Winter 2013-14 Pattern Discussion

[buckeyefan1]

I do not see a strong signal indicating we torch for a period, at-least through ~Christmas. At the same time, the mechanisms needed to lock in the cold are not really there either. The upcoming week looks to avg slightly below on temps for many in the SE, today was much below ith a high of 37. There are still another 3 weeks left in the month, best guess is December ends up near avg (for most) with respect to temps, precip is slightly above.

I've been saying this too    

 

Actually looks pretty typical for winters in the SE, 2-3 day cold shots followed by gradual warming then a storm system ( usually rain) with strong cold front, rinse wash repeat.

Yep   

 

The problem is, as I'm sure you know, there's nothing to keep that thing from moving north. I think we stand a better chance at a 50 degree rain than a snow.

Indeed....some blocking would be nice  

 

My highest forecast high for the week is 50 tomorrow. Every other day has forecast highs in the 40s for, and after tonight, lows in the upper 20s to 30s. The averages for December 8 for RDU are 56/35. Should help to reduce the positive departures for the month so far. If true, the staying power of the SE ridge will once again have been poorly modeled.

Imagine that    

[Met1985]

With the PV in Canada we really do not need a negative AO. The EPO is doing the job right know and If we can get a big ridge in the West connecting up to AK then that will send down some very cold air along with the PV. We just need a little big of blocking from the NAO region to help support a sustained cold pattern.

[tnweathernut]

This would be good news.

https://twitter.com/bigjoebastardi/status/410074765668257792

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[FallsLake]

from what little I know you don't need a negative AO if the cold is already on our side. But not sure if there is a correlation for it and the +PNA/-NAO. Ive also read that we really don't want all the indices to be too good; that could just provide a very cold dry pattern. **but I would take my chances with it.  

[packbacker]

GFS ejects the cutoff and starts to phase with a strong northern piece of energy over west TX, which is way to soon (west) for us, thus you get this cutter. 0zEuro Op agrees.

[Southern Track]

GFS ejects the cutoff and starts to phase with a strong northern piece of energy over west TX, which is way to soon (west) for us, thus you get this cutter. 0zEuro Op agrees.

Yeah is really almost identical to the 0z Euro.

[packfan98]

I know that blocking is important for a sustained winter pattern in the SE.  However, if we can get the trough to set up a little more to the east, couldn't that keep a potential system from being a lakes cutter, app runner, etc..?  Especially if the SE ridge is held in check?

[Bsudweather]

NWS GSP is showing rain and snow for the upstate Friday night and Saturday on the point and click. Where are they getting this from? cause models are not showing anything then from what I can tell. They are also very conservative when it comes to winter weather here. So for them to be forecasting that 4 days out is odd!

[Met1985]

Storm or no storm it is going to be getting cold starting around the 15th. Pretty impressive for December. The PV shifts into SE Canada which will help keep the East in an active cold pattern. The mountains could see a few clipper like snows coming in also.

[burgertime]

For everyone talking about a -AO. IRRC we had a good bit of last winter with a -AO. What we badly need is a -NAO  and as Jerms said this will lead to good blocking. Currently the 12z GFS has a fantastic look out past 300 hours but it's past 300 hours. Given the storm that skipped us and hit the north and early little flurry we saw I think it's totally plausible for something to occur next week. Just no point in betting on it until around Thursday or Friday of this week. 

[GaWx]

12Z Goofy fwiw brings near record cold to Chicago with -20ish for O'Hare on 12/23! Well down into the teens fwiw on 12/23-24 ATL and on 12/24-5 RDU as the SE gets a pretty good hit from it though it really is glancing/quick. Overall, lots of ups and downs for the SE,. which opens up opportunities for wintry precip. depending on timing as opposed to near constant cold/dry.

 

Edit: most of TN gets below 0 F on 12/23! So even with cold bias taken into account, this airmass would be brutal for much of the US. But it is mainly for entertainment since it is 2 weeks out.

 

Edit #2: AM lows well up into the 60's much of SE on 12/22 and highs in the 70's  immediately preceding this monster cold front. Ups and downs. Huge swings.

[nchighcountrywx]

From Brad Panovich:

66.9% of the Lower 48 is covered with snow, most for this date in over a decade.

http://twitpic.com/do5fj3

[burgertime]

12Z Goofy fwiw brings near record cold to Chicago with -20ish for O'Hare on 12/23! Well down into the teens fwiw on 12/23-24 ATL and on 12/24-5 RDU as the SE gets a pretty good hit from it though it really is glancing/quick. Overall, lots of ups and downs for the SE,. which opens up opportunities for wintry precip. depending on timing as opposed to near constant cold/dry.

 

Edit: most of TN gets below 0 F on 12/23! So even with cold bias taken into account, this airmass would be brutal for much of the US. But it is mainly for entertainment since it is 2 weeks out.

 

Edit #2: AM lows well up into the 60's much of SE on 12/22 and highs in the 70's  immediately preceding this monster cold front. Ups and downs. Huge swings.

 

Which tells me we probably fall somewhere in between. That still gives us a great chance at a surprise. The million dollar question is if the GooFuS is going to stay with it, or does it keep modulating from run to run? This is an interesting winter so far and it looks to give lots of professionals fits. 

[SnowNiner]

For everyone talking about a -AO. IRRC we had a good bit of last winter with a -AO. What we badly need is a -NAO  and as Jerms said this will lead to good blocking. Currently the 12z GFS has a fantastic look out past 300 hours but it's past 300 hours. Given the storm that skipped us and hit the north and early little flurry we saw I think it's totally plausible for something to occur next week. Just no point in betting on it until around Thursday or Friday of this week. 

 

Agree, --AO last year did us no favors.  I think the big -EPO cancels out the AO in regard to getting the cold air here (in proximity).  That along with the fact that the PV seems to be on our side of the globe in Canada. 

 

The +PNA I think will eventually come around, and as was discussed, the STJ seems to keep coming so I really like the fact that we have all the ingredients for the foreseeable future.  It would just be nice if we had some Atlantic blocking to keep storms south and eliminate the need for such perfect timing. 

 

What worries me is if we lose the -EPO permanetly.....that's the big elephant in the room.  If that goes and stays positive, I think we're toast.  Get it?  No cold transport?  Toast?  Warm?  Nevermind....

[WxJordan]

The latest run of the GFS is a very interesting run, and I believe it is very close to what will occur over the next couple of weeks. I will be watching to see if the GFS continues to trend this way or if it looses it over future runs.

 

The storm coming this weekend will not bring wintry weather to the Carolinas, except a little freezing rain at the beginning before quickly changing to a cold rain. But, what this storm could be is a pattern changer. The GFS at 12 z really does not show any type of -NAO developing; however, we do have a relatively large ridge over the Pacific Ocean with cut off lows continue to eject out from the southern Pacific Ocean across the United States. A cut off low from under the ridge is what will bring rain to us over the weekend and the chance of snow in the heartland.

 

If this ridge migrates eastward towards the western United States coast, which is possible, we will really have to watch some of these cutoff lows ejecting across the southern United States and bringing a large winter storm to the southeast.

 

Additionally, this would help to push the ridge off the east coast farther eastward, which will help to cause the storm track to shift eastward and up the East Coast.

[Lookout]

12z canadian with another fantasy storm. Probably will go the way of the one it had last week in the long range.

 

[Bsudweather]

12z canadian with another fantasy storm. Probably will go the way of the one it had last week in the long range.

The way things are looking I would not be a bit surprised to see something next week! Been to many hints at something developing! We shall see.

[GaWx]

12z canadian with another fantasy storm. Probably will go the way of the one it had last week in the long range.

 

 Yeah, I hardly ever give the Canadian a consideration when it is so different from the GFS/Euro since it so inferior. Moreover, if I had a nickel for every time it showed a major N GA winter storm that didn't even come close to verifying....I mean, it is pretty bad just a few days out much less nine days lol.

[Cold Rain]

As has been said, a -AO is unnecessary for cold/winter weather, if other appropriate signals are present and the cold air is on our side of the globe. A -AO, however, does tend to correlate fairly well to a -NAO, which is a favorable signal for sustained cold and wintry threats. That reason alone is good enough to make it a preferred state. As far as I know, there is very little correlation to the PNA.

[Poimen]

As others have alluded to, if we can keep the southern stream active a good portion of the SE should eventually cash in at some point this winter. I think this is where our hope resides anyway. Time will tell.

[GaWx]

As has been said, a -AO is unnecessary for cold/winter weather, if other appropriate signals are present and the cold air is on our side of the globe. A -AO, however, does tend to correlate fairly well to a -NAO, which is a favorable signal for sustained cold and wintry threats. That reason alone is good enough to make it a preferred state. As far as I know, there is very little correlation to the PNA.

 

CR,

 However, the -AO appears to be more important for the SE and other southern locations to be dominated by cold vs., say, the Mid Atlantic, Midwest and places further north. When I read comments about the -AO not being that important, I consider the location that the person is referring to because it isn't as important up north. Also, as you said, it correlates well with -NAO.

[Cold Rain]

CR,

However, the -AO appears to be more important for the SE and other southern locations to be dominated by cold vs., say, the Mid Atlantic, Midwest and places further north. When I read comments about the -AO not being that important, I consider the location that the person is referring to because it isn't as important up north. Also, as you said, it correlates well with -NAO.

Oh, don't get me wrong; I'd rather have it negative. What I don't know is why sometimes, like last year, the -AO didn't help, and like this year, a ++AO isn't hurting too bad. This year, we have the -EPO and -WPO, so apparently, they're negating the ++AO to a large degree. That leads me to *believe* that when other specific signals are present, that it's effects are somewhat negated. Is that a wrong idea? In general, assuming no overriding factors are present, it is an important signal for the SE.

[NCSNOW]

12z canadian with another fantasy storm. Probably will go the way of the one it had last week in the long range.

 

 

Canadian has become my favorite weenie model this year. It looks like the 12z Euro from yesterday. Only way we can get either one to verify with these desired solutions in our current pattern is for the southern energy (wave) to stay opened up and not close off until past the Mississippi. That's the benchmark I always use that if you ever see a lp close off before then 99.9 % of time it's an apps runner or lakes cutter.

[DaculaWeather]

The lack of AO hasn't been so bad for us because we've had such a strong PV over on our side of the world this year. An +AO gives us a more zonal flow, which is pretty much what we've been seeing lately in the upper atmosphere. Surface temps were able to penetrate south due to the very dense cold air. Imagine if we had a -AO and -NAO at the same time that air came in, we'd be jumping up and down for joy! 

[Steven_1974]

 Yeah, I hardly ever give the Canadian a consideration when it is so different from the GFS/Euro since it so inferior. Moreover, if I had a nickel for every time it showed a major N GA winter storm that didn't even come close to verifying....I mean, it is pretty bad just a few days out much less nine days lol.

 

Since that model is so bad compared to the others, why do they even bother with it anymore?

[BullCityWx]

[POWERSTROKE]

We can get a storm without blocking but most likely most storms will be app runners until then.  Most storms always trend west most of the time.  I hope some forecasters are wrong but several are already saying rain for us as this will be another app runner late next weekend.  We need the traditional block with a gulf low then we for sure would get some good wintry weather.  It is only December 9th and already looking at our third event

[Bevo]

My highest forecast high for the week is 50 tomorrow. Every other day has forecast highs in the 40s for, and after tonight, lows in the upper 20s to 30s. The averages for December 8 for RDU are 56/35. Should help to reduce the positive departures for the month so far. If true, the staying power of the SE ridge will once again have been poorly modeled.

 

This is what I was getting at earlier.  Why would I trust these long range warmth-casts when they've not delivered since March? 

[Bsudweather]

This is close for us upstate and N GA folks for end of next weekend! But we know how it will change this far out!

[tnweathernut]

The Euro looks to be headed in a decent direction past day 7.  Certainly not seeing a torch in our future.