Winter 2013-14 Pattern Discussion II

[SnowNiner]

Jan 2000 had blocking, so did Feb 2004 big event, so did Jan 2002 big event.  We can get snow with the +NAO but usually just small ones, 1-2".  It's going to be hard to get blocking with the PV sitting over Hudson Bay, that's been a staple of this winter and doesn't look like that is changing, so we are going to have to hope for 1" type events this winter.  Odds of a 6" event this winter is virtually nil.

 

 

 

 

 

 

Yeah, I'm done with hoping for blocking.  I'm hoping for an 88 over running event redux, lots of moisture and just cold.  If we can get a split flow as advertised with the PV nice and south I think that's still on the table.  Focusing on the next two weeks; pattern looks good. 

[frazdaddy]

 

If I remember right, February was an obscene torch, though some of the massive snow piles still lasted a very long time.

Yepp I remember how bizzare the steam coming off the piles looked.

[Southern Track]

Yeah, I'm done with hoping for blocking. I'm hoping for an 88 over running event redux, lots of moisture and just cold. If we can get a split flow as advertised with the PV nice and south I think that's still on the table. Focusing on the next two weeks; pattern looks good.

I was about to post the same storm. No blocking during that bad boy.

[Jon]

This is a little concerning. Looking at the CPC site, it has the PNA very positive but does dive negative in the LR, the NAO goes and stays positve from it's current slight negative value, and the AO looks to go positive from it's current negative vaule. This look would scream warm up around day 16 or so(1st week of February. This upcoming two weeks may be our best chance for wintery precip this winter. It would be very nice to get one of these fantasy storms to verify.

Not sure if I buy it. One would say "yeah we're likely to get another thaw" especially if the PV drops down like it's progged to, again, late month.

 

The OP Euro at 240 has a deep ridge between the classic +PNA location and the aleutians, with what I think is the next influx of cold headed south as the trough exits stage right.

 

As you can see on the control, this leads to a blocky look and another cold/stormy pattern following. That look would be juicy.

In my opinion, GEFS (CPC site teleconnections) don't make sense here.

 

The GEFS mean HAS the same exact look at 252hrs with the ridge between the aleutian islands & classic +PNA. Instead of continuing with the pattern and cold in the east, the ridge moves over the aleutians and the trough is hung from eastern canada allllll the way to the west, building a trough in the west with a ridge in the east. With the location of the PV does this make sense? No.

This is responsible for the CPC teleconnections looking the way they do and I don't buy it. Once the GEFS catches up so should the CPC site.

[FallsLake]

Jon, What's amazed me is the indices have been crap all winter and we've still had notiable cold spells. Even if the depiction from the CPC site verified we couldn't rule out cold air. I would say the only thing it has done was hurt our snow chances. Hopefully what you show above will occur and we continue this nice pattern into February.   

[SnowNiner]

Jon, What's amazed me is the indices have been crap all winter and we've still had notiable cold spells. Even if the depiction from the CPC site verified we couldn't rule out cold air. I would say the only thing it has done was hurt our snow chances. Hopefully what you show above will occur and we continue this nice pattern into February.   

 

We've had the cold air with bad indicies because of the big -EPO.  That's led to nothing for the south east other than dry cold.  I think a big +PNA is absolutely imperative in order to have any hope to get snow in this pattern.  Have to have a sharp trough in the east get storms to our south. 

 

Hopefully the big -EPO ridge keeps our +PNA into February. 

[FallsLake]

We've had the cold air with bad indicies because of the big -EPO.  That's led to nothing for the south east other than dry cold.  I think a big +PNA is absolutely imperative in order to have any hope to get snow in this pattern.  Have to have a sharp trough in the east get storms to our south. 

 

Hopefully the big -EPO ridge keeps our +PNA into February. 

12z GFS LR still looks great. You mentioned the 88 storm (more of over-running) and it has that look for many of the potential(fantasy) events.

[BullCityWx]

daddy like.

 

[BullCityWx]

daddy REALLY like

 

[packfan98]

daddy REALLY like

 

I think the whole SE family likes!  Matches up timewise with some of the Euro and GFS runs for a storm around this time period if I remember correctly.

[mackerel_sky]

Looks great and only 11 days out! Better than 15

[BullCityWx]

I think the whole SE family likes!  Matches up timewise with some of the Euro and GFS runs for a storm around this time period if I remember correctly.

 

and that fits to a T the kind of storm in this pattern that could be a significant storm for us. 

[Cold Rain]

I think the whole SE family likes!  Matches up timewise with some of the Euro and GFS runs for a storm around this time period if I remember correctly.

[BullCityWx]

 

I think the whole SE family likes!  Matches up timewise with some of the Euro and GFS runs for a storm around this time period if I remember correctly.

 

 

[DaculaWeather]

Not sure if I buy it. One would say "yeah we're likely to get another thaw" especially if the PV drops down like it's progged to, again, late month.

 

The OP Euro at 240 has a deep ridge between the classic +PNA location and the aleutians, with what I think is the next influx of cold headed south as the trough exits stage right.

 

As you can see on the control, this leads to a blocky look and another cold/stormy pattern following. That look would be juicy.

 

In my opinion, GEFS (CPC site teleconnections) don't make sense here.

 

The GEFS mean HAS the same exact look at 252hrs with the ridge between the aleutian islands & classic +PNA. Instead of continuing with the pattern and cold in the east, the ridge moves over the aleutians and the trough is hung from eastern canada allllll the way to the west, building a trough in the west with a ridge in the east. With the location of the PV does this make sense? No.

 

This is responsible for the CPC teleconnections looking the way they do and I don't buy it. Once the GEFS catches up so should the CPC site.

Agreed. I would think that with such massive Aleutian height anomalies, that you'd see similar corresponding height falls out ahead of it. 

[Cold Rain]

^^ That looks good....Just looking at the snapshot of the image at 240, the surface map shows a weak Low in NE NC and no HP to the north, except for the one way out in the north Atlantic.  That's not a depiction that screams snow/ice to me.  But, that's just a snapshot.  Hard to tell about thermal profiles or any insitu CADding that might be in place from that map, so thanks for posting the follow-up!

 

Edit:  That would be one heck of a sleet storm.

[packfan98]

^^ That looks good....Just looking at the snapshot of the image at 240, the surface map shows a weak Low in NE NC and no HP to the north, except for the one way out in the north Atlantic.  That's not a depiction that screams snow/ice to me.  But, that's just a snapshot.  Hard to tell about thermal profiles or any insitu CADding that might be in place from that map, so thanks for posting the follow-up!

Too far away for specifics anyway.  Just gives us an idea of when there is a chance for a bigger storm than these moisture starved clippers.

[BullCityWx]

There's actually a little damming ahead of the system at 216

[Cold Rain]

Too far away for specifics anyway.  Just gives us an idea of when there is a chance for a bigger storm than these moisture starved clippers.

 

Yep, that's the biggest take-away.  Don't know why we even spend time talking about specific details of 10 day storms anyway.  Got nothing better to do, I guess.  At least we're seeing a few fantasy storms now to disect!

[Cold Rain]

There's actually a little damming ahead of the system at 216

 

Either way, I think this period is ripe for a storm.  The 12z GFS doesn't show one exactly at that time, but this is a good period to watch for something to develop.  I like our chances.

[jburns]

There's actually a little damming ahead of the system at 216

 

That would be Brick.  Oh, wait, I thought that was an "n".  You mean the other type of damming.

[GaWx]

This could rival or even surpass the 1973 ice storm, thoughts??

 

 It is always hard to compare to one of the worst, if not the worst, ice storm in Atlanta history as that one produced around 3" of ZR!! So, literally as modeled, it wouldn't be nearly as much liquid equivalent. Regardless, 1" of ZR would be major and big trouble. Also, the temp.'s look solidly below freezing as opposed to borderline. Then again, 1973 was borderline (mainly ~31-2) and was one of the worst ever! Anyway, details that far out are not important, of course. However, this shows the potential, especially based on neutral negative ENSO climo. Not surprisingly, nothing even close to this was on the next run (12Z GFS).

[max100]

 It is always hard to compare to one of the worst, if not the worst, ice storm in Atlanta history as that one produced around 3" of ZR!! So, literally as modeled, it wouldn't be nearly as much liquid equivalent. Regardless, 1" of ZR would be major and big trouble. Also, the temp.'s look solidly below freezing as opposed to borderline. Then again, 1973 was borderline (mainly ~31-2) and was one of the worst ever! Anyway, details that far out are not important, of course. However, this shows the potential, especially based on neutral negative ENSO climo. Not surprisingly, nothing even close to this was on the next run (12Z GFS).

Thanks for the explanation,  The one in 73 was amazing and we have never had anything remotely close to that one.

[Cold Rain]

Brick, the Euro looks predominately cold and dry through 240...mabye a quick clipper-type system or two, but it's hard to say.

[max100]

Tweet from JB.

 

"Think once again, people will be shocked at what is coming, this time longer duration for entire nation.12-20 day onslaught"

Some of the models have Atlanta near or below 0 by month end.

 

Another Tweet

 

"I believe when totaled up, the economic impact of cold from Jan 20-Feb 5 on the US will be the winter equal of a major hurricane hit on US"

 

This is pretty alarming, IMO

[jburns]

Tweet from JB.

 

"Think once again, people will be shocked at what is coming, this time longer duration for entire nation.12-20 day onslaught"

Some of the models have Atlanta near or below 0 by month end.

 

Another Tweet

 

"I believe when totaled up, the economic impact of cold from Jan 20-Feb 5 on the US will be the winter equal of a major hurricane hit on US"

 

This is pretty alarming, IMO

That's a pretty safe bet for a major arctic outbreak.  Think of the difference in area coverage between that and a hurricane.

[Lookout]

 It is always hard to compare to one of the worst, if not the worst, ice storm in Atlanta history as that one produced around 3" of ZR!! So, literally as modeled, it wouldn't be nearly as much liquid equivalent. Regardless, 1" of ZR would be major and big trouble. Also, the temp.'s look solidly below freezing as opposed to borderline. Then again, 1973 was borderline (mainly ~31-2) and was one of the worst ever! Anyway, details that far out are not important, of course. However, this shows the potential, especially based on neutral negative ENSO climo. Not surprisingly, nothing even close to this was on the next run (12Z GFS).

I think that is the storm that my parents said caused them to lose power for over 2 weeks. It's hard to even  imagine that much freezing rain and how much damage it would cause.

 

at any rate, although the models have been in half way decent agreement on the cold, they sure are flipping around from run to run on individual systems. It's virtually impossible to believe anything the models are showing up in the medium range. One would think though with so much cold air around, something significant has to meet up with it sometimes. But of course things always seem to find a way to screw us lol. 

 

But It would be so disappointing to have so much cold air here or nearby,  especially in january, and come away with nothing.

[oconeexman]

I think that is the storm that my parents said caused them to lose power for over 2 weeks. It's hard to even imagine that much freezing rain and how much damage it would cause.

at any rate, although the models have been in half way decent agreement on the cold, they sure are flipping around from run to run on individual systems. It's virtually impossible to believe anything the models are showing up in the medium range. One would think though with so much cold air around, something significant has to meet up with it sometimes. But of course things always seem to find a way to screw us lol.

But It would be so disappointing to have so much cold air here or nearby, especially in january, and come away with nothing.

Just a novice question but the problems modeling these systems is it due to the continued fast/progressive flow?

From what I've read from Robert and others the difference for this outbreak is it won't get pushed out as easy once we get a system coming our way.

[Cold Rain]

Just a novice question but the problems modeling these systems is it due to the continued fast/progressive flow?

From what I've read from Robert and others the difference for this outbreak is it won't get pushed out as easy once we get a system coming our way.

 

Partly.  There is a lot of energy in the flow.  With a big, tall PNA ridge, and no southern stream, you have to rely on energy diving out of the north to generate any lift and precip.  Models aren't very good nailing down the specifics of these waves days in advance.  Generally, they can tell you a shortwave is coming, in the near and medium terms.  But the subtleties in strength, direction, speed, whether or not they have a kicker, etc. make all the difference as to whether or not you get precipitation and also the type of precipitation.

 

This pattern, if correct, is different from the last time in that the PNA ridge stays in place for a longer period of time, rather than marching across the country or getting beat down by a fast Pacific jet, and is of sufficient amplitude (and linking with the forming -EPO) to keep a trough in the east in spite of the poor Atlantic.  The placement and amplitude of this ridge along with the harder-to-predict individual shortwaves rounding the top and diving SE will drive precipitation chances here.  This type of pattern makes it notoriously hard to define storm threats at long leads.

[oconeexman]

Partly. There is a lot of energy in the flow. With a big, tall PNA ridge, and no southern stream, you have to rely on energy diving out of the north to generate any lift and precip. Models aren't very good nailing down the specifics of these waves days in advance. Generally, they can tell you a shortwave is coming, in the near and medium terms. But the subtleties in strength, direction, speed, whether or not they have a kicker, etc. make all the difference as to whether or not you get precipitation and also the type of precipitation.

This pattern, if correct, is different from the last time in that the PNA ridge stays in place for a longer period of time, rather than marching across the country or getting beat down by a fast Pacific jet, and is of sufficient amplitude (and linking with the forming -EPO) to keep a trough in the east in spite of the poor Atlantic. The placement and amplitude of this ridge along with the harder-to-predict individual shortwaves rounding the top and diving SE will drive precipitation chances here. This type of pattern makes it notoriously hard to define storm threats at long leads.

Thank you for the explanation!