2014-15 winter outlook

[jburns]

Cold and snowy = pinned.    

 

Nice job.

[Ridgebridge]

Folks,

Red hot off of the press: Cold average for each month from Nov. through March per Larry Cosgrove. Epic winter being predicted at least on par with cold of 2009-10.

Month ATL RDU

Nov -5 -4

Dec -5 -5 with possible winter storm (note that ATL is so overdue for a major Dec. SN/IP...last one 1917)

Jan -5 -5 dry

Feb -6 -6 snow threats in the area

Mar -4 -4 risk for winter storm from bowling ball

DJF -5.3 for ATL and RDU.

Entire SE similar. So, please don't ask for what he has for your hometown. He'll obviously be tested very soon for Nov.

Where can we read his forecast

[GaWx]

Where can we read his forecast

 

Through 11/3, anyone can see it here:

 

https://twitter.com/LarryCosgrove

[Cold Rain]

The OPI finishes strong at -2.08.  I Don't know what the SAI/SCE finals are yet, but they'll be big, even though it looks like there has been some melting into the close.  But regardless, the damage has been done.  The AO average for the month will be negative.  That index looks to rise and then potentially fall back below 0 down the road.  And the building of Nino continues....

 

This month saw developments, almost to perfection, portending to a cold winter.  We also read a multitude of probably the coldest and snowiest winter forecasts we have ever seen for one season -- maybe the coldest and snowiest we'll ever see.  So as we bring October to a close in the specter of a chilly Halloween night, we welcome November with a highly anomalous storm, with the first flakes of the season looming on the horizon for parts of the southeast!

 

Who knows what the next chapter holds, but for now, right now, I can't imagine feeling any better about what is to come.  Let the march toward winter commence!

[buckeyefan1]

The OPI finishes strong at -2.08.  I Don't know what the SAI/SCE finals are yet, but they'll be big, even though it looks like there has been some melting into the close.  But regardless, the damage has been done.  The AO average for the month will be negative.  That index looks to rise and then potentially fall back below 0 down the road.  And the building of Nino continues....

 

This month saw developments, almost to perfection, portending to a cold winter.  We also read a multitude of probably the coldest and snowiest winter forecasts we have ever seen for one season -- maybe the coldest and snowiest we'll ever see.  So as we bring October to a close in the specter of a chilly Halloween night, we welcome November with a highly anomalous storm, with the first flakes of the season looming on the horizon for parts of the southeast!

 

Who knows what the next chapter holds, but for now, right now, I can't imagine feeling any better about what is to come.  Let the march toward winter commence!

Well said    

[GaWx]

The OPI finishes strong at -2.08. I Don't know what the SAI/SCE finals are yet, but they'll be big, even though it looks like there has been some melting into the close. But regardless, the damage has been done. The AO average for the month will be negative. That index looks to rise and then potentially fall back below 0 down the road. And the building of Nino continues....

This month saw developments, almost to perfection, portending to a cold winter. We also read a multitude of probably the coldest and snowiest winter forecasts we have ever seen for one season -- maybe the coldest and snowiest we'll ever see. So as we bring October to a close in the specter of a chilly Halloween night, we welcome November with a highly anomalous storm, with the first flakes of the season looming on the horizon for parts of the southeast!

Who knows what the next chapter holds, but for now, right now, I can't imagine feeling any better about what is to come. Let the march toward winter commence!

I couldn't have put it much better than this. Don't forget the all important +PDO. I wonder how low that OPI is vs. other Oct 's. Being a stats and numbers crunching guy, I'd love to know.

I love autoincorrect! Isn't it great?

[Cold Rain]

Well said  

 

Thanks!  Can't wait for some !

 

I couldn't have put it much better than this. Don't forget the all important +PDO. I wonder how low that OPI is vs. other Oct 's. Being a stats and numbers crunching guy, I'd love to know.

I love autoincorrect! Isn't it great?

 

Yeah, I totally forgot about the PDO.  Good developments there.  I was wondering the same thing about other October OPIs too.  Maybe they will tell us.  And autoincorrect is the best!

[griteater]

^ You can estimate the OPI for prior years here...we should be right at the 2nd lowest on record, similar to SAI and SCE

 

[GaWx]

^ You can estimate the OPI for prior years here...we should be right at the 2nd lowest on record, similar to SAI and SCE

 

Thanks, Grit. I still am amazed at how high the correlation is for OPI to DJF -AO! I hope it is 100% legit!

[GaWx]

 By my math, the Oct. AO will come in almost exactly at -1.0

[LithiaWx]

^ You can estimate the OPI for prior years here...we should be right at the 2nd lowest on record, similar to SAI and SCE

 

Can you please source this? I have a hard time buying the correlation is that strong.

[griteater]

Can you please source this? I have a hard time buying the correlation is that strong.

 

Marietta - your skepticism is well warranted.  Last year was the first time the group made a forward based forecast, and it was their biggest bust.  The OPI last Oct was +1.60 and the DJF AO was +0.2.  While not a colossal bust, it was a bust.  Their high correlations have all been part of their research / hindcasts.  Having said that, I like the work they are doing.  Based on what I read last year about the OPI, the number is a calculation based on the daily 500mb pattern in Oct...with the premise being that Pattern X is more favorable for disrupting the stratospheric polar vortex when it is in its infancy stage in Oct, and pattern Y is less favorable for disrupting the early polar vortex.  More disruption in Oct favors a weakened polar vortex during winter (-AO), while less disruption in Oct favors a strengthened vortex during winter (+AO).  All of this is similar to the Siberia snow advance research (the OPI team was suppose to be working together this past year with Cohen who did the snow advance work), but one of the claims of the OPI team was that their method was even better in that it could outperform the snow advance index.  Coming off the bust from last year, we obviously have to wait and see how it performs going forward.

 

This thread on the OPI from last Oct has the graph -  http://www.americanwx.com/bb/index.php/topic/41379-october-pattern-index-predicting-winter-ao-from-october-with-90-accuracy/

[Harry]

Can you please source this? I have a hard time buying the correlation is that strong.

 

 

Didn't it fail last winter when it was predicting a hugely positive AO which ended up about neutral?

[packfan98]

It seems like for most of the past ten years there has been a new feature that the mets. focus on for predicting (NAO, ENSO, MJO, QBO, Analogs, etc...).  It also seems like there is also one (sometimes more than one) major "fly in the ointment" that overwhelms the pattern and makes the pre-winter seasonal predictions look silly (Crappy Pacific, no blocking, etc...).  With most every met seeing these signals pointing to a cold and wintery East, what the most likely signal that could overwhelm the pattern and ruin these predictions?

[Cold Rain]

It seems like for most of the past ten years there has been a new feature that the mets. focus on for predicting (NAO, ENSO, MJO, QBO, Analogs, etc...). It also seems like there is also one (sometimes more than one) major "fly in the ointment" that overwhelms the pattern and makes the pre-winter seasonal predictions look silly (Crappy Pacific, no blocking, etc...). With most every met seeing these signals pointing to a cold and wintery East, what the most likely signal that could overwhelm the pattern and ruin these predictions?

There is a fabulous post in this thread addressing that very question. Check it out:

http://www.americanwx.com/bb/index.php/topic/44781-winter-2014-2015-possible-scenarios/#entry3106732

[packfan98]

There is a fabulous post in this thread addressing that very question. Check it out:

http://www.americanwx.com/bb/index.php/topic/44781-winter-2014-2015-possible-scenarios/#entry3106732

 

Thanks for the link CR.  Here is the best post in the thread

 

 

There are a number of questions/"ifs".  I think NONE of them will come back to bite us (and I'll say why), but they COULD...

 

1) QBO being TOO negative.  Some studies have shown that the QBO being TOO negative can actually help make for a stronger polar vortex... NOT what we want to see.  Why I don't think this will be a problem:  QBO appears to be peaking; we may see it start coming off as early as the Nov reading.  Plus, the sample for "extreme" QBOs is pretty small... so, the research on this is a little dubious.

 

2) Solar activity being high.  We're near a solar peak, which is never good for winter.  Why I don't think this will be a problem:  Though we're near a peak, it's a peak embedded within a larger low activity stretch.  So, it's only relatively a peak.  I'm hard pressed to believe such a lame peak is going to override all other factors.

 

3) NE Pac cooling.  The GOA has cooled a lot recently; this isn't something you want to see.  Why I don't think this will be a problem:  Several reasons... First, though much cooler, it's still mostly warm.  Second, the forecast near-term pattern is less favorable for additional cooling (not sure it supports re-warming, but the cooling trend should slow or stop).  Third, all model projections keep it warm.  And fourth, you can make a chicken and egg argument here - but if you look at 2002 only the extreme eastern GOA stayed warm, and the U.S. pattern looked similarly east-shifted... tons of warmth all the way into the Plains... BUT, the East remained cold.  That might be more effect than cause... but if one believes there to be at least a minimal causation, that's important because, at least in the near-term, related to my second point, the pattern should support maintaining or warming the temps in the far eastern GOA.  The rest of the GOA is less certain, but the eastern GOA should stay warm - which MAY be all that matters to us here in the East.

 

4) Raging Nino.  Plausible?  I suppose.  Why I don't think this will be a problem:  Though plausible, no one is expecting this.  And no model projects it.  And given the recent track record, one should be more inclined to assume the Nino UNDER-performs.  So, this is a pretty strong unlikelihood.

 

The one thing I could see being an issue this winter... I have several analog seasons that are dry.  I could easily see this winter being cold and dry.  But most of my analogs aren't extreme on the dry side.  And since ptype is an issue - at least occasionally - for most, a little dry and cold probably still yields near normal snow (maybe even above in the warmer locales).  And I'm not convinced it'll be dry (there is huge variance in my analogs on precip; much less variance on temps).  So, POTENTIALLY, dryness could be a problem, which I think would get a lot of folks on this board depressed... if we get all the cold and few storms.  But I'm not convinced that'll be a problem either... just a possible issue.

 

So, there are a number of issues that could mess with our winter.  But I don't expect any of them to (obviously.... or my forecast wouldn't be cold).

 

[Cold Rain]

^ NP. Millwx is all in on the cold winter too, as you can tell.

[packbacker]

Thanks for the link CR.  Here is the best post in the thread

 

 

Been a lot of talk of the QBO rising to neutral or atleast approaching "neutral", which DT has good numbers on how a negative QBO that rises to neutral range (+8 to -8) has a high probability of a -NAO.

 

Looks like the cooling in the NE Pac has stopped, for now atleast, and there has been some nice warming.  JB talked about this in his Saturday summary that once the AK low moves west over the Aleutian islands it will stop the cooling in the NE Pac.

 

http://www.tropicaltidbits.com/analysis/cdas-sflux_ssta7diff_global_1.png

 

I think a weak Nino looks good, although the CFSv2 believes it cools some by Jan.

[griteater]

October PDO from NOAA is in at +1.28.  That's the 15th highest Oct value for NOAA PDO data back to 1857 (15/161 years)....and the 12th highest if going back to 1900 (12/115 years).  Univ. of Washington PDO will come out sometime later in the month.

 

Here's the progression of the NOAA PDO since June:

Jun: -0.12

Jul: +0.15

Aug: +0.16

Sep: +0.58

Oct: +1.28

 

ftp://ftp.ncdc.noaa.gov/pub/data/cmb/ersst/v3b/pdo/pdo.dat

[Kory]

With the monster Aleutian storm to in the coming days, I suspect a significant reinforcement/continuation of a +PDO configuration. Good chance it'll likely stay very positive through the winter also.

[GaWx]

October PDO from NOAA is in at +1.28.  That's the 15th highest Oct value for NOAA PDO data back to 1857 (15/161 years)....and the 12th highest if going back to 1900 (12/115 years).  Univ. of Washington PDO will come out sometime later in the month.

 

Here's the progression of the NOAA PDO since June:

Jun: -0.12

Jul: +0.15

Aug: +0.16

Sep: +0.58

Oct: +1.28

 

ftp://ftp.ncdc.noaa.gov/pub/data/cmb/ersst/v3b/pdo/pdo.dat

 

 With the NOAA Oct PDO at +1.28, that means that the Univ. of Washington Oct PDO has a realistic shot at being near a whopping +1.75, which would be the third highest on the table next to 1934 and 1936.

[GaWx]

 I added wintry precip. to my analysis of KATL Novembers in the fall thread that showed that the best best for a cold winter would be that Nov. not be warm in relation to the subsequent winters (as per the top heaviness of the cold winters in the list).

 I looked at anything from high end neutral positive through low end moderate El Nino (33 winters) at KATL. Here is what I found for the respective winters going from coldest Nov. to warmest Nov.:

 

Year/Nov. mean/Winter

1976/44.2/cold 1.0"

1911/47.0/cold 5.2" & a major ZR

1880/47.3/cold ~6.0"

1951/47.5/warm 3.9"

1923/49.8/norm 4.0"

1969/50.1/cold 0.6"

1968/50.1/cold 2.2"

1936/50.1/warm 0.0"

1939/50.2/cold 8.3" & a major ZR

1885/50.5/cold little SN/IP but a moderate ZR

2002/50.9/norm T & a moderate ZR

1884/51.3/cold ~11" & a major ZR

1963/51.5/cold 3.6"

1904/51.6/cold 1.0", 2 major ZR's, & 1 moderate ZR ,

1929/51.8/warm 5.1"

1914/52.4/cold 1.4"

1895/52.4/norm 0.2"

1953/52.7/warm 0.1"

1952/52.8/warm 1.3"

1900/52.8/norm 4.4"

2006/53.8/warm 0.1"

1935/53.8/cold 10.9" & 2 major ZR's

1979/54.3/norm 4.4"

1977/54.3/cold 0.3"

1913/54.8/norm 4.4"

1927/55.7/norm 0.2"

1919/55.7/norm 0.1"

2004/56.4/warm 0.5" & a major ZR

1990/56.5/warm 2.1"

1958/56.5/norm 2.4"

2003/57.6/norm 2.5"

1986/57.9/norm 4.8"

1994/58.3/warm 0.4"

 

 The 13 cold winters averaged 4.0” (200% of normal) & there were a whopping 7 major & 2 moderate ZR’s during them! An impressive 5 of 13 (38%, which is nearly twice the climo of 20% for all winters) of these cold winters had at least one major ZR. The 11 near normal winters averaged 2.5” and there was only one moderate ZR. The 9 warm winters averaged only 1.5” and there was only one major ZR (11% of the winters). So, the cold winters in this list produced almost 3 times as much SN/IP at KATL as warm ones and a much higher frequency of ZR in ATL. That's one reason to hope November isn't warm since cold winters have tended to not follow warm Novembers.

 The winters following the top 11 coldest Nov.’s averaged 2.8” and had a total of 2 major (over 2 winters or 18% of the 11) as well as 2 moderate ZR’s. The winters following the middle 11 Nov.’s averaged 3.6” and had a total of a whopping 5 major (over 3 of the winters or 27% of those 11) as well as a moderate ZR. The winters following the top 11 warmest Novembers averaged 2.3” and had a total of only one major ZR (11% of those winters).

 All of this is telling me that keeping KATL's November no warmer than ~54 would be beneficial to winter's wintry precip. prospects and that it being near the 50-52 range (near to slightly below normal) may be the sweet spot, especially considering the frequency of ZR.

[packbacker]

Interesting post from Brad P. on CLT's prospects in Nino's.  Looks like he was supposed to release his winter forecast but haven't seen it yet.

 

For reference, below is RDU's numbers...

 

RDU:

Nino's - 7.2"

130 yr - 7.2"

50 yr - 6.9"

10 yr - 3.7"

 

[Cold Rain]

Matt East put out a winter forecast yet?

Pack, let's start turning that 10 year around this year, huh?

[burgertime]

I didn't watch Brad P. last night but my friend at work basically said he was calling for cold and wet. Below average temps with above average precip. 

[Shawn]

I think there is a consensus between pretty much all credible forecasts that it's going to be colder and wetter than normal in the SE.

 

On a side note, I caught something on the news last night where they were saying that an early snow from SC & the NE a couple days ago meant it was going to be a hot winter.  I just sat here and chuckled and wondered if they even understood how it even snowed that far down here and how brief it was.

 

Right before that, our local met was asked if it was a sign of the kind of Winter and he's basically like "no, 7-10 days at a time".

[buckeyefan1]

I didn't watch Brad P. last night but my friend at work basically said he was calling for cold and wet. Below average temps with above average precip. 

Brad P tracks  

With these storm tracks it should be wet, but if the ohio valley track remains the dominate one, ice could be a concern for the cad areas      Either way, I like his forecast for slightly below avg temps and slightly above avg precip   

 

[Shawn]

I just got around to looking at the EPS Weekly Control Run.  It's too far off to really believe much.. but the first week of December has the entire Southeast going off the charts with cold 850 anomalies.  Hopefully Larry can get a look at it soon.

 

Again, it's so far away, it's worthless.  But not a bad sign.

[FallsLake]

Brad P tracks  

With these storm tracks it should be wet, but if the ohio valley track remains the dominate one, ice could be a concern for the cad areas      Either way, I like his forecast for slightly below avg temps and slightly above avg precip   

 

I would say that this is a very logical depiction of a storm track; even if your going with a cold winter. If the primary was off the coast it would be insane (..snow wise). As you stated even the primary track could cause major SE ice events. (so) I would take this forecast in a heartbeat.   

[GaWx]

I would say that this is a very logical depiction of a storm track; even if your going with a cold winter. If the primary was off the coast it would be insane (..snow wise). As you stated even the primary track could cause major SE ice events. (so) I would take this forecast in a heartbeat.

Falls,

Agreed. It is very rare for the classic Miller A major SE snow producing stormtrack to be primary. In a typical great SE snow winter, the widespread snow is typically a result of 1-2 Miller A's with only a few winters having 3 to maybe 4 that produce widespread SE snow as I think may have been the case in 1894-5 and 1884-5 among a few others. So, my point is that about the best to hope for is to have the Miller A track be secondary (typical of great SE snow winters) with very rare exceptions at most.