way out.

I sound like a broken record here but 12z euro is rain for everyone outside the higher elevations in ga and the carolinas. 850s of plus 4 to 8c over a lot of the carolinas until the end. Even the mountains of nc don't fair too well as the euro has the 0c 850mb isotherm hugging the nc/tn border, suggesting a good bit of rain in lower to mid elevations. Canadian is as well..in fact it's a lot warmer there. 850s are barely below zero in northern alabama on the euro with surface temps in the upper 30s to near 40 for a good chunk of the event.

Lookout. I know you are a bit of an expert on thermal profiles. I am finally able to see the 12z Euro in six hour increments on the accout I have. The 850 mb 0c line(don't have access to surface temps) basically holds south of NE TN and SW VA throughout the event on Tues-Wednesday. The 0c line makes an attempt to push north of the area at 60 hrs. Pushes slightly north at 66 hrs into SW VA, but crashes back in as the low passes. To me that says that snow/rain mix is what happens initially. Could be more snow or rain in the first six hours of the event depending on time of day I think. Then around 66 it switches to rain (w/ flakes mixed in), and then back to snow at 72. Depending on the moisture available I would think some accumulating snow is possible in the western foothills of the southern Apps as the low slides by. Is that a correct assumption, or am I missing something as I assess this? Not trying to be a smart you know what about this. Just trying to learn.

[burgertime]

I didn't see any Euro QPF in the PBP.

For this storm it's as wet as the GFS and NAM I'm afraid, would probably be around .50 for WNC and .75 for the eastern sections.

[packbacker]

I didn't see any Euro QPF in the PBP.

0.75" in all NC/SC/GA and transitions to 1" around RDU or maybe just east and more down at the coat of NC/SC. Also, little blob of 1" QPF in N-GA.

[CAD_Wedge_NC]

For this storm it's as wet as the GFS and NAM I'm afraid, would probably be around .50 for WNC and .75 for the eastern sections.

Thanks Burger.

[Carvers Gap]

I didn't see any Euro QPF in the PBP.

Through 96 hrs, draw a line from northeast Louisiana to southwest PA, and it is .5 or higher to the southwest of that line for everybody.

[DixieBlizzard]

This is random and means nothing in the long run but FFC forecasted a high today for me of 45F. Made it to 40 so far. Not busting on FFC at all as it is all the fault of MAV/MOS guidance (sorry for a little sarcasm). That guidance, this morning, was wrong about TODAY probably on the order of at least 4 to 5 degrees. This storm is still about 3 days off now that the timing has changed again. I'll be the first to admit I don't plan on seeing anything for my backyard but this thing has Smokie Mountain special written all over it. Wish I could go!

[Lookout]

yeah its just for entertainment. The one thing I'm interested in to see if it verifies is the big PNA out west. We've yet to really get one of those, and the models have tried and tried, but it just hasn't happened, so we'll see. The same thing actually happened with the late November -NAO, but eventually it did indeed happen. So it if does happen, obviously this Winter will be a cold one. Its already Jan 23 and we can safely see the next 10 days to 2 weeks with no above average temps around the Southeast. And probably if you infer more you can go out to 3 weeks as being likely colder than average, which would take us into mid Feb. That only leaves 2 weeks of Meteorological Winter , so even if it did warm to above average, we've got probably a solid 10 out of 12 weeks at below normal temps I think. Thats pretty astounding when you think of it. We lose the neg NAO and gain the PNA, its completely perfect timing, if you're a cold lover. So in essence , for some areas of the Southeast we could already be a top 5 cold/snowy Winter, and if we get anything else to happen (generally speaking), this could translate to a top 2 (or even 1?) for some areas of the Southeast, if you combine the cold +snow in some sort of hierarchical ranking system...which I don't know if they do

Good post. This winter has been awesome and it just tickles me to death that all the forecasts that had us warm and dry are going to be 100% dead wrong. I don't think I have ever seen so many winter forecasts end up being so wrong and it makes me think many of them need to go back to the drawing board.

I mean think about it, so many had us so warm and dry and this already is a top 5 winter for many but might end up being one of the best winters in decades for the southeast. That is astoundingly delicious lol

The persistence of the cold has been truly amazing. The lack of any warm spells has been really noticable. Most winters we have at least a few spells of temps in the 60s here..not this year. Indeed the best we have managed is average or barely above average on a few days, otherwise it's all been below normal. Whether it's above normal or below normal, to have such persistence in either is rare but persistent cold is especially rare down here.

And like you said, no signs of it abating anytime soon. In fact the few days after this storm might be our warmest for a while. I'm betting people who hate cold and snow have been absolutely miserable this year. I hope their misery continues

It's a shame this storm is lacking cold air but it's not our last chance it would appear which should ease the pain of most. Hopefully what happens after day 7 will make everyone happy.

[Marion_NC_WX]

GSP Discussion...

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...

AS OF 230 PM SUNDAY...MODEL SOLUTIONS DIVERGE FOR THE SHORT TERM

PERIOD MAKING IT EXTREMELY DIFFICULT TO PIN DOWN ANY SPECIFICS

REGARDING THE EXTENT OF WINTER WX ACROSS THE AREA TUE-WED. THE TRACK

OF THE SFC LOW...TEMPERATURES AND THKNS PROFILES VARY WIDELY WITH

SOME MODELS INDICATING A SIGNIFICANT WINTER EVENT FOR THE MTNS WHILE

OTHERS SHOW WARMER TEMP PROFILES. IN ANY CASE...AT LEAST ADVSRY

LEVEL SNOWFALL IS PSBL FOR THE MTNS TUE NIGHT-WED. WITH THIS

UNCERTAINTY IN MIND I USED A MODEL BLEND TO TRY TO IRON OUT MOST OF

THE DIFFERENCES. ONE THING GUIDANCE HAS IN COMMON IS A 500MB TROF

DIGGING ACROSS THE S PLAINS MON NIGHT AND TOWARD THE LOWER MS VALLEY

TUE. MOST MODELS TRACK THE SFC LOW S OF THE CWA WHILE THE GEM KEEPS

IT N AS IT MOVES TO THE COAST WED. FAVORED A COMPROMISE HERE AS WELL.

AS THE SYSTEM MOVES ACROSS THE DEEP S TUE-WED...MOISTURE WILL SURGE

N ACROSS THE REGION. LOWS MON NIGHT WILL COOL INTO THE M20S-L30S

ACROSS THE PIEDMONT WITH 20S MTNS. HIGHS TUE WARM INTO THE M-U40S

ACROSS THE PIEDMONT WITH M30S-M40S MTNS. LOOK FOR INCRSNG POPS

DURING THE DAY TUE. EVEN CONSIDERING WARMER SFC TEMPS IN THE

MTNS...WET BULB TEMPS AND COOLER AIR ALOFT WILL STILL ALLOW FOR A

CHANCE OF WET SNOW IN THE AFTN...WITH A CHANCE OF RAIN E OF THE

MTNS. AS TEMPS COOL TUE NIGHT AND DEEP MOISTURE BLANKETS THE AREA...

CATEGORICAL SNOW WILL DEVELOP IN THE MTNS AND ADJACENT FOOTHILLS

WITH A RAIN-SNOW MIX DOWN TO ABOUT THE I-85 CORRIDOR...WITH RAIN

FARTHER S. TEMPS ARE ONLY EXPECTED TO WARM A COUPLE DEG WED WITH

RAIN LIKELY ACROSS THE PIEDMONT WED MRNG AND SNOW IN THE MTNS.

PRECIP SHOULD DIMINISH LATE WED AFTN AS DRIER AIR WORKS IN FROM THE

SW.

&&

[Weather Czar]

Checking temp profiles for my area. The Nam is very close. Just a small warm layer at 850 down to the surface at 925. The column is below freezing above 850. My 12z euro maps are not updated yet but this is about how they looked on the 0z run from last night temp wise. Robert, With high rates can i overcome this small warm nose from 850 down to the surface which is 925. Temps from are about 33-34 to around 36 at the surface. The weenie in me wants to think alot of with this setup. But im not very confident and my head tells me a mix.

[Weather Czar]

GSP Discussion...

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...

AS OF 230 PM SUNDAY...MODEL SOLUTIONS DIVERGE FOR THE SHORT TERM

PERIOD MAKING IT EXTREMELY DIFFICULT TO PIN DOWN ANY SPECIFICS

REGARDING THE EXTENT OF WINTER WX ACROSS THE AREA TUE-WED. THE TRACK

OF THE SFC LOW...TEMPERATURES AND THKNS PROFILES VARY WIDELY WITH

SOME MODELS INDICATING A SIGNIFICANT WINTER EVENT FOR THE MTNS WHILE

OTHERS SHOW WARMER TEMP PROFILES. IN ANY CASE...AT LEAST ADVSRY

LEVEL SNOWFALL IS PSBL FOR THE MTNS TUE NIGHT-WED. WITH THIS

UNCERTAINTY IN MIND I USED A MODEL BLEND TO TRY TO IRON OUT MOST OF

THE DIFFERENCES. ONE THING GUIDANCE HAS IN COMMON IS A 500MB TROF

DIGGING ACROSS THE S PLAINS MON NIGHT AND TOWARD THE LOWER MS VALLEY

TUE. MOST MODELS TRACK THE SFC LOW S OF THE CWA WHILE THE GEM KEEPS

IT N AS IT MOVES TO THE COAST WED. FAVORED A COMPROMISE HERE AS WELL.

AS THE SYSTEM MOVES ACROSS THE DEEP S TUE-WED...MOISTURE WILL SURGE

N ACROSS THE REGION. LOWS MON NIGHT WILL COOL INTO THE M20S-L30S

ACROSS THE PIEDMONT WITH 20S MTNS. HIGHS TUE WARM INTO THE M-U40S

ACROSS THE PIEDMONT WITH M30S-M40S MTNS. LOOK FOR INCRSNG POPS

DURING THE DAY TUE. EVEN CONSIDERING WARMER SFC TEMPS IN THE

MTNS...WET BULB TEMPS AND COOLER AIR ALOFT WILL STILL ALLOW FOR A

CHANCE OF WET SNOW IN THE AFTN...WITH A CHANCE OF RAIN E OF THE

MTNS. AS TEMPS COOL TUE NIGHT AND DEEP MOISTURE BLANKETS THE AREA...

CATEGORICAL SNOW WILL DEVELOP IN THE MTNS AND ADJACENT FOOTHILLS

WITH A RAIN-SNOW MIX DOWN TO ABOUT THE I-85 CORRIDOR...WITH RAIN

FARTHER S. TEMPS ARE ONLY EXPECTED TO WARM A COUPLE DEG WED WITH

RAIN LIKELY ACROSS THE PIEDMONT WED MRNG AND SNOW IN THE MTNS.

PRECIP SHOULD DIMINISH LATE WED AFTN AS DRIER AIR WORKS IN FROM THE

SW.

&&

The nam starts me as snow then i warm just above freezing at 850. The GFS is above freezing here up to 750mb.

[strongwxnc]

So many questions for our small area Dan.....

GSP Discussion...

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...

AS OF 230 PM SUNDAY...MODEL SOLUTIONS DIVERGE FOR THE SHORT TERM

PERIOD MAKING IT EXTREMELY DIFFICULT TO PIN DOWN ANY SPECIFICS

REGARDING THE EXTENT OF WINTER WX ACROSS THE AREA TUE-WED. THE TRACK

OF THE SFC LOW...TEMPERATURES AND THKNS PROFILES VARY WIDELY WITH

SOME MODELS INDICATING A SIGNIFICANT WINTER EVENT FOR THE MTNS WHILE

OTHERS SHOW WARMER TEMP PROFILES. IN ANY CASE...AT LEAST ADVSRY

LEVEL SNOWFALL IS PSBL FOR THE MTNS TUE NIGHT-WED. WITH THIS

UNCERTAINTY IN MIND I USED A MODEL BLEND TO TRY TO IRON OUT MOST OF

THE DIFFERENCES. ONE THING GUIDANCE HAS IN COMMON IS A 500MB TROF

DIGGING ACROSS THE S PLAINS MON NIGHT AND TOWARD THE LOWER MS VALLEY

TUE. MOST MODELS TRACK THE SFC LOW S OF THE CWA WHILE THE GEM KEEPS

IT N AS IT MOVES TO THE COAST WED. FAVORED A COMPROMISE HERE AS WELL.

AS THE SYSTEM MOVES ACROSS THE DEEP S TUE-WED...MOISTURE WILL SURGE

N ACROSS THE REGION. LOWS MON NIGHT WILL COOL INTO THE M20S-L30S

ACROSS THE PIEDMONT WITH 20S MTNS. HIGHS TUE WARM INTO THE M-U40S

ACROSS THE PIEDMONT WITH M30S-M40S MTNS. LOOK FOR INCRSNG POPS

DURING THE DAY TUE. EVEN CONSIDERING WARMER SFC TEMPS IN THE

MTNS...WET BULB TEMPS AND COOLER AIR ALOFT WILL STILL ALLOW FOR A

CHANCE OF WET SNOW IN THE AFTN...WITH A CHANCE OF RAIN E OF THE

MTNS. AS TEMPS COOL TUE NIGHT AND DEEP MOISTURE BLANKETS THE AREA...

CATEGORICAL SNOW WILL DEVELOP IN THE MTNS AND ADJACENT FOOTHILLS

WITH A RAIN-SNOW MIX DOWN TO ABOUT THE I-85 CORRIDOR...WITH RAIN

FARTHER S. TEMPS ARE ONLY EXPECTED TO WARM A COUPLE DEG WED WITH

RAIN LIKELY ACROSS THE PIEDMONT WED MRNG AND SNOW IN THE MTNS.

PRECIP SHOULD DIMINISH LATE WED AFTN AS DRIER AIR WORKS IN FROM THE

SW.

&&

[Weather Czar]

So many questions for our small area Dan.....

This is so close to a major storm it's not even funny. Or could just be a sloppy cold mix.

[Cheeznado]

The Euro ensembles are out- not good news for GA- good news for TN and the mountains. The ensemble mean deepens the storm faster in TX and it becomes negatively tilted faster in western TN which translates to a faster and farther north track for the mid-upper low and also the surface low. This would mean little chance for snow except in the higher peaks of GA- and also NC would mainly be a mountain event. I hope the Op is better than the ensembles in this case. but my hope for snow here just went down a notch.

[FoothillsNC]

Good post. This winter has been awesome and it just tickles me to death that all the forecasts that had us warm and dry are going to be 100% dead wrong. I don't think I have ever seen so many winter forecasts end up being so wrong and it makes me think many of them need to go back to the drawing board.

I mean think about it, so many had us so warm and dry and this already is a top 5 winter for many but might end up being one of the best winters in decades for the southeast. That is astoundingly delicious lol

The persistence of the cold has been truly amazing. The lack of any warm spells has been really noticable. Most winters we have at least a few spells of temps in the 60s here..not this year. Indeed the best we have managed is average or barely above average on a few days, otherwise it's all been below normal. Whether it's above normal or below normal, to have such persistence in either is rare but persistent cold is especially rare down here.

And like you said, no signs of it abating anytime soon. In fact the few days after this storm might be our warmest for a while. I'm betting people who hate cold and snow have been absolutely miserable this year. I hope their misery continues

It's a shame this storm is lacking cold air but it's not our last chance it would appear which should ease the pain of most. Hopefully what happens after day 7 will make everyone happy.

well on the warm part of the forecast they were wrong for sure, but the dry part still holds so far, esp. here in the Carolinas, and looking at the precip maps across the country, its off to a dry start to Winter overall. I guess it just seems wet since we're getting so much snow and ice. I'm sure I'll have another double digit departure this year...wouldn't want the last 10 to go all stag.

I know its a moot point, but on my winter outlook on the other board I mentioned how the NAO cycle might be repeating starting last year, and that could throw a monkey wrench in the temp forecast. Guess it really did.

Since Dec 1st

GSP 2.85"

CLT 2.71"

AVL 2.56"

RDU 3.22"

FAY 2.15"

GSO 2.87"

AHN 4.22"

ATL 3.49"

[triadwx]

Btw, NAM is out to 27..just thought I'd throw it out there..

[eyewall]

You can never just look at 850 temps and declare rain or snow. That is one sliver of the column the precipitation has to fall through. In this scenario, most of the models have shown the most warming below this level, so even if 850s are below freezing, it is still likely above freezing below this layer, and if it is 2 or 3C it is going to be very tough to melt that out.

1000-850mb partial thicknesses are a much better tool to look at in this situation, because they depict the layer-average temperature from 1000 to 850mb. If the thickness is 1300m or below, then the layer-avg temp is below 32F, and theoretically supportive of snow in the lower level, which is mainly what is in question here. You can also look at the 850-700mb thickness, but in this instance the mid-levels are not of as much concern.

Very true and this is actually pointed out in the new Christmas Storm case study posted by RAH. For southern areas it was rain on Christmas day because of a warm BL below 850.

[Wow]

You can never just look at 850 temps and declare rain or snow. That is one sliver of the column the precipitation has to fall through. In this scenario, most of the models have shown the most warming below this level, so even if 850s are below freezing, it is still likely above freezing below this layer, and if it is 2 or 3C it is going to be very tough to melt that out.

1000-850mb partial thicknesses are a much better tool to look at in this situation, because they depict the layer-average temperature from 1000 to 850mb. If the thickness is 1300m or below, then the layer-avg temp is below 32F, and theoretically supportive of snow in the lower level, which is mainly what is in question here. You can also look at the 850-700mb thickness, but in this instance the mid-levels are not of as much concern.

Very informative post many here need to read. BTW, welcome to the forums!

[triadwx]

@33 - Low forming in gulf, the freezing line is retreating fast. This run looks a bit slower than the 12z run, but really don't care to compare them..

[Lookout]

I disagree about Georgia on the Euro- if the upper low takes the track the Euro has, some lower elevations especially in NW GA maybe down to the northern ATL suburbs would get a few hours of snow and maybe a couple inches especially on the bushes/grassy surfaces. With strong dynamic cooling the actual 850 temps may end up colder than progged IF the upper/mid level low goes far enough south. Some areas farther south could see this scenario: Mostly rain, then at peak omega time a burst of heavy snow for an hour or two, then back to rain again. This could be very localized. Now if the upper low goes a bit farther north it is a moot point, GA except the peaks gets all rain. We will not totally get a handle on that for another day of two probably.

It seems strange for me to be on the pessimistic side and you on the optimistic one lol. But I just don't see it, although I have said that northwest ga might have a better chance than anywhere else (not counting mountains). I would be utterly shocked if a changeover got down to atlanta, much less any accumulation, but I have said also that those under the most intense area of the deformation axis could briefly switch to snow for a few hours but it's going to be very localized if it happens. However, The euro to me does not look impressive for north ga in general for this to happen since it doesn't appear as intense as some of the runs of the gfs/nam. It only drops 0.25 at best after 850s go barely below freezing. I doubt that cuts it.

What will be important to watch imho, is how soon and strong that deformation axis is to the west before it gets here. If it's intense enough, it could bring along it's own pocket of cold air and this pocket of cold air could be enhanced as the comma head intensifies. It's going to have to be really impressive though since boundary layer temps are so warm. If we were talking about boundary layer temps of 33 or 34, I would be much more bullish but models showing temps in the upper 30s/near 40 not only at the surface but up to 900 to 950mb. That is high and deep enough to make me believe it's unlikely for most. It really would take a lot to overcome that.

It's not unheard of though. I've seen some systems in the plains do this as I normally follow such events. A number of times I've seen locations be near 40 and rain one hour and the next hour they are 34 and heavy snow. This happens a lot in the spring time especially but normally the lowest 1500 feet is normally colder than what is being advertised here.

It's not a given yet the deformation axis/comma head will organize itself enough or even track over north Ga in a fashion that would favor such a scenario. We'll see I guess and I would love to be wrong and you be right. But remember this, when it comes to the southeast if it's not obviously apparent and you have to hunt for ways for it to snow, normally it doesn't work out. I saw DT say this 10 years ago and boy has it been right most of the time.

[ATL_Militarypolice]

Saw this posted on another forum.

Bad news from the NWS HQ, they've sent an administrative message indicating there are a lot of missing obs from the upper air balloon release today throwing a real wrench in forecasting models. Two of the sites AWOL are Peachtree City, GA and Birmingham, AL. This means if today's model cycles show big changes we won't know if its significant or a result of bad data ingest. Thankfully, there is time for them to fix it before we get to Wednesday.

http://wsbradio.com/blogs/kirk_mellishs_weather_commentary/

Here's the official message.

SENIOR DUTY METEOROLOGIST NWS ADMINISTRATIVE MESSAGE

NWS NCEP CENTRAL OPERATIONS CAMP SPRINGS MD

1343Z SUN JAN 23 2011

THE 12Z NAM BEGAN ON SCHD AND THERE WERE MORE THAN

USUAL RAOB PBLMS OVER N AMER BUT WITH 29 CAN 11 MEX

AND 8 CARIB RAOBS AVBL. RAOB RECAP...

AKN/70326 - POWER FAILURE...CODE 10144.

FFC/72215 - FLIGHT EQUIPMENT FAILURE...CODE 10158.

KPP/78970 - GROUND EQUIPMENT FAILURE...CODE 10142.

NCC/78988 - GROUND EQUIPMENT FAILURE...CODE 10142.

MZL/76654 - MISCELLANEOUS ISSUE...CODE 10159.

BMX/72230 - SHORT TO 472 MB...CODE 10159.

INL/72747 - WIND DATA MISSING.

YMW/71722 - UNAVAILABLE.

YVP/71906 - DEL HGTS/TEMPS 871 MB AND UP...UP TO 6 K WARM.

LIH/91165 - DELETED TEMPS 841-774 MB...SUPER-ADIABATIC LR.

KPB/78954 - DELETED TEMPS 890...715-704...674-672 MB...

SUPER-ADIABATIC LAPSE RATES.

CRITICAL WEATHER DAY STATUS...

NO CWD IS IN EFFECT PRESENTLY HOWEVER NWS WILL BE

MONITORING THE DEVPMT OF A POTENTIALLY MAJOR EAST

COAST WINTER STORM OVER THE NEXT FEW DAYS.

$$

STOUDT/SDM/NCO/NCEP