Christmas Storm V

[burgertime]

Looking like the 6z GFS at 54 our low isn't as consolidated though and is stretched out a little right under La, Ms, and Al.

[SnowNiner]

Oh the tension!!! Thread the needle please!! Maybe GFS is catching on to reality....strong southern system, not so easy to break apart by northern system. It's like the Civil War of snow storms. The south is STRONG, but eventually they phase together, get along, and make good things. I'm sorry what were we talking about? NAM that's right.....proceed.

[strongwxnc]

Looks like it is trying to phase at 54

L is in SW Al at this time.

[NCSNOW]

Looks like a pos tilt at 48 ? little slower ?

I'm behind you guys, but at 42 if the trough would just get neutral, the northern stream could drop the egg right in the basket and we'd be saying BOOM>

[FoothillsNC]

it looks like the first northern stream s/w misses it and it remains pretty healthy in Louisiana, then it rolls acros the Gulf coast slowly as the northern stream begins to retrograde a little bit with more energy continuously coming down . This is probably shearing the top of our southern stream off a little bit. So its not a good phase if any so far, the two streams remain separate becuase the northern stream isn't digging well enough.

[ST21]

looks a little warmer but stronger so far.

[burgertime]

Yea this one was ever so close but looks like it just barely misses. @66 our low never bombs out and it's just off the coast of CHS. Looks like less moisture then the 6z.

[burgertime]

@72 it's pulling away....on to the Euro.

[Carvers Gap]

it looks like the first northern stream s/w misses it and it remains pretty healthy in Louisiana, then it rolls acros the Gulf coast slowly as the northern stream begins to retrograde a little bit with more energy continuously coming down . This is probably shearing the top of our southern stream off a little bit. So its not a good phase if any so far, the two streams remain separate becuase the northern stream isn't digging well enough.

Foothills, is there a chance this is not being modeled well just due to complex nature of the sw interaction? Seems like it is getting late in the game for major changes, though...

[burgertime]

Foothills, is there a chance this is not being modeled well just due to complex nature of the sw interaction? Seems like it is getting late in the game for major changes, though...

I believe these are never modeled well, just look at last week. However this is a very plausible solution.

[FoothillsNC]

The models always have a hard time with phasing and interacting. But the run did keep a strong southern stream the whole trip, it just didn't phase with the northern stream, I do think anything is still possible and the models could easily be mishandling whats going to happen. As it stands with this GFS run, the gulf low allows some light snow in n. Georgia and the wstern Carolinas but not much, really its flurries. Futher south in middle GA and the eastern Carolinas are closer to the better moisture and dynamics so they may get a little more snow, but again the model could easily be mishandling the interaction completely, which would make a big difference.

[strongwxnc]

Yea.

This run is direr than the 06 run as the L is also a touch due east.

[Wow]

Looking pretty grim right now. Hopefully the 12z Euro kicks back to its solution of a perfect phase. I reallly hoped the GFS/GGEM would've begun to see it by now. They may be right, though.

[SnowNiner]

12Z Euro is our last stand. Wow. This time yesterday we were flying high. Now, a tailspin.

[Carvers Gap]

I believe these are never modeled well, just look at last week. However this is a very plausible solution.

Definitely plausible - maybe likely solution. In TN, there have been numerous times where an apparent phase or partial phase backed off at the last minute. It seems that scenario plays out more in December in TN than other months. We just don't get much snow here in December. Climatology argues against it. At KTRI right now, I think they have four inches. That's pretty good here in December. Anything else is just bonus.

Edit: Seems like in 1989 I was driving home from college in December under a winter storm warning. It never snowed, but was very cold. I think that was a strong La Nina winter?

[UNCCmetgrad]

The models always have a hard time with phasing and interacting. But the run did keep a strong southern stream the whole trip, it just didn't phase with the northern stream, I do think anything is still possible and the models could easily be mishandling whats going to happen. As it stands with this GFS run, the gulf low allows some light snow in n. Georgia and the wstern Carolinas but not much, really its flurries. Futher south in middle GA and the eastern Carolinas are closer to the better moisture and dynamics so they may get a little more snow, but again the model could easily be mishandling the interaction completely, which would make a big difference.

I'm impressed with the southern stream system as it really stays intact until the very end. Its just that with all that energy strung out in the northern stream, they cannot properly phase in time.

[FoothillsNC]

for the western Carolinas outside the mountains and into the western piedmont region, if you're going to bet any snow from this it will have to allow more interaction starting further west. What this run does is allow a northern stream to blast through here totally dry, and leave the Gulf system down there slowly heading east. We won't get any moisture from the Gulf system becuase the westerly winds have already reached us. And when it goes up the coast we won't get any precip back here, not even close really, becuase theres now strong backing of the winds, so what we're left with on this run is a trace event. This probably is going to be a big event or a nothing / trace event here.

[UpStateCAD]

The models always have a hard time with phasing and interacting. But the run did keep a strong southern stream the whole trip, it just didn't phase with the northern stream, I do think anything is still possible and the models could easily be mishandling whats going to happen. As it stands with this GFS run, the gulf low allows some light snow in n. Georgia and the wstern Carolinas but not much, really its flurries. Futher south in middle GA and the eastern Carolinas are closer to the better moisture and dynamics so they may get a little more snow, but again the model could easily be mishandling the interaction completely, which would make a big difference.

Didn't I see it posted here within the last week or so that there is one particular model that handles phasing situations much better than the rest? And I don't think it was the Euro. What model is that?

[SBUWX23]

UKMET is again further east.

[Shawn]

At least part of the difficulty in predicting the evolution of this storm was related to the forecasts of the evolution of the upper pattern. A short wave over the southeast carved out a strong upper low that moved up the east coast as opposed to the earlier solutions of a weaker wave passing well off the coast. -Noaa, Blizzard of 2000

[strongwxnc]

KGSP

.SHORT TERM /FRIDAY THROUGH SUNDAY/...

-- Changed Discussion --AS OF 1030 AM THURSDAY...A FEW ADDITIONAL MODEL DETAILS ARE STARTING

TO EMERGE WITH REGARD TO THE SAT/SAT NIGHT SOLUTIONS. THE AVAILABLE

00Z/06Z MODELS...ALONG WITH THE NEWLY ARRIVED 12Z NAM...ARE STARTING

TO CONVERGE SLIGHTLY ON A FAIRLY QUICK HIT OF THE INITIAL WAVE OF

PRECIPITATION WITH THIS SYSTEM ON SAT AS THE DEVELOPING SURFACE LOW

BEGINS TO TRANSIT THE NRN GULF OF MEXICO. THIS SHOULD RESULT IN

MAINLY LIGHT SNOW DEVELOPING FROM W TO E DURING THE DAYTIME IN MOST

AREAS...WITH WEAK FRONTOGENESIS ALONG THE BAROCLINIC ZONE ACROSS THE

REGION. THE MAIN MODEL DIFFERENCE AT THIS POINT IS THAT THE 00Z

ECMWF DEVELOPS A NRN TIER CLOSED LOW OVER INDIANA MIDDAY SAT...WHILE

THE NAM/GFS/GEM/GEFS AND SREF ARE ALL FARTHER NE WITH THE NRN TIER

H5 LOW CENTER...AND NOT AS DEEP. THIS ALLOWS THE ECM SFC LOW TO

DEEPEN MORE STRONGLY THAN IN THE OTHER MODELS AS IT HUGS THE SE

COAST SAT NIGHT. ALTHOUGH THE ECM HAS BEEN FAIRLY CONSISTENT FROM

RUN TO RUN THE PAST SEVERAL DAYS...TIME LAG TRENDS SHOW A SLIGHTLY

FASTER PROGRESSION OF THE GULF SFC LOW ON SAT...AND A CORRESPONDING

SLIGHT EASTWARD SHIFT IN THE HEAVIER STRIPES OF QPF. THE 06Z GFS

ALSO HUGS THE COAST...BUT IS LESS DEEP THAN THE ECM...WHILE THE

NAM/GEM/SREF HAVE A MORE OFFSHORE SOLUTION WITH LESS INLAND QPF.

WILL AWAIT THE FULL SUITE OF 12Z MODEL GUIDANCE BEFORE MAKING ANY

DECISION ON WINTER STORM WATCHES...HOWEVER...THE FOLLOWING TRENDS

ARE EMERGING. LIGHT SNOWFALL WILL LIKELY SPREAD INTO THE REGION FROM

THE WEST ON SATURDAY WITH THE INITIAL ROUND OF MOISTENING AND WEAK

FRONTOGENESIS. THE MAIN THREAT AREA FOR HEAVY SNOW COULD THEN SHIFT

TO THE PIEDMONT AS DEFORMATION ZONE FORCING INCREASES NW OF THE

PASSING COASTAL LOW SAT NIGHT. THIS COULD INCLUDE THE CHARLOTTE

AREA. THE DURATION THREAT FOR HEAVY SNOW WOULD THEN SHIFT TO NW FLOW

ACCUMULATIONS NEAR THE TN BORDER IN THE WRN MOUNTAINS SUN/SUN NIGHT.

MORE DETAILS WILL FOLLOW IN THE FULL AFTERNOON SHORT TERM DISCUSSION.-- End Changed Discussion --

[Jon]

Quote

At least part of the difficulty in predicting the evolution of this storm was related to the forecasts of the evolution of the upper pattern. A short wave over the southeast carved out a strong upper low that moved up the east coast as opposed to the earlier solutions of a weaker wave passing well off the coast. -Noaa, Blizzard of 2000

Good quote...I feel like we won't have a hold on things, again, by 48hrs out. I can still see the NAM and GFS not agreeing by then, and the Euro out to lala land, regardless if it shows a big storm or not. These potentially historic storms are so hard to forecast correctly, I'd hate to have the responsibility of a TV met right now...hopefully they can get it right, I wouldn't mind a surprise like 2000 though.

[burgertime]

Didn't I see it posted here within the last week or so that there is one particular model that handles phasing situations much better than the rest? And I don't think it was the Euro. What model is that?

I believe it was the UKMET that handles the phases better, but it's saying NO right now.

[dsaur]

The models always have a hard time with phasing and interacting. But the run did keep a strong southern stream the whole trip, it just didn't phase with the northern stream, I do think anything is still possible and the models could easily be mishandling whats going to happen. As it stands with this GFS run, the gulf low allows some light snow in n. Georgia and the wstern Carolinas but not much, really its flurries. Futher south in middle GA and the eastern Carolinas are closer to the better moisture and dynamics so they may get a little more snow, but again the model could easily be mishandling the interaction completely, which would make a big difference.

It is painful to see the cold air so late to the party...

The one thing that sticks out to me is the fact central Ga. stays in the game when all else is crumbling. The gulf low is a constant, and as long as a low is in the gulf, all solutions still seem possible, to include phasing. May be a now cast, but at least the low hasn't come up into central Ga. like earlier runs. And if all else fails we could have some good blocking for the next system. T

[tgarren]

Quote

At least part of the difficulty in predicting the evolution of this storm was related to the forecasts of the evolution of the upper pattern. A short wave over the southeast carved out a strong upper low that moved up the east coast as opposed to the earlier solutions of a weaker wave passing well off the coast. -Noaa, Blizzard of 2000

Good quote...I feel like we won't have a hold on things, again, by 48hrs out. I can still see the NAM and GFS not agreeing by then, and the Euro out to lala land, regardless if it shows a big storm or not. These potentially historic storms are so hard to forecast correctly, I'd hate to have the responsibility of a TV met right now...hopefully they can get it right, I wouldn't mind a surprise like 2000 though.

from what i have read i thought no model at any point ever showed the phase occurring soon enough in 2000? slightly different situation here. but i eagerly await the 12z euro for my last glimmer of hope.

[NCSNOW]

Well the southern stream will be there. Like GSP said its how the models handle the northern stream thats gonna dictate how things unfold. So thats where all eyes will have to turn now to see if the nam/gfs are to progressive or if the euro last night had it right. Right now I'm hugging the 12z euro, hoping it doesn't come in as progressive with the northern stream. Be interesting to see the ensembles and see if we can pinpoint why the gfs is given us the presentation it is in regards to northern stream. Maybe it has the 50/50 in a different position, allowing for the northern stream to behave this way.

[Shawn]

from what i have read i thought no model at any point ever showed the phase occurring soon enough in 2000? slightly different situation here. but i eagerly await the 12z euro for my last glimmer of hope.

I'm not too sure how good of a comparison that system is to this one, but really.. some of the similarities are scary if you look at the upper air etc.

[Rankin5150]

EDIT: this thing is far from over. We may not see a blockbuster, epic event but we at still in th game...

KGSP

.SHORT TERM /FRIDAY THROUGH SUNDAY/...

-- Changed Discussion --AS OF 1030 AM THURSDAY...A FEW ADDITIONAL MODEL DETAILS ARE STARTING

TO EMERGE WITH REGARD TO THE SAT/SAT NIGHT SOLUTIONS. THE AVAILABLE

00Z/06Z MODELS...ALONG WITH THE NEWLY ARRIVED 12Z NAM...ARE STARTING

TO CONVERGE SLIGHTLY ON A FAIRLY QUICK HIT OF THE INITIAL WAVE OF

PRECIPITATION WITH THIS SYSTEM ON SAT AS THE DEVELOPING SURFACE LOW

BEGINS TO TRANSIT THE NRN GULF OF MEXICO. THIS SHOULD RESULT IN

MAINLY LIGHT SNOW DEVELOPING FROM W TO E DURING THE DAYTIME IN MOST

AREAS...WITH WEAK FRONTOGENESIS ALONG THE BAROCLINIC ZONE ACROSS THE

REGION. THE MAIN MODEL DIFFERENCE AT THIS POINT IS THAT THE 00Z

ECMWF DEVELOPS A NRN TIER CLOSED LOW OVER INDIANA MIDDAY SAT...WHILE

THE NAM/GFS/GEM/GEFS AND SREF ARE ALL FARTHER NE WITH THE NRN TIER

H5 LOW CENTER...AND NOT AS DEEP. THIS ALLOWS THE ECM SFC LOW TO

DEEPEN MORE STRONGLY THAN IN THE OTHER MODELS AS IT HUGS THE SE

COAST SAT NIGHT. ALTHOUGH THE ECM HAS BEEN FAIRLY CONSISTENT FROM

RUN TO RUN THE PAST SEVERAL DAYS...TIME LAG TRENDS SHOW A SLIGHTLY

FASTER PROGRESSION OF THE GULF SFC LOW ON SAT...AND A CORRESPONDING

SLIGHT EASTWARD SHIFT IN THE HEAVIER STRIPES OF QPF. THE 06Z GFS

ALSO HUGS THE COAST...BUT IS LESS DEEP THAN THE ECM...WHILE THE

NAM/GEM/SREF HAVE A MORE OFFSHORE SOLUTION WITH LESS INLAND QPF.

WILL AWAIT THE FULL SUITE OF 12Z MODEL GUIDANCE BEFORE MAKING ANY

DECISION ON WINTER STORM WATCHES...HOWEVER...THE FOLLOWING TRENDS

ARE EMERGING. LIGHT SNOWFALL WILL LIKELY SPREAD INTO THE REGION FROM

THE WEST ON SATURDAY WITH THE INITIAL ROUND OF MOISTENING AND WEAK

FRONTOGENESIS. THE MAIN THREAT AREA FOR HEAVY SNOW COULD THEN SHIFT

TO THE PIEDMONT AS DEFORMATION ZONE FORCING INCREASES NW OF THE

PASSING COASTAL LOW SAT NIGHT. THIS COULD INCLUDE THE CHARLOTTE

AREA. THE DURATION THREAT FOR HEAVY SNOW WOULD THEN SHIFT TO NW FLOW

ACCUMULATIONS NEAR THE TN BORDER IN THE WRN MOUNTAINS SUN/SUN NIGHT.

MORE DETAILS WILL FOLLOW IN THE FULL AFTERNOON SHORT TERM DISCUSSION.-- End Changed Discussion --

[Jon]

from what i have read i thought no model at any point ever showed the phase occurring soon enough in 2000? slightly different situation here. but i eagerly await the 12z euro for my last glimmer of hope.

I didn't say it did. What I'm saying, as shown in the quote, that there was a ten fold difference in what it did and what it didn't do...my point was, as everyone in this forum knows, that the models are having a hard time with the idea of phasing and timing, and even the strength of the low as it makes it's way from Az. Models are starting to show a lesser solution, and everyone is freakin out. I still think we have a chance here, this is guidance, not truth. The 2000 storm is not analogous (to me) if that's what you thought I was saying.

[SnowNiner]

I can't believe with all this dissecting and discussion, the TV mets around here had it right for the last two days. I kept hearing a "postcard" event, "minor burst", dusting, 1-2 inches the last two days. I thought they were crazy with what the EURO was continuing to show and how the GFS was trending. Seems like they're not so bad afterall. I guess I need to start listening.