Winter 2013-14 Pattern Discussion

[Cold Rain]

@Shawn: Yep, that's right. We should get a little help in that area. No blocking in site anywhere.

@Dac: Yep, that's right too. Another false start. After failing to establish a SE ridge after many attempts, now that it's finally here, we can't succeed in getting rid of it.

[DaculaWeather]

Hopefully it's not a trend, although I don't see how we're going to get any meaningful cold air until the PV gets displaced by high pressure. With no -NAO, everything cruises to our north. 

[packbacker]

Starting to see heights that would at-least be semi-conducive for SE winter wx on the GFS, big question is does the PV (lowest heights in the NH) lock in to Canada or does it split and a piece retrograde to the Norwegian / Greenland Sea.  12z EC ens mean would argue the vortex splits with the stronger lobe cutting near iceland, Op agrees, GFS too.  Unsure at this point whether this is just perturbation in the models, as the pattern post Christmas could be volatile,  eastern US setting up for a cold-carved out period possibly beyond day 10.

 

Yep, that's what both the 11-15 days GFS/Euro ensembles are showing, not good, if that were to occur we would be looking at seasonal temps, no blocking and the cold not near the US.  This takes us to the end of Dec, which means it could be a while before we see a favorable pattern.

[Cold Rain]

Hopefully it's not a trend, although I don't see how we're going to get any meaningful cold air until the PV gets displaced by high pressure. With no -NAO, everything cruises to our north.

This feels like the base pattern for a while, with a few variations from time to time. With the +AO/+NAO/-WPO/-EPO all apparently stable features for the foreseeable future, I can't see any reason to expect anything much different than what we're seeing now: in and out cold shots, warm ups, systems, cool downs, with a recurring SE ridge as a stable feature.

There is no significant sustained window for wintry weather as long as that pattern continues to repeat.

But the good thing is, there is a lot of cold air nearby and plenty of high pressure being generated. Because of variations in the pattern that will occur from time to time, we will have some shots at winter weather, across parts of the SE at least. TN, the NC mountains, and the CAD regions are the favored areas.

[DaculaWeather]

I was looking at the WPO this morning and that latest forecast was taking it upward.

http://www.daculaweather.com/4_teleconnections_graphs.php

[tarheelwx]

If all the main indices flipped, would we be better off? The current pattern has done us almost no good. While we say we need some changes to get -nao, etc, that may also mean losing the -wpo. Would we be happy with that trade off?

TW

[nchighcountrywx]

As many times in early December, the primary winter pattern set in 2 weeks ago with the pattern change right after Thanksgiving this year taking out chances for significant snow in North Carolina for at least 40% of winter.

Can we salvage the second half? It remains to be seen but I would give it less than a 50% chance with the major SE ridge in play.

The mountains are not even getting NW flow upslope snow with the glancing intrusions of cold. A freezing rain advisory is about all that van be mustered up.

[packbacker]

As many times in early December, the primary winter pattern set in 2 weeks ago with the pattern change right after Thanksgiving this year taking out chances for significant snow in North Carolina for at least 40% of winter.

Can we salvage the second half? It remains to be seen but I would give it less than a 50% chance with the major SE ridge in play.

The mountains are not even getting NW flow upslope snow with the glancing intrusions of cold. A freezing rain advisory is about all that van be mustered up.

 

Agreed, this EPO/WPO driven weather pattern is great at getting us cold rains, you mountain folks light events, and it's great at getting the NE events but it sucks for everyone south of Richmond.  I know we can get winter events without blocking but it's very difficult, it's very difficult to get winter events down here with great blocking.  So a re-shuffle of the pattern around Xmas is a good thing, it's just going to be a few weeks and we are going to be relegated to looking at 11-15 ensemble means for hope.  In a few weeks I am sure we will start hearing the usual, "February is our best month for snow anyways".  Can we really get skunked 3 years in a row, happened before, we will see, long ways to go.  Good news is the pacific has been favorable, if we can get that to continue and add in some blocking we will have a good chance.

[Poimen]

Day 7 GFS is piquing my interest, a bit:

 

[NCCatawba]

Day 7 GFS is piquing my interest, a bit:

 

To be fair, nearly every system this December with any moisture strapped on it has piqued someone's interest to create a thread for it. They haven't been too far off tho, just a few degrees above freezing with cold rain for most. If this theme continues its just a matter of time we score getting closer to climo for a major winter storm.

 

I see the long range GFS is showing some >1060 highs. I bet we start seeing some fantasy storms post hr300 eventually.

 

 

For now, it looks like torches immediately followed by cad event setups that could or could not bring freezing rain. Similar to what we have experienced....take or minus your degree of torchiness in your local area.

[Poimen]

Well, there are some big changes at hr 180 versus 192 from the 0Z run. Hard to tell at this range, but there appears to be an ice signal for the CAD regions, we'll see.

[CAD_Wedge_NC]

Day 7 GFS is piquing my interest, a bit:

 

 

 

Yeah, it's showing very cold confluence in SE Canada. This is a new look and vastly different from the 06z run. Wait and see if this is an outlier or a trend.

[Cold Rain]

^ Yep...-30 850s in SE Canada.  And good grief it's cold in the LR.  What a pattern.  It sends a 1056 HP into Montana!

[IWC]

My 2 cents; The thing I've not heard anyone mention is northern snow cover. With all the storm coming acrossed the nation covering the north with snow it seems to me that we are just sitting and waiting for the flood gates to open and the cold to come in and stay for a period of time. Then we will not have storms chasing cold air out. Just my 2 cents.

[tarheelwx]

Wouldn't it be funny if we had ice next weekend rather than torch?  12z gfs is kind of looking that way for NC/VA cad.

TW

[Southern Track]

My 2 cents; The thing I've not heard anyone mention is northern snow cover. With all the storm coming acrossed the nation covering the north with snow it seems to me that we are just sitting and waiting for the flood gates to open and the cold to come in and stay for a period of time. Then we will not have storms chasing cold air out. Just my 2 cents.

I think it's more that the cold air doesn't moderate as much as it comes south over a snow pack.

[griteater]

Little faith in the pre-Christmas storm being cold enough with the strong warm air advection...looks like another tease to me.  Thereafter, maybe we get a little colder if the ridge along the west coast works out

[Cold Rain]

Little faith in the pre-Christmas storm being cold enough with the strong warm air advection...looks like another tease to me. Thereafter, maybe we get a little colder if the ridge along the west coast works out

Oh ye of little faith. You mean a 1028 high doesn't do it for you?

[Poimen]

Little faith in the pre-Christmas storm being cold enough with the strong warm air advection...looks like another tease to me.  Thereafter, maybe we get a little colder if the ridge along the west coast works out

 

I agree , but I just add this to the discussion. A CAD event next weekend would actually fit well with what we have seen in recent weeks (including this weekend). Of course, whether it will be cold enough for ice is something we will have to watch as we get closer.

[dsaur]

Well, I had a low in the mid twenties, and the high the next day never got out of the 40's, and 24 hours later I've got pouring rain. Seems to me fast forward to Jan. when climo says yes, and put those two factors together with a little hitch in the colds giddy up, and you've got sleet and snow, or worst case zr.  Keep putting cold and rain in the same time frame and sooner or later you'll luck into some timing, lol.  It's the south where timing is king and it always takes two to tango   It's winter, and it will always get cold enough for a few days, it's the moisture you have to worry about.  As long as it keeps raining in winter timing has a chance.  Tony

[Batman]

As many times in early December, the primary winter pattern set in 2 weeks ago with the pattern change right after Thanksgiving this year taking out chances for significant snow in North Carolina for at least 40% of winter.

Can we salvage the second half? It remains to be seen but I would give it less than a 50% chance with the major SE ridge in play.

The mountains are not even getting NW flow upslope snow with the glancing intrusions of cold. A freezing rain advisory is about all that van be mustered up.

Trying not to be overly critical here, but this post has me scratching my head. How do we know that the primary pattern for the entire winter set in two weeks ago. What pattern was that? Was it the 3 days that we were 15-20 degrees above normal. Is that the primary pattern for the winter? The way I see it, that wasn't even the primary pattern for December. The first couple days of December were at or slightly below average. The last week has been below average. We have had good rains this month thus far. That to me is not the sign of an overpowering SE ridge. I have seen Decembers with an overpowering SE ridge and this is not it. Maybe folks are getting upset because it is colder and snowier to our north and west. Many winters evolve by stepping down. Many winters in the southeast never evolve into anything. I would take where are now (good moisture flow and cold air close by) compared to many Decembers in my 22 years in Georgia.

[BullCityWx]

The weekend before Christmas looks like it'll feel more like the weekend before Easter.

[Cold Rain]

Euro and GFS are in fairly good agreement at 240.

Crappy 1:

And Crappy 2:

[BIG FROSTY]

Euro and GFS are in fairly good agreement at 240.

Crappy 1:

f240.gif

And Crappy 2:

gfs240.gif

Heck of a winter pattern, just hope we can hold on to it till March!!!

[BIG FROSTY]

WXSOUTH ‏@WxSouth 1m

Watch for big closed ridge in west Canada later. If so, snow and ice comes to interior Southeast late month. #mswx #alwx #gawx #scwx #ncwx

 

 

 

WXSOUTH ‏@WxSouth 1m

Theory of weekend storms in South. It's working. Next weekend, another big one #rain #ice Could be ice #txwx #okwx #arwx #kywx #vawx

[CAD_Wedge_NC]

The weekend before Christmas looks like it'll feel more like the weekend before Easter.

 

Easter can fall in March and we have even had snow on Easter. How should we take your post?

[BullCityWx]

Easter can fall in March and we have even had snow on Easter. How should we take your post?

Highs in the 70's, lows in the 60's. Humid.

Actually sounds a little more like Memorial Day.

[SnowNiner]

Robert seems to be pumping up the end of the month pretty good. From the models, don't know if he's crazy or a genius...I think he expects the western ridge to amplify and give us a pos pna. That would be great but I don't see it showing up on the models yet.

[Wow]

Until I see a sustained -NAO I'm going to be guarded about any winter threats showing up.  It's good to have plentiful cold air on our side of the globe but we need Atlantic blocking to displace the vortex far enough south.

 

If and when it arrives, then I'll be full throttle.

[Shawn]

Until I see a sustained -NAO I'm going to be guarded about any winter threats showing up.  It's good to have plentiful cold air on our side of the globe but we need Atlantic blocking to displace the vortex far enough south.

+100

 

I don't really like the look of anything, even around Christmas.  No matter who tries to make me think differently with their theories.. nothing really super stands out without favorable teles.

 

JB did say earlier that he thought maybe the Euro was holding too much energy back in the SW further from now.. and the energy ends up phasing to create a bigger Wintry deal, but I don't know where he meant for.. or where he thought the phase was.. I think it was more of a general statement.