Winter 2014-2015 Pattern Discussion Thread I

[Jon]

There's not going to be a cutter for the storm next weekend on the 12z run of the GFS.  1029 High anchored in Wisconsin.

There's a storm thread for that now if you didn't know, just don't want your post lost.

[Jon]

12z GFS was very close for the Christmas storm, 1012mb off of SC then 1004 mb off of NC...by then the 850mb line is into NC but the moisture is off the coast.

[GaWx]

12z GFS was very close for the Christmas storm, 1012mb off of SC then 1004 mb off of NC...by then the 850mb line is into NC but the moisture is off the coast.

 

Regardless, the 12Z GFS says that anyone doubting the pattern change after seeing it and other models must be on crack. It gives the SE a cooldown to near or a little below normal for 12/21-5 followed by a strong cold blast 12/26-28. The Cohen and 1939-40 analogs are liking this kind of thing fwiw.

[Cold Rain]

Jon, I don't really know how the value is calculated (-NAO). I just like to look at the H5 maps and see if we see ridging or blocking (that's not transient) in the Greenland/eastern Canada area. Looking at the 384 0z GFS, I drew a ridge over top of the big 50/50 type low. I think that qualifies as a -NAO and if it's not transient, would be helpful to us. Given that it's 15 days away, I'm not ready to buy into it, but that 384 hr map is not a bad look: -NAO, -AO, +PNA. I'd take it!

[MichaelJ]

DT gives an excellent explanation over on the mid-atlantic forum on when and why the pattern morphs into a great one for us right around Christmas http://www.americanwx.com/bb/index.php/topic/44997-december-medlong-range-disco/page-23

[FallsLake]

If your looking for a white(or icy) Christmas, I think the GFS looks good for this far off. Verbatim it does not cut it this run (don't like that GL low) but it is setup to be able to trend in our favor. That's all we can hope for at this range.  

[Jon]

DT gives an excellent explanation over on the mid-atlantic forum on when and why the pattern morphs into a great one for us right around Christmas http://www.americanwx.com/bb/index.php/topic/44997-december-medlong-range-disco/page-23

Good disco about why it's hard to see the -NAO developing near Christmas!

[tnweathernut]

Good disco about why it's hard to see the -NAO developing near Christmas!

I didn't get that at all.  I think he was saying the NAO cooperates as we head into January.  The other items (i.e. the AO, EPO, PNA) really get their act together around the time of Christmas.  JMO of what I read though.

[Jon]

I didn't get that at all.  I think he was saying the NAO cooperates as we head into January.  The other items (i.e. the AO, EPO, PNA) really get their act together around the time of Christmas.  JMO of what I read though.

Ok so DT says the -NAO will develop for January in his last line if I recall. For the past few days I've seen the NAO go neutral by the 25th and stay negative for the rest of the month. That's what I meant by develop by Christmas. I probably should have said this shows it can develop. It can, indeed, go negative by the Christmas. DT is just saying the -NAO will develop by January which I agree. We're talking a week here. If the NAO goes neutral on the 25th and negative by Dec 26 that's a -NAO in the current state. He's also using weekly CFSv2 means (week 3 and 4) for his analysis near the end of when the NAO will show up. I think he posted the new 00z Euro EPS at 324 showing how it's currently at +NAO at that time frame, he's correct given he buys that exact model output and run. But it's splitting hairs as the NAO was neutral by the 25th and going negative on the 12z EPS mean yesterday...so no one really knows when this will occur, saying it will develop in January is like playing the lottery and the odds are 1:1, you're going to win.

[burgertime]

Didn't see it mentioned but the 12z GEFS looks really good in the LR. Just more added model support in the LR for a good flip. 

[Bob Chill]

Excellent GEFS run today. Very supportive of the cold outbreak. Growing support for a -nao down the line. Check out some of these members. lol

 

[packbacker]

The GEFS-BC model is really cold, starting to see colder and colder starting around Xmas.

 

 

[tnweathernut]

Ok so DT says the -NAO will develop for January in his last line if I recall. For the past few days I've seen the NAO go neutral by the 25th and stay negative for the rest of the month. That's what I meant by develop by Christmas. I probably should have said this shows it can develop. It can, indeed, go negative by the Christmas. DT is just saying the -NAO will develop by January which I agree. We're talking a week here. If the NAO goes neutral on the 25th and negative by Dec 26 that's a -NAO in the current state. He's also using weekly CFSv2 means (week 3 and 4) for his analysis near the end of when the NAO will show up. I think he posted the new 00z Euro EPS at 324 showing how it's currently at +NAO at that time frame, he's correct given he buys that exact model output and run. But it's splitting hairs as the NAO was neutral by the 25th and going negative on the 12z EPS mean yesterday...so no one really knows when this will occur, saying it will develop in January is like playing the lottery and the odds are 1:1, you're going to win.

Don't get me wrong, I'd like to see it go negative yesterday, lol.  We haven't had a cooperative NAO for so long, I am not sure I will recognize it when it comes.  

[GaStorm]

Wow. P002 would produce some wild temps!

 

Excellent GEFS run today. Very supportive of the cold outbreak. Growing support for a -nao down the line. Check out some of these members. lol

 

[Jon]

Don't get me wrong, I'd like to see it go negative yesterday, lol.  We haven't had a cooperative NAO for so long, I am not sure I will recognize it when it comes.  

I agree. Here's the 12z GEFS

 

NAO:

West Based NAO:

 

Not a bad look by 12z on 12/26.

[burgertime]

OP Euro looks like the GFS with the system on the 20th. It also looks to me at the end like it's having problems resolving the upcoming pattern change looking at the SFC maps.  

[RONALD B]

The GEFS-BC model is really cold, starting to see colder and colder starting around Xmas.

https://twitter.com/DTVaWeatherman/status/543474001461673985/photo/1 DT has a train now lol .

[burgertime]

For me a really positive sign on the CMC ENS and GEFS is that you're starting to see 504 thickness sinking down into central and eastern Canada. That's a good harbinger of really cold air working it's way into the eastern United States as the PV starts to split. 

[deltadog03]

I think the extended is starting to really show itself, and thats good.  The pattern flip is coming by the end of the month.  Christmas week will probably be the flip.  I think that system for Christmas week could be some fun and games depending on how the system next weekend unfolds. 

[Jon]

On investigating the chinese model and it's verification scores (didn't find any) I found the Beijing Climate Center seasonal forecast (D/J/F) made on 11/22. Interesting. I'm going deeper than Bastardi with the JMA, but I figured some would like to see it.

 

 

[packbacker]

I agree. Here's the 12z GEFS

 

NAO:

 

West Based NAO:

 

Not a bad look by 12z on 12/26.

 

 

 

 

 

Been a long time (winter month wise) since we have seen a telecon. graph like that for the NAO.  

[Webberweather53]

 

 

Thanks guys. So, unraveling all of that, it sounds like for whatever reason, the Indian Ocean is interfering with the development of El Nino, and El Nino is not acting like a central based one...it's acting more east based.

Given that, should this negatively impact the overall expectation of a colder, stormier January and February?

Going from memory, an east based Nino is not as favorable as a west based or central based for the SE. However, in Eric's post, he indicated that the SE should not succumb to a SE ridge, so that sounded good.

 

 

I don't buy into the garbage that Modoki/west based El Ninos are better than all other El Nino types, including Hybrids. The 1969-70 east based event was generally cold & snowy from the beginning, not to mention there was a storm that dropped snow up the spine of the Appalachians around Christmas, w/ wintry weather in NC Piedmont & mountains on Christmas Day...

Christmas Day-Dec 26th 1969

"Frozen and freezing precipitation began over a large area on Christmas Day and continued the following morning. Snow was reported accumulated up to one foot in the southern Mountains and one and one half to two feet in the higher elevations of the northern Mountains as a result of this and the earlier snow. Scattered Mountain areas and much of the Piedmont had a great deal of freezing rain with the storm, causing most of the damage. There were many broken limbs, a few fallen trees, and broken power and telephone lines resulting in outages ranging from a few hours to two days in many areas. Schools were closed one or more days in several counties."

 

 

The 1982-83 strong/east based El Nino was quite snowy across the eastern US, including here in NC...

 

 

The 1972-73 El Nino was also (or at least very close to) being an east based El Nino...

We had a few nice winter storms that winter, a lesser known event in January

 

January 7-9 1973 

"Snow began in the western portions early on the 7th and spread eastward, ending in the northeast portion on the 9th. Mostly ice in the southeast and immediate coast, accumulations to three inches. Mostly snow elsewhere, accumulations in most areas four to seven inches, a few reports to nine inches. Much breakage of trees, limbs, and communication lines. Persistent cold made melting unusually slow; ground cover remained in some areas for ten days. Schools closed from one to five days in nearly all of the State's 100 counties. Several roofs and buildings collapsed from the weight of the ice and snow; much loss and damage to property. Furniture store roof collapsed in Jacksonville, Onslow County, killing one person and injuring two on January 8th. A 14,000 square foot section of warehouse roof collapsed in Lumberton on January 15, a week after the main snowfall. The harvest of soybeans, cotton and corn remaining in fields due to earlier wet weather was further delayed by snow and ice cover, with consequent lowering in quality and quantity of the crops."

 

Of course we know what happened the 2nd week of February...

 

 

[Webberweather53]

 

 

Thanks guys. So, unraveling all of that, it sounds like for whatever reason, the Indian Ocean is interfering with the development of El Nino, and El Nino is not acting like a central based one...it's acting more east based.

Given that, should this negatively impact the overall expectation of a colder, stormier January and February?

Going from memory, an east based Nino is not as favorable as a west based or central based for the SE. However, in Eric's post, he indicated that the SE should not succumb to a SE ridge, so that sounded good.

 

 

..As I've shown w/ this graphic many times before it doesn't matter what the intensity or placement of the ongoing El Nino or warm ENSO Neutral Event is, January & February are more than likely going to end up colder than normal, more so than December, which is typically the most boring month in an El Nino winter anyway...

Statistically, January & February are not only colder than December, but have more higher quality cold Januarys & Februarys, with February clearly the coldest of the 3... We've seen 36 El Nino events as defined by the ONI since 1900 (used 1971-2000 ONI climo for pre 1950 ONI record as noted by Bob Tisdale) 

(1899-1900, 1902-1903, 1904-1905, 1905-1906, 1911-1912, 1913-1914, 1918-1919, 1923-1924, 1925-1926, 1930-1931, 1939-1940, 1940-1941, 1941-42, 1951-1952, 1952-1953, 1953-1954, 1957-1958, 1958-1959, 1963-1964, 1965-1966, 1968-1969, 1969-1970, 1972-1973, 1976-1977, 1977-1978, 1982-1983, 1986-1987, 1987-1988, 1991-1992, 1994-1995, 1997-1998, 2002-2003, 2004-2005, 2006-2007, & 2009-2010)

 

& here are the statistics for Georgia, South Carolina, & North Carolina for the 108 winter months we've observed in all of those El Ninos since 1900. I used the 1895-2000 base period for the pre-1950 El Ninos then used the 1981-2010 base period for the other events to account for the general rise in temperatures that have occurred over the US within the last century or so. I defined the months that were 1, 2, 3, & 4 standard deviations from normal as those if at least one or more climate regions in GA, SC, or NC had at anomalies that exceeded +/- 1 standard deviation, +/- 2 standard deviations, etc. February doesn't just look good compared to Dec & Jan visually, but also on paper. In fact, of all the El Nino Februarys that have been colder than normal, 16 of the last 17 (2003 as the only exception) have been at least one standard deviation or more below normal somewhere in NC, SC, & GA... 

 

Here are the record holders in GA, SC, & NC by month

 

Warmest El Ninos by month: December (1923), January (1952), February (1954)

 

Coldest El Ninos by Month: December (1963), January (1977, in a virtual tie w/ 1940, however the changing base periods give 1977 the edge), February (1978)

 

I'll also mention that it's pretty rare to see December colder than normal in the southeastern US & then have both January & February end up warmer than normal & in all El Nino events since 1900, it's only happened 4 times (1952-53, 1953-54, 1997-98, & 2004-05) or about 10% of the time...

 

I thought this would be applicable to the current discussion, I'm not saying we're going to see the exact same results, but I noticed several weeks ago after the anomalous upper level low brought what was virtually unprecedented snows to the SC midlands, the uncanny similarity to 1966, which if you extrapolated into the following phase of the Lezak Recurring Cycle, led to snow on the US east coast in time for Christmas... We're still a long ways out & a lot of uncertainty remains but combined w/ -VP associated w/ the active cell of CCKW once again entering the favorable 30-60E longitude & the model guidance of course which is finally starting to show some consistency, this is interesting nonetheless.

[Jon]

Dr. Ventrice just updated his blog on the pattern change on WSI, good read: http://www.wsi.com/blog/energy/transition-back-to-a-cold-and-high-heating-demand-pattern-during-the-turn-of-the-new-year/

[deltadog03]

great post!!!

[dsaur]

Regardless, the 12Z GFS says that anyone doubting the pattern change after seeing it and other models must be on crack. It gives the SE a cooldown to near or a little below normal for 12/21-5 followed by a strong cold blast 12/26-28. The Cohen and 1939-40 analogs are liking this kind of thing fwiw.

I'm working on my 5th night cold enough for snow, and in the middle of this wretched early Dec torch, lol. That's pattern change to believe in, or rather torch bs to not believe in   Oddly enough I've only had one rain with enough heft to actually stick some, were it finding the cold air.  If I had had 5 days of some rain, to go along with the 5 days of cold enough, things would be better for timing.  So I hope your cold coming will have some rain with it, or it'll just be dry cold...and sunny and cold is somewhat akin to sunny and hot, only the ice cream works quicker to cool off your innards, lol. T

[metwannabe]

Regardless, the 12Z GFS says that anyone doubting the pattern change after seeing it and other models must be on crack. It gives the SE a cooldown to near or a little below normal for 12/21-5 followed by a strong cold blast 12/26-28. The Cohen and 1939-40 analogs are liking this kind of thing fwiw.

Larry what kind of winter did KATL have in 39-40 I went back to try and find when you posted about it and I couldn't find it

[burgertime]

LR 00z is a thing of beauty. Looks like a -AO/-NAO and a +PNA. I'll take that please. Someone better at reading maps can verify if it's a true -AO.

[deltadog03]

LR 00z is a thing of beauty. Looks like a -AO/-NAO and a +PNA. I'll take that please. Someone better at reading maps can verify if it's a true -AO.

YES, it appears that way sir!  I do like that longer range look..

[GaWx]

Larry what kind of winter did KATL have in 39-40 I went back to try and find when you posted about it and I couldn't find it

1939-40 similarities: 1) There was a late starting weak Niño that followed weak cold ENSO.

2) Solid +PDO, -AO, -NAO averaged over DJF. I'm assuming we'll get these.

3) Warm Oct., followed by cold Nov.

4) Mild dominated 12/1-19, which included two periods of +10+ days. Similar to what we're having this month.

5) Cold dominated last week of Dec. overall though not yet the frigid cold. Models suggesting this. Dec ended +1 at KATL though it was far warmer in much of the US to the west and north just like this month!

6) Frigid Jan. Second coldest month on record at KATL (barely behind 1/1977).

7) Jan. had major ZR ATL (~1" rainfall) as did nearby Cad areas in early month.

8) Jan. had a big SN for BHM-ATL-GSO as well as much of the well inland SE late month. BHM-ATL and nearby had one of its biggest SN on record with 8-10" common. Liquid eq. was ~1". GSO exceeded a foot of SN! Even MCN got 3". It had no trouble sticking to everything because of of it being very heavy as well as very cold in the days preceding it. It stayed 1"+ snowcovered for at least a week afterward at least in ATL due to extreme cold that included sub freezing highs several days as well as lows in the singles!

9) Chilly Feb. though nothing like Jan.

10) Total SN/IP for season for much of the well inland south was 200-400% of normal. That's not including the ZR.

Due to the many similarities to 1939-40, a similar kind of overall wildness/coldness starting late Dec. is very much on the table. I remain as pumped as ever for the realistic possibility of a special winter overall coming for the SE. I've already predicted one major ATL along with the nontrivial chance for two major ATL winter storms along with total of at least 3 measurable wintry events. I predicted at least -3 at KATL for DJF averaged.