Winter 2014-2015 Pattern Discussion Thread I

[SnowGoose69]

Door to door winters rarely happen. 02-03 was the last one that qualifies in my area. Everything has to break absolutely perfect. I personally wouldn't make that call until after Dec and probably part of Jan is already booked and even then there's plenty of risk.

However, it's been discussed by most pros that Dec was the biggest wildcard for establishing a persistent cold winter pattern. My area finished Nov around -3-4. The rubber band always snaps back at some point. Just like a typical Jan thaw. The 800lb gorilla question right now is whether a cold winter pattern establishes in Dec or not. Many signs point favorably towards the second half getting there. Until then we all nervously await the proverbial 10+ day pattern change....ugh

I'm leaning towards it not happening at all in December or maybe only the last 5-8 days, I didn't think so a week ago but I do now

[calculus1]

https://twitter.com/WxSouth/status/539411923146915840/photo/1 robert seems too like the set up in the long range . The pna will go thou the roof we need  some blocking hopefully models will trend ?

 

Yes?  No?  I don't know?

 

That's awesome.  I was just eyeballing the 850s from the ewall page.  But like Larry said, I'm not sure where all the heatwave talk is coming from.  Maybe the CFS?

 

No. It's solely coming from snowstorm2011. 

 

On a positive note, I am really enjoying the posts from webberweather.  Keep 'em coming, good sir.

[Bob Chill]

I'm leaning towards it not happening at all in December or maybe only the last 5-8 days, I didn't think so a week ago but I do now

I'm just an armchair hobbyist of course but I agree only if the current d10-15 ens guidance has it right or it verifies even more ho hum. I'm not sold on the relentless Pac jet. I wouldn't be surprised to see heights in western north America cutting that off in tandem with the ao being favorable sooner rather than later.

The nao is troublesome but we can do ok in the east with progressive flow with well spaced amplification. Otoh- it would hardly surprise me if Dec sucks door to door in the east.

No matter which analog or tc is used at long leads, it's always similar to betting the spread in the NFL. Even the best in the business struggle to get it right 55% of the time

[FallsLake]

GFS from last night and this morning still looks bad for cold air. As other have stated hopefully it is not catching on to other changes (strat. temps, pacific storm, etc.). Ground temps are really not horrible. The air masses originate from the Pacific so it is probably slight above average for most (less the farther south you live).  

 

Ugly day 16:

http://mag.ncep.noaa.gov/Image.php?fhr=384ℑ=data%2Fgfs%2F06%2Fgfs_namer_384_850_temp_mslp_precip.gif&model=gfs&area=namer&param=850_temp_mslp_precip&group=Model+Guidance&preselected_formatted_cycle_date=20141202+06+UTC&imageSize=M&ps=model

[DaculaWeather]

The GFS is out to lunch, it can't even resolve differences within itself. 

[FallsLake]

PNA --  Looks to be strongly positive in the LR.         

AO   --  Looks to average out more negative in the LR. 

NAO -- Looks to average out positive in the LR.   

 

If we can get the PNA and AO on our side (as shown) we can deal with a positive NAO. We did for the most part last year.

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/teleconnections.shtml

[Southern Track]

PNA -- Looks to be strongly positive in the LR.

AO -- Looks to average out more negative in the LR.

NAO -- Looks to average out positive in the LR.

If we can get the PNA and AO on our side (as shown) we can deal with a positive NAO. We did for the most part last year.

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/teleconnections.shtml

Yeah, get the Pacific to cooperate and Im optimistic. I would assume if we could add the -NAO it would be less about timing of cold air and precip and lock the cold in longer to up the ante?

[Webberweather53]

That is about as classic of an El Nino/+PDO look as you'll see for December... the southern US should remain seasonably cool & potentially quiet wet w/ an active southern stream especially as we get into mid Dec, the core of the strongest +anoms should remain mainly confined to the northern tier of the US...

 

 

Years w/ >1.0 +PDO Sep & Oct Dec US temps...

 

 

Closest +PDO/MEI analogs Sep-Oct, Dec US temps

 

I urge patience from those who would like to see a cold/snowy winter this year, once again, the trend with these years remains the same as w/ various other analog packages I've shown over the last day or so, Dec starts out relatively slow & the winter turns much colder in Jan & especially February in the southeastern US...

 

Years w/ >1.0 +PDO Sep & Oct, Feb US temps

 

Closest +PDO/MEI analogs Sep-Oct, Feb US temps

 

You should also note that the winter temperature correlations to +PDO, +NINO 3.4, & +MEI are weakest to cold in the southeastern US in December, & generally grow more robust as the winter progresses. Thus, you can once again conclude that climatology favors December being the most dull/boring month of the winter in our part of the country...

 

I think it's amazing to see how close the 6-10 day pattern will be to the blend of the climatological +PDO/+ENSO look for Dec & it bodes well for us this winter, i.e. if the same pattern shows up again later in Jan or Feb, we're likely to quite a bit colder...

[Cold Rain]

With the exception of the NAO, the numerical values of those indexes are fine.  But the H5 look blows chunks, if you want sustained cold and snow opportunities (with a small exception outlined below).  This is going to be a good example of how good numbers don't translate into favorable results, if the H5 look is close to correct.

 

Take a look at the 0z Euro at 192:

 

Nice PV up in Central Canada, extending over toward Greenland (+NAO).  Nice big ocean low south of the GOA with a strong jet crashing into the Pac coast, bringing some needed rain there.  Nice PNA ridge, that tends to move east with time.  The real cold stuff is way up in Canada, wrapped up around the PV.  We do not torch in the SE.  As a matter of fact, HP continues to move across the northern tier.  There is a shortwave that has some potential to interact with that transient high pressure that could result in a brief little damming scenario/wintry weather for favored areas.

 

 

Now, here is the 6z GFS at 192 (I know it's six hours later than the Euro, but it doesn't make much difference at this lead).  It has a similar look, which I have highlighted:

 

 

This is not a terrible pattern if you like weather that's variable and close to seasonal.  But if you're looking for the icebox, there's no sign of that anywhere on these maps, even though the numerical indexes might conjure images of such things.

[LithiaWx]

10 day Euro and the 10-15 day GFS look like absolute crap if you want snow.  I think it will be another week or so before models can get in range of the possible pattern change that everyone is hoping for.  Until then enjoy the torch and eventual change to seasonal (still not cold enough for snow).

 

This will be the theme for the next week imo.  The models look like they have a great handle on things regarding how things turn out over the next 10 or so days.

[BullCityWx]

10 day Euro and the 10-15 day GFS look like absolute crap if you want snow.  I think it will be another week or so before models can get in range of the possible pattern change that everyone is hoping for.  Until then enjoy the torch and eventual change to seasonal (still not cold enough for snow).

 

This will be the theme for the next week imo.  The models look like they have a great handle on things regarding how things turn out over the next 10 or so days.

 

And models typically show pattern changes too soon, at that. We may be punting this entire month. 

[LithiaWx]

And models typically show pattern changes too soon, at that. We may be punting this entire month. 

 

Agreed, I'm starting to think any change towards a pattern that supports snowstorms in our sensible weather is looking more like late December than mid-December like some thought.  I also would not be surprised with the entire month of December ending up in the dumpster.

[DaculaWeather]

Agreed, I'm starting to think any change towards a pattern that supports snowstorms in our sensible weather is looking more like late December than mid-December like some thought.  I also would not be surprised with the entire month of December ending up in the dumpster.

 

I would be EXTREMELY surprised. 

[calculus1]

I can't remember if anyone posted the NC State Climate Office outlook for this upcoming winter.  It came out just before Thanksgiving.  Here is the link, and I've quoted their bottom-line below:

 

http://nc-climate.ncsu.edu/climateblog?id=107

 

 

 

 

The projected snowfall maps are quite interesting, as well:

 

[Bob Chill]

And models typically show pattern changes too soon, at that. We may be punting this entire month. 

 

I agree with this but maybe not so much this time because the pattern is only bad in the pac at the mid-latitudes. Things don't have to shuffle all that much to turn things in a hurry. If we had a hostile and stable pattern at the high latitudes it would be a different story. If we were facing a +AO or a big dominant +EPO right now I would be much more concerned. But we're not so when things do shift it can happen quickly.

 

The next real cold outbreak could easily be centered in the east half of the country and not some step down like we saw in Nov. Safe to say we're toast for the next 10 days and probably 15 for that matter but punting this month really can't be done for 2 weeks. We're not in a typical month long crapper pattern at all imo. 

[FallsLake]

I can't remember if anyone posted the NC State Climate Office outlook for this upcoming winter.  It came out just before Thanksgiving.  Here is the link, and I've quoted their bottom-line below:

 

http://nc-climate.ncsu.edu/climateblog?id=107

 

 

 

 

The projected snowfall maps are quite interesting, as well:

 

Something is really wrong with that snowfall average. To say Fayetteville NC averages under 2" is not right.  Even Raleigh NC under 4" is not correct. Has me right on the edge of 4-6. I think this is closer:

http://en.wikipedia.org/wiki/Climate_of_North_Carolina

[calculus1]

Something is really wrong with that snowfall average. To say Fayetteville NC averages under 2" is not right.  Even Raleigh NC under 4" is not correct. Has me right on the edge of 4-6. I think this is closer:

http://en.wikipedia.org/wiki/Climate_of_North_Carolina

 

Well, the Climate Office is only using the 1981-2010 totals to get their averages.  Perhaps Wikipedia's references use data that goes back further in time.

[packbacker]

Something is really wrong with that snowfall average. To say Fayetteville NC averages under 2" is not right.  Even Raleigh NC under 4" is not correct. Has me right on the edge of 4-6. I think this is closer:

http://en.wikipedia.org/wiki/Climate_of_North_Carolina

 

RDU's 30 year snowfall average was 7" back in 2005, but has since dropped to 5.5" since our seasonal snowfall since then has been horrific.  The 30 year average from 1981-2010 is roughly 6".

 

Also, that map has GSO as 4-6", they are probably closer to 9".  

 

Looking at the wikipedia, those numbers were pulled from 2008, so 7" is close.  If you check there source now it states 6", which is close enough.   But it's not 2-4", we haven't been 2-4" range ever, although with as bad as things have been the past 20 years we are on our way.

[FallsLake]

Well, the Climate Office is only using the 1981-2010 totals to get their averages.  Perhaps Wikipedia's references use data that goes back further in time.

Here's another that puts downtown Raleigh at 6":

http://www.erh.noaa.gov/rah/climate/data/RDU_monthlysnowfall.pdf

[GaWx]

Look at how warm Dec. 1939 was for practically the entire country (over 10 degrees warmer than normal upper Midwest to N Plains) (but with the east/SE having a much smaller warm anomaly) and then look at how frigid was Jan. of 1940 for much of the country (10 or more below normal much of E and C US!). For a multitude of reasons, 1939-40 has been one of my top analogs, if not my top analog:

 

Dec. of 1939

 

Jan. of 1940

[FallsLake]

What's worse a SE ridge or a tropical storm:

 

http://mag.ncep.noaa.gov/ImageFourPanel.php?image=data%2Fgfs%2F12%2Fgfs_namer_312_200_wnd_ht%7C500_vort_ht%7C1000_500_thick%7C850_temp_ht_s.gif&model=gfs&area=namer&cycle=12&param=200_wnd_ht%7C500_vort_ht%7C1000_500_thick%7C850_temp_ht&fhr=312&group=Model+Guidance&preselected_formatted_cycle_date=20141202+12+UTC&ps=model&use_mins=no&scrollx=0&scrolly=0

[NCSNOW]

Nice post Larry. Didn't know that about 39. Sit tight folks, bet we have atleast 10 plus dedicated threads to winter weather events by the end of March.

Currently I'm sitting here at 39 degrees in wind wept drizzle. Only 30 plus degrees colder than this time yesterday. Tamlands favorite kind of weather.

[Brick Tamland]

 

This is not a terrible pattern if you like weather that's variable and close to seasonal.  But if you're looking for the icebox, there's no sign of that anywhere on these maps, even though the numerical indexes might conjure images of such things.

 

We don't need to be in the icebox to have good snowstorms. In fact, we usually do better with the temps around 30 to 28 than when we are in the deep freeze. The deep freeze usually comes with dry weather here.

 

 

Agreed, I'm starting to think any change towards a pattern that supports snowstorms in our sensible weather is looking more like late December than mid-December like some thought.  I also would not be surprised with the entire month of December ending up in the dumpster.

 

 

I can't remember if anyone posted the NC State Climate Office outlook for this upcoming winter.  It came out just before Thanksgiving.  Here is the link, and I've quoted their bottom-line below:

 

http://nc-climate.ncsu.edu/climateblog?id=107

 

 

 

 

The met that posted that with the NC State Climate Office, other mets, and folks like WxSouth have said the end of the month is when we should start to get interesting. December is just setting the stage. We just have to be patient. December always goes by fast, so the fun will be here before you know it.

[buckeyefan1]

With the exception of the NAO, the numerical values of those indexes are fine.  But the H5 look blows chunks, if you want sustained cold and snow opportunities (with a small exception outlined below).  This is going to be a good example of how good numbers don't translate into favorable results, if the H5 look is close to correct.

 

Take a look at the 0z Euro at 192:

 

Nice PV up in Central Canada, extending over toward Greenland (+NAO).  Nice big ocean low south of the GOA with a strong jet crashing into the Pac coast, bringing some needed rain there.  Nice PNA ridge, that tends to move east with time.  The real cold stuff is way up in Canada, wrapped up around the PV.  We do not torch in the SE.  As a matter of fact, HP continues to move across the northern tier.  There is a shortwave that has some potential to interact with that transient high pressure that could result in a brief little damming scenario/wintry weather for favored areas.

 

euro192.gif

 

Now, here is the 6z GFS at 192 (I know it's six hours later than the Euro, but it doesn't make much difference at this lead).  It has a similar look, which I have highlighted:

 

f192.gif

 

This is not a terrible pattern if you like weather that's variable and close to seasonal.  But if you're looking for the icebox, there's no sign of that anywhere on these maps, even though the numerical indexes might conjure images of such things.

Everyone seems to forget we live in the south and constant cold only happens once or twice in a lifetime around here. I'll take my chances with "seasonal/normal" every winter if given the opportunity.    

 

I agree with this but maybe not so much this time because the pattern is only bad in the pac at the mid-latitudes. Things don't have to shuffle all that much to turn things in a hurry. If we had a hostile and stable pattern at the high latitudes it would be a different story. If we were facing a +AO or a big dominant +EPO right now I would be much more concerned. But we're not so when things do shift it can happen quickly.

 

The next real cold outbreak could easily be centered in the east half of the country and not some step down like we saw in Nov. Safe to say we're toast for the next 10 days and probably 15 for that matter but punting this month really can't be done for 2 weeks. We're not in a typical month long crapper pattern at all imo. 

Indeed     

[superjames1992]

Something is really wrong with that snowfall average. To say Fayetteville NC averages under 2" is not right.  Even Raleigh NC under 4" is not correct. Has me right on the edge of 4-6. I think this is closer:

http://en.wikipedia.org/wiki/Climate_of_North_Carolina

 

Yeah, I'm pretty sure that map is off.  GSO's average is around 7.6-9", from everything else I've ever seen.  The median is probably in the 4-6" range, though.

 

2-4" for Raleigh seems ridiculous.  I'd bet they've averaged that even during the awful winters over the last decade.  There's been enough big daddy storms to make the average somewhat respectable since 2000, even with multiple terrible winters.

[calculus1]

Something is really wrong with that snowfall average. To say Fayetteville NC averages under 2" is not right.  Even Raleigh NC under 4" is not correct. Has me right on the edge of 4-6. I think this is closer:

http://en.wikipedia.org/wiki/Climate_of_North_Carolina

 

RDU's 30 year snowfall average was 7" back in 2005, but has since dropped to 5.5" since our seasonal snowfall since then has been horrific.  The 30 year average from 1981-2010 is roughly 6".

 

Also, that map has GSO as 4-6", they are probably closer to 9".  

 

Looking at the wikipedia, those numbers were pulled from 2008, so 7" is close.  If you check there source now it states 6", which is close enough.   But it's not 2-4", we haven't been 2-4" range ever, although with as bad as things have been the past 20 years we are on our way.

 

Yeah, I'm pretty sure that map is off.  GSO's average is around 7.6-9", from everything else I've ever seen.  The median is probably in the 4-6" range, though.

 

2-4" for Raleigh seems ridiculous.  I'd bet they've averaged that even during the awful winters over the last decade.  There's been enough big daddy storms to make the average somewhat respectable since 2000, even with multiple terrible winters.

 

I will readily admit that I am not an expert on RDU weather.  I think the numbers on the map look pretty good for HKY.  I can't imagine that the state Climate Office would put out something that is so horribly wrong without fact-checking it somehow.  So, maybe we're missing something in how they arrived at their numbers for RDU.  Perhaps they're using the median average rather than the mean average.  Anyway, what we can all take away from it, while we debate the numbers, is that their analogs point to greater than normal expected snowfall for pretty much the entire state this winter season.  Now, we must simply wait to see whether they are correct in this assertion as the rest of the winter (including the month of December) unfolds.

[Brick Tamland]

I always thought 6 inches for RDU was the average.

[LithiaWx]

12Z Euro is a dumpster fire :

 

 

 

There is so much wrong with this map, it's hard to know where to begin.

 

1.  The west coast has a bad look for us

2. The upper Midwest is a flamethrower torch

3. The SE looks seasonal but that said NOTHING wintery can develop in the SE with the way the rest of the map looks.

 

 

 

[LithiaWx]

And more facepalm :

 

 

That's an UGLY map, lower heights off the west coast is a killer.

[GaWx]

Due to the continued negativity, it is time for the next installment of favorable analog therapy:

 

Chicago Dec 1939/Jan. 1940 daily departures from normal: a tale of two mind bogglingly different months:

 

Day....Dec.....Jan

 

1.......+10......-11

2.......+5......-15

3........0........-12

4.......+1......-14

5.......+6......-14

6.......+9......-9

7.......+15....-2

8.......+10....+2

9.......+17.....0

10.....+16....+3

11.....+8......+10

12....+12.....+6

13.....+3......+8

14......0......+9

15.....+10....-7

16.....+15....-11

17.....+18....-17

18.....+20....-31

19.....+15....-25

20.....+3......-15

21......0......-12

22.....+1......-8

23.....+4......-5

24.....+4.....-14

25.....+6.....-19

26.....+4.....-18

27.....+2.....-15

28.....0........-9

29.....0.......+1

30....-10....+4

31....-15....+6