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Winter 2014-2015 Pattern Discussion Thread II

JoshM

By JoshM,
in Southeastern States

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Bob Chill

Bob Chill

Posted
Posted

If the SAI is really focused on Feb AO response then there were waaaay too many assumptions about the preceding months. I suppose because some years featured a -ao in Dec and/or Jan then it was easy to jump to the conclusion that given the near perfect progression in Oct that this year "should" be the same.

 

Unless things turn around in a hurry It's going to take a few successful years in a row for me to re-gain confidence in Oct SAI. I personally don't count a Feb -ao as a success if Jan ends up + on the means. But if the SAI is really geared towards Feb then it should be presented that way. I don't feel like it was at all this year. 

 

What do you guys think about the current strat progs? I see a brief split and re-consolidation by d7. 

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Webberweather53

Webberweather53

Posted
Posted

2005 and 2007 stick out like sore thumbs on there, but in a good way. Both had strong +AO through mid Jan then the -AO flipped after Jan 20th, but 2005 didn't dive until mid/end of Feb through mid-March. 2007 was really a good looking pattern from Jan 20th through end of Feb, but was real dry. You would think if it was more active it could have been more snowy. Encouraging looking at those winters.

 

 

As I also mentioned on the Banter forum, I analyzed Wilmington's Daily snowfall data going back to 1870-71, and in a +ENSO event the 50th daily percentile for snowfall is not met until February 5th, we are still 5 weeks out from reaching the halfway mark in the winter...

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deltadog03

deltadog03

Posted
Posted

GFS badly wants to give us a big ice storm around the 12th. 

I see that...I think the pattern SCREAMS ICE potential...Not snow, doesn't mean we will see anything wintry, but if we do....IMO its an icy look with all that confluence over NE and big Highs coming down into the country.  

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Webberweather53

Webberweather53

Posted
Posted

If the SAI is really focused on Feb AO response then there were waaaay too many assumptions about the preceding months. I suppose because some years featured a -ao in Dec and/or Jan then it was easy to jump to the conclusion that given the near perfect progression in Oct that this year "should" be the same.

 

Unless things turn around in a hurry It's going to take a few successful years in a row for me to re-gain confidence in Oct SAI. I personally don't count a Feb -ao as a success if Jan ends up + on the means. But if the SAI is really geared towards Feb then it should be presented that way. I don't feel like it was at all this year. 

 

What do you guys think about the current strat progs? I see a brief split and re-consolidation by d7. 

 

 

There's a physical reason why the SAI & even the MJO correlations perform better in January & February vs December, it's not just mere coincidence the data backs this up... Refer to post #1400

http://www.americanwx.com/bb/index.php/topic/45184-winter-2014-2015-pattern-discussion-thread-ii/page-40

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FallsLake

FallsLake

Posted
Posted

GFS badly wants to give us a big ice storm around the 12th. 

http://mag.ncep.noaa.gov/Image.php?image=data%2Fgfs%2F12%2Fgfs_namer_276_850_temp_mslp_precip.gif&model=gfs&area=namer&storm=&cycle=12&param=850_temp_mslp_precip&fhr=276&group=Model+Guidance&imageSize=M&ps=model&use_mins=no&preselected_formatted_cycle_date=20141231+12+UTC&scrollx=0&scrolly=0

 

and continues to hr 300:

http://mag.ncep.noaa.gov/Image.php?image=data%2Fgfs%2F12%2Fgfs_namer_300_850_temp_mslp_precip.gif&model=gfs&area=namer&storm=&cycle=12&param=850_temp_mslp_precip&fhr=300&group=Model+Guidance&imageSize=M&preselected_formatted_cycle_date=20141231+12+UTC&ps=model&use_mins=no&scrollx=0&scrolly=0

 

Even with this being a fantasy at this point, not sure we would want this...   

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Bob Chill

Bob Chill

Posted
Posted

There's a physical reason why the SAI & even the MJO correlations perform better in January & February vs December, it's not just mere coincidence the data backs this up... Refer to post #1400

http://www.americanwx.com/bb/index.php/topic/45184-winter-2014-2015-pattern-discussion-thread-ii/page-40

 

I know december is a wildcard month. I've read Cohen's work. But things aren't anywhere near expectations so far and it looks to get worse before getting better in the ao/nao dept. If the upcoming +ao regime has legs and holds a +2sd for a decent period then the chances of getting a -ao winter on the means is going to be awfully tough. I've always thought that the opi and sai are all about predicting a -ao or +ao winter as a whole. Of course each individual month will behave with it's own personality and a -ao for all 3 months is pretty rare but at the end of DJF everyone (pro and weenie alike) predicted the AO to average negative. There is plenty of time for that to happen but changes need to start pretty quick.

 

I've been doing this insane routine for too many years and the only certainty is uncertainty. 

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packbacker

packbacker

Posted
Posted

If the SAI is really focused on Feb AO response then there were waaaay too many assumptions about the preceding months. I suppose because some years featured a -ao in Dec and/or Jan then it was easy to jump to the conclusion that given the near perfect progression in Oct that this year "should" be the same.

 

Unless things turn around in a hurry It's going to take a few successful years in a row for me to re-gain confidence in Oct SAI. I personally don't count a Feb -ao as a success if Jan ends up + on the means. But if the SAI is really geared towards Feb then it should be presented that way. I don't feel like it was at all this year. 

 

What do you guys think about the current strat progs? I see a brief split and re-consolidation by d7.

I am beginning to think that my expectations for wall to wall -AO was unrealistic. If we do get a flip to strong -AO after Jan 20th or through end of Feb it's going to tough to argue the SAI didn't have some influence, especially based on Webbers post above. But, I think it needs to be strong. When you look at 2005/2007 the AO did flip and went strongly negative. I don't think the current warming being progged will be the death blow, we will need another strong round in mid-Jan.

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packbacker

packbacker

Posted
Posted

I know december is a wildcard month. I've read Cohen's work. But things aren't anywhere near expectations so far and it looks to get worse before getting better in the ao/nao dept. If the upcoming +ao regime has legs and holds a +2sd for a decent period then the chances of getting a -ao winter on the means is going to be awfully tough. I've always thought that the opi and sai are all about predicting a -ao or +ao winter as a whole. Of course each individual month will behave with it's own personality and a -ao for all 3 months is pretty rare but at the end of DJF everyone (pro and weenie alike) predicted the AO to average negative. There is plenty of time for that to happen but changes need to start pretty quick.

 

I've been doing this insane routine for too many years and the only certainty is uncertainty.

I also think we (entire EC) have been unlucky to hit the worst case setup/scenario for the start of this winter. I am bored to tears, I know I got sucked in listening to JB, won't happen again.

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Bob Chill

Bob Chill

Posted
Posted

I also think we (entire EC) have been unlucky to hit the worst case setup/scenario for the start of this winter. I am bored to tears, I know I got sucked in listening to JB, won't happen again.

 

December didn't bug me too much. What I'm seeing for Jan is starting to grate on my nerves. Models tossed a bone a week ago when it looked like meaningful blocking could show it's face around this time. But instead we are still facing deep shades of blue all over the areas we wan't pretty yellows and reds. It's worrysome that the nao is in such a stable + state. It won't go away quickly. 

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Webberweather53

Webberweather53

Posted
Posted

I know december is a wildcard month. I've read Cohen's work. But things aren't anywhere near expectations so far and it looks to get worse before getting better in the ao/nao dept. If the upcoming +ao regime has legs and holds a +2sd for a decent period then the chances of getting a -ao winter on the means is going to be awfully tough. I've always thought that the opi and sai are all about predicting a -ao or +ao winter as a whole. Of course each individual month will behave with it's own personality and a -ao for all 3 months is pretty rare but at the end of DJF everyone (pro and weenie alike) predicted the AO to average negative. There is plenty of time for that to happen but changes need to start pretty quick.

 

I've been doing this insane routine for too many years and the only certainty is uncertainty. 

 

 

It all has to do w/ the seasonal amplitude of the wintertime jet & planetary waves which peak in January, and the after-effects lingering on the PV well into Feb... The upcoming +AO regime is a direct response to the MJO which passed through the Indian Ocean last week, there's a large array of literature that shows the AO lags signals in tropical convection, & what we're seeing now is no different, and we'll probably see the AO come down not only due to downwelling of + stratospheric temp anomalies, but the MJO moving back into the Pacific will quell the punctuated increase in the NAM...

 

It's actually not rare nor unusual whatsoever to have a -AO averaged for all 3 months of meteorological winter (DJF). It has happened 21 times since 1950 (~30-35% of the time or about once every 3 years)... including 1950-51, 1952-53, 1955-56, 1959-60, 1962-63, 1964-65, 1967-68, 1968-69, 1969-70, 1970-71, 1976-77, 1977-78, 1978-79, 1980-81,1985-86, 1993-94, 1997-98, 2000-01, 2005-06, 2009-10, & 2012-13

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/monthly.ao.index.b50.current.ascii.table

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CAD_Wedge_NC

CAD_Wedge_NC

Posted
Posted

 

I've been doing this insane routine for too many years and the only certainty is uncertainty. 

 

  Just when you think you have all of life's answers, they change all of the questions. Take last year for example, we thought for sure it was going to wall-to-wall warm. Look how it turned out... this year we felt fairly confident that it would be cold... I still believe that we will turn the corner, but who knows if we will make up for December. However, I don't see it waiting until late January to turn cold.  The only thing that scares me is the MJO. Although some have argued that it has little bearing on our weather, I would rather see it in phases 7,8, or 1 than where it is now.

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