Christmas Storm II

[Wow]

Near closed contour at 72...

[Cameronfry]

I would take 1-2. My mom is terminally I'll with ovarian cancer and she has never seen a white Christmas here in nega ( Athens ). I'm not picky.

Prayers and best wishes to your family.

[beanskip]

Yikes -- the low off the NE coast much farther SW at 72 hours vs. 78 on the 18z NAM -- like HUNDREDS of miles.

[beanskip]

Then tYvm.

Incorrect... X is a local maximum in vorticity and N is a local minimum

[FoothillsNC]

the x is cyclonic flow , the n is anticyclonic flow. Don't worry about that though. At 78 hours and beyond, its doing about what I had thought might happen. Closing off. Not quite there yet, but its as close as possible with out actually being. I still think this may be a bowling ball from the start in LAX area. That wouild have good side and bad side to it. At 84, its in estern KS, and the eastern US vortex is pulling away some.

[tarheelwx]

I'm not certain this thing couldn't go too far south or end up suppressed. I hope not, but have seen it happen before.

TW

[rduwx]

the x is cyclonic flow , the n is anticyclonic flow. Don't worry about that though. At 78 hours and beyond, its doing about what I had thought might happen. Closing off. Not quite there yet, but its as close as possible with out actually being. I still think this may be a bowling ball from the start in LAX area. That wouild have good side and bad side to it. At 84, its in estern KS, and the eastern US vortex is pulling away some.

If it's a bowling ball moving across the US what is going to stop it from going north or even a lakes cutter? I usually hate seeing that because I instantly start thinking lakes cutter.

[WeatherNC]

Near closed contour at 72...

It is closed on NCEP at 72 hrs, but opens back up at 78. And I do not see any indication thus far of a phase like the GFS showed around 102hrs on the 12z run.

[BIG FROSTY]

the x is cyclonic flow , the n is anticyclonic flow. Don't worry about that though. At 78 hours and beyond, its doing about what I had thought might happen. Closing off. Not quite there yet, but its as close as possible with out actually being. I still think this may be a bowling ball from the start in LAX area. That wouild have good side and bad side to it. At 84, its in estern KS, and the eastern US vortex is pulling away some.

So this would beget a northward trend right ?

[BullCityWx]

There's about 50 miles difference between the NAM and Euro at hour 84/96 from their last respective runs(the NAM being further NE).

[UpStateCAD]

I'm not certain this thing couldn't go too far south or end up suppressed. I hope not, but have seen it happen before.

TW

I was starting to worry about that as well today when every new run seemed to be more and more south.

[CaryWx]

the x is cyclonic flow , the n is anticyclonic flow. Don't worry about that though. At 78 hours and beyond, its doing about what I had thought might happen. Closing off. Not quite there yet, but its as close as possible with out actually being. I still think this may be a bowling ball from the start in LAX area. That wouild have good side and bad side to it. At 84, its in estern KS, and the eastern US vortex is pulling away some.

This is what bothers me the most about any potential with this storm...Moreso than suppression/none-phasing

[beanskip]

Looks like the surface low at 84h would place somewhere around DFW??? I can live with that.

[buckeyefan1]

Incorrect... X is a local maximum in vorticity and N is a local minimum

Oops! Thank you for the correction

[FoothillsNC]

it probably cant' get too far south because of the closed ridge int eh Gulf of Mexico. It may actually have to ride completley around that ridge. Weird to have a ridge in the gulf, but you can clearly see it. I think this will end up being either a very sharp trough or a small bowling ball upper low that follows the flow. Theres not much moisture being drawn at all from teh Gulf, so far its going to be dropping what occurs that it brings with it, and what the "spin" or vorticity can get shaken out of it. Those can be good precip makers, or not so good. The futher south, the better. I hate seeing the Gulf shut off so far, but later on I guess it will be open more. We'll see what the Euro has. If its even futher south, that would help to create more moisture. The amounts look really light on the NAM , but thats to be expected with this track and not a huge open trough. So this so far looks like probably the best snow right under it and northeast of the track. The moisture in the high plains around SD and Iowa will dissipate later on and is produced from the overrunning of pacific moisture hitting the high pressure. From this point the Upper low or trough should start to migrate more southeastward with time, thanks to the east coast big offshore vortex.

[tnweathernut]

It's looking more and more like the Pacific is going to cooperate for us. The next BIG thing we will have to worry about is the block and whether it holds its ground or starts to leave early (as Robert noted). If this happens it will be a case of the Pacific finally giving us what we need and the Atlantic not. I certainly hope the block can maintain and force this bowling ball to come through the deep south.

[NCSNOW]

If this model run went out another 24 hours, Id be willing to bet with the flow looking the way it does our storm would be in central to south AL/GA on its way to the big pond and hopefully closing back off, pausing rephasing and going negative tilt before heading OTS. Pretty good consistency from the Nam on its runs today. Gonna wait on the ukie and crazy uncle tonight. Lord only knows what the GFS will spit out. Thanks Robert,WOW & NC WEATHER.

[NCwxMAN]

OK, here's a weeine question if there ever was one -- what's the difference, if any, between an "N" and an "X" on the 500mb vort charts?

Its a great question for I once wanted to know the same thing and HEY we all started out not knowing, but anyway X marks a vorticity maximum and that means the area with the highest vorticity and ahead of that X is divergence (or rising air motion) N is a vorticity minimum or area where air is sinking and marks areas of high pressure mostly just right of the N. Hope this helps you understand.

[Weather Czar]

it probably cant' get too far south because of the closed ridge int eh Gulf of Mexico. It may actually have to ride completley around that ridge. Weird to have a ridge in the gulf, but you can clearly see it. I think this will end up being either a very sharp trough or a small bowling ball upper low that follows the flow. Theres not much moisture being drawn at all from teh Gulf, so far its going to be dropping what occurs that it brings with it, and what the "spin" or vorticity can get shaken out of it. Those can be good precip makers, or not so good. The futher south, the better. I hate seeing the Gulf shut off so far, but later on I guess it will be open more. We'll see what the Euro has. If its even futher south, that would help to create more moisture. The amounts look really light on the NAM , but thats to be expected with this track and not a huge open trough. So this so far looks like probably the best snow right under it and northeast of the track. The moisture in the high plains around SD and Iowa will dissipate later on and is produced from the overrunning of pacific moisture hitting the high pressure. From this point the Upper low or trough should start to migrate more southeastward with time, thanks to the east coast big offshore vortex.

Yeah if you look out ahead of it the flow is flatter. from 81 to 84 the qpf bumps up on my graphics and the northern branch has just entered NE Montana. Looks like our ridge is starting to build out west at 84 which should help drive in SE? Then a Gulf tap?

[snowlover91]

Did anyone notice how the NAM shows a 1080mb high way up north? I believe that's our block, not sure how that would impact things but GFS only shows a 1056mb high in the same area so thats a big difference in strength.

[FoothillsNC]

if you loop the 700 rh and VV you can see the sudden increase in precip in Ark and eastern Ok, and heading for Tenn and Ky. That should really light up quickly, probably already has the NAM is hinting at it. A fun system to watch unfold and unusual...but it does remind me of the Feb 2004 system with the basic track across the midsouth, from well out west. I also think its going to be hard to get this to go up the east coast with that huge vortex still in the way, unless it weakens suddenly or a sharp ridge pops out west. Both of these would help us a little , I think it would sharpen the trough more, turn it neg tilt some, as opposed to shearing it (which is probably still possible though) and then the fun begins right after 84 for Tenn, Ky and northern Miss.

[Weather Czar]

RGEM at 48 " dig baby dig"

http://www.weatheroffice.gc.ca/data/model_forecast/520_100.gif

[Rankin5150]

if you loop the 700 rh and VV you can see the sudden increase in precip in Ark and eastern Ok, and heading for Tenn and Ky. That should really light up quickly, probably already has the NAM is hinting at it. A fun system to watch unfold and unusual...but it does remind me of the Feb 2004 system with the basic track across the midsouth, from well out west. I also think its going to be hard to get this to go up the east coast with that huge vortex still in the way, unless it weakens suddenly or a sharp ridge pops out west. Both of these would help us a little , I think it would sharpen the trough more, turn it neg tilt some, as opposed to shearing it (which is probably still possible though) and then the fun begins right after 84 for Tenn, Ky and northern Miss.

It will be interesting to see if the 00z GFS op sticks to it's guns...

[farleydawg79]

Prayers and best wishes to your family.

Thanks to all for the kind thoughts.... Now let's get this thing to dig baby dig

[FoothillsNC]

Does it continue to show its northerly track or will it make a southward shift? That's all one could question about it lol.

I'll be surprised if it hasn't shifted south somewhat.

[Gastonwxman]

hr. 30: The shortwave looks as though it wants to dig into central California, but it may go a little further south than that.

[snowlover91]

Hour 42 the shortwave is at the southern tip of CA.

[Lookout]

I don't mean to sound like a prick but some people seem to have a reading comprehension problem. A few pages back, I posted this.

Guys I know it's tempting and easy to get off track, I've been guilty of it myself, but let's try to keep this off topic stuff out of the thread. The main reason for that is if we don't cut back on the off topic chatter, you end up with a long thread where people have to search to find posts relative to the topic of the thread. We need to keep this thread focused only on this christmas system and leave the off topic chatter to the december thread.

We are now at the point where we have so many users visiting and posting in this thread that it's now a necessity to delete this type of stuff so the quality of the thread remains high. So just letting you know that off topic stuff in this thread will be deleted. Repeat offenders will also be given timeouts. We, myself included, are going to be pretty strict on this so please take my advice.

Now back to regular scheduled programming

Yet off topic posts and one sentence nonsense like "the gfs has started" continues. Indeed, I was completely ignored by a handful of people literally minutes after I posted that. I am dead serious about this, stop with the off topic stuff and silly one liners. If folks do not heed my warning, they will be taking a vacation

[KO0588]

A lot further south coming in

[Wow]

ahhh... we have a cut off low at 48 hrs. actually very simlar to the 0z Euro