Ending out December with a Potential Pattern Change

[NEK_VT_Upslope_Event]

Ski areas know how to deal with it. It happens almost every year it seems. Heck it rained twice last holiday break. Nothing different from any other Christmas week, lol.

Luckily this isn't 1989, and grooming and snowmaking can recover it in a couple days for the majority of the folks. The real trick is what it is 2-3 days after Xmas. That's when it gets real busy, so having this come in earlier would be better.

Also, almost every cutter is usually followed within 2-3 days max by a front or an upslope event, and once 2-3" of freshies are on the ground the rain is a distant memory. It doesn't take much to change the conditions, and the mood, in a northern resort town.

[Ginx snewx]

<32F doesn't equal frigid cold IMO

<32 equals ice , lock that up, schuss schuss scrape schuss schuss scrape lol. I hope not for my kins sake

[Ginx snewx]

Also, almost every cutter is usually followed within 2-3 days max by a front or an upslope event, and once 2-3" of freshies are on the ground the rain is a distant memory. It doesn't take much to change the conditions, and the mood, in a northern resort town.

again the post was about Christmas day not that week and man I hope it dumps all week on massive up slope as it looks it could

[forkyfork]

Wow, wait until the tropical tidbits 18z GFS 500 anomalies comes out. Just textbook.

the euro ens hold on to a -ao, -epo, and -nao til the end of the run, though the -nao weakens somewhat at the tail end

[CoastalWx]

the euro ens hold on to a -ao, -epo, and -nao til the end of the run, though the -nao weakens somewhat at the tail end

 

Yeah, but not too bad though. We'll see if we can continue with that, esp if any lows really blow up as they pass our longitude. 

[CoastalWx]

Pretty cool. You can see how after it weakens, another ULL moves up and forces more heights to build and push the PV southwest again at the end of the run. Just remember this is just an example of how it could work out, I would never take the op verbatim..but a nice example of the dynamics at play.

 

http://www.tropicaltidbits.com/analysis/models/?model=gfs&region=nhem&pkg=z500a&runtime=2014121718&fh=90

[powderfreak]

Ice sucks, you know it I know it, sketchy is sketchy but I was talking about Christmas day, I know a lot of my peeps are going away this Christmas.

Oh yeah, the first day after a rain/thaw is like a punt day. The groomers can't really work their magic because you still have wet snow under the surface, so you need another night or so to really lock it up, then till it out. By the third day you've put it back together for at least decent sliding on groomed trails.

And like NEKingdom said, even 2-3" (fluff or not) makes a huge difference in surface conditions once that gets groomed in. So we just pray it snows behind any grinch system. I'd assume a massive cut off like that would being some upslope, even if it's westerly flow streamers from the Lakes.

[RUNNAWAYICEBERG]

Yea, that's a pretty cool looking run.

[powderfreak]

Pretty cool. You can see how after it weakens, another ULL moves up and forces more heights to build and push the PV southwest again at the end of the run. Just remember this is just an example of how it could work out, I would never take the op verbatim..but a nice example of the dynamics at play.

http://www.tropicaltidbits.com/analysis/models/?model=gfs&region=nhem&pkg=z500a&runtime=2014121718&fh=90

Just make sure to let those turn the corner and come up the coast and we are all set.

Wouldn't even mind a little SE ridge like snowgoose mentioned.

[CoastalWx]

Just make sure to let those turn the corner and come up the coast and we are all set.

Wouldn't even mind a little SE ridge like snowgoose mentioned.

 

I was waiting for that comment. I wouldn't sweat those details.

[powderfreak]

I was waiting for that comment. I wouldn't sweat those details.

Haha. Not sweating them, just musing and talking a loud like everyone else on the good signals going forward. I've heard theSE ridge mentioned a couple times by mets, not always a bad thing. I'm not feeling a uber-suppressed pattern so I think it looks great going forward. Blocking may be hit or miss, and the trough axis looks far enough west in the means to avoid every single piece of energy from going dead east off the mid-Atlantic coast.

[tavwtby]

You do have to wonder though.. What is it about that timeframe that makes the atmosphere produce a cutter almost every year. And it's not bad luck as some like to say

Solstice???

[TheSnowman]

OK has Anyone ever seen what happens in the 180H area of the 18z GFS??  A Low goes Well west of us and then Explodes over Buffalo down into the 960's and even the though the precip. is Past us it Re-expands back down south as snow?  Strangest thing I may have seen on a model that close.  As the storm comes in, that 850 0C line has Well north of Toronto above freezing and Northern FL below it as it loops up.  

[Neblizzard]

Holy Moly does that turn the atmosphere inside out over in the EPO and NAO regions. Wow.

Looks awesome. Sometimes you gotta lose the battle to win the war. Let's hope we get a massive nuke ripping west of us Christmas eve. That block over the Davis Straights is just insane. It shakes hands with the -EPO forming a ridge bridge...classic.

[Typhoon Tip]

Talked to HM about that yesterday. Even at 50mb it's showing signs of elongation and splitting near North Pole. Granted it's been "bend don't break" lately but a nice sign hopefully.

Four days ago I posted the CPC's GFS, 10mb temperature anomaly product for D10, and it showed a new, small node of positive anomaly over the northern Eurasian side...

 

Now that the interval in question is D6, it's conserved...and the D7-10 show it growing off the charts.  I chose that very high sigma level because from my own studies ... SSWs tend to first emerge at these extreme altitudes, then growing in mass as the propagation (downwelling) ensues. 

 

We'll see where this one is going.. As of right now, the 30mb level is not detecting it just yet, but that's about right as far as standardized timing.  Should/could see the 30mb start flashing out around D9 and 10 within a day or two of cycles, then a week later 50mb gets involved. ..and so on.  This would all fit nicely inside the temporal bell-curve from the historic files going back to 1979. Most SSW's due tend to kick off between Xmass and the first couple of weeks of the New Year.  It takes them two weeks to tickle the tropopause... at which time the AO index responds.  The correlation is lagged..

 

Anyway, I'm curious what the ECM products are indicating, because the GEFs current vision has earmarks of SSW given to how intense and large this 10mb initial onset is taking place.

 

[CoastalWx]

Four days ago I posted the CPC's GFS, 10mb temperature anomaly product for D10, and it showed a new, small node of positive anomaly over the northern Eurasian side...

 

Now that the interval in question is D6, it's conserved...and the D7-10 show it growing off the charts.  I chose that very high sigma level because from my own studies ... SSWs tend to first emerge at these extreme altitudes, then growing in mass as the propagation (downwelling) ensues. 

 

We'll see where this one is going.. As of right now, the 30mb level is not detecting it just yet, but that's about right as far as standardized timing.  Should/could see the 30mb start flashing out around D9 and 10 within a day or two of cycles, then a week later 50mb gets involved. ..and so on.  This would all fit nicely inside the temporal bell-curve from the historic files going back to 1979. Most SSW's due tend to kick off between Xmass and the first couple of weeks of the New Year.  It takes them two weeks to tickle the tropopause... at which time the AO index responds.  The correlation is lagged..

 

Anyway, I'm curious what the ECM products are indicating, because the GEFs current vision has earmarks of SSW given to how intense and large this 10mb initial onset is taking place.

 

 

50mb on the EC almost wants to split it seems. It's elongated from north pole to Hudson Bay with that look where you could almost see a new center near Hudson Bay. I saw that earlier in November to no avail, but we will see where this goes as you said. Some warming near Iceland and NE Siberia too.

[Typhoon Tip]

50mb on the EC almost wants to split it seems. It's elongated from north pole to Hudson Bay with that look where you could almost see a new center near Hudson Bay. I saw that earlier in November to no avail, but we will see where this goes as you said. Some warming near Iceland and NE Siberia too.

 

Okay, ...so not an exact match; still, some subtleties in your description seem to suggest something is afoot. Sometimes these deals start that way, with instability appeals ... kind of like 'model fore tremors'  

[FRWEATHA]

Record cold in Siberia right now. -66. Does that get pushed to this side of the globe?

[Ginx snewx]

Record cold in Siberia right now. -66. Does that get pushed to this side of the globe?

ridge bridge riding the rails, we wait the details. Got my shades on tight just chillin it.

[Ginx snewx]

Now that I am home on my PC with access to everything, Christmas night looks pretty wild.

[kdxken]

How did the December 2012 cutter work out for changing the pattern?

 

"

Will a Storm Like This Help the Current Pattern?

Even though snow lovers cringe at the sight of a Great Lakes cutter in the Northeast, it actually helps them in a major way, with time. As the low pressure system intensifies, it begins to bring down cold air from Canada, and helps with the below normal snow pack of the U.S. currently. As it moves Northeast, it brings the cold air with it, and provides a gateway for colder air to stream down from Canada into the Midwest regions, and a part of the Northeast."

 

https://www.geoea.org/2012/12/10/midwest-great-lakes-cutter-then-what/

[Damage In Tolland]

Now that I am home on my PC with access to everything, Christmas night looks pretty wild.

Describe and circumscribe what your interpretation is

[Sey-Mour Snow]

OK has Anyone ever seen what happens in the 180H area of the 18z GFS??  A Low goes Well west of us and then Explodes over Buffalo down into the 960's and even the though the precip. is Past us it Re-expands back down south as snow?  Strangest thing I may have seen on a model that close.  As the storm comes in, that 850 0C line has Well north of Toronto above freezing and Northern FL below it as it loops up.  

I think that is just a glitch in the ncep page.. WSI and Weatherbell don't show that.. But i see what you are saying on the NCEP page.. Doesn't look right.. I think it shows 12 hour precip totals on the 180hr panel for some reason.  

[SR Airglow]

I'm seeing that strange expansion of precip to the south as well on meteocentre and Weatherbell, don't know what's causing it but it's very odd, can't say I've ever seen something like that verify before.

 

 

[HoarfrostHubb]

It's a Christmas miracle

[powderfreak]

I'm seeing that strange expansion of precip to the south as well on meteocentre and Weatherbell, don't know what's causing it but it's very odd, can't say I've ever seen something like that verify before.

Huh? We saw that with the last system. These things wrap up and rain to the north of the system and snow to the south of them. It's not uncommon in a big winter cut-off to cool the mid-levels sort of "all at once". So you go from a pounding heavy rain to dry slot then light snows and instability snow showers with the ULL overhead. It could be diurnally driven snow showers or the ULL moves in so you get a blossoming of light snows to the south of the occluded surface low.

[powderfreak]

I think that is just a glitch in the ncep page.. WSI and Weatherbell don't show that.. But i see what you are saying on the NCEP page.. Doesn't look right.. I think it shows 12 hour precip totals on the 180hr panel for some reason.

It's right at truncation. The model switches from 6 to 12 hour QPF....I'm not sure if it double counts that last 6 hour panel or something, but that's what's causing the odd frame there.

[SR Airglow]

Huh? We saw that with the last system. These things wrap up and rain to the north of the system and snow to the south of them. It's not uncommon in a big winter cut-off to cool the mid-levels sort of "all at once". So you go from a pounding heavy rain to dry slot then light snows and instability snow showers with the ULL overhead.

Yeah but this isn't really ULL snows(or at least that's not what it looked like to me), it looked like a more widespread regeneration of the precip shield. Might be reading it incorrectly, but I didn't get that feel from looking at it.

 

Edit: Could very well be an issue of increased QPF from truncation making it odd looking as PF mentioned above, that is, when smoothed over 12 hours it looks like a more widespread precip shield when it's really just an expansion of lingering stuff that's doubled due to truncation.

[powderfreak]

Yeah but this isn't really ULL snows(or at least that's not what it looked like to me), it looked like a more widespread regeneration of the precip shield. Might be reading it incorrectly, but I didn't get that feel from looking at it.

Edit: Could very well be an issue of increased QPF from truncation making it odd looking as PF mentioned above, that is, when smoothed over 12 hours it looks like a more widespread precip shield when it's really just an expansion of lingering stuff that's doubled due to truncation.

Yeah that's exactly it.

Hour 177 is a 6-hr precip total. Hour 180 is a 12-hr total so it is double counting the QPF in the overlap.

There are some light ULL snows in there, maybe up to 0.25" QPF after a snow column, but those big 0.5"+ values are just double counted from 168-180.

[Ginx snewx]

SIM satellite looks like superstorm 93