Jump to content
  • Member Statistics

    17,585
    Total Members
    7,904
    Most Online
    23Yankee
    Newest Member
    23Yankee
    Joined

Winter 2014-2015 Thread


Ji

Recommended Posts

Definitely disagree with his analog selections. Some of those years are just baffling to me, but I wish him good luck. I'd take my chances with a pattern like that.

Agreed on the analogs. Also kinda weird his use of verbiage like...hot and dry. Ok maybe temps will be above normal in the NW, but is it really going to be HOT in winter in western and central Montana? Maybe I am nitpicking.

Link to comment
Share on other sites

  • Replies 2.1k
  • Created
  • Last Reply

Way too much obsession with Nino 3.4 SSTs here. Look at the AAM tendency & gradual poleward propagation over the last 8 months. We might as well be in a moderate Niño right now.

 

 

 

The past year was certainly Nino-like in terms of the AAM budget (the spike in early spring was akin to a robust moderate Nino), I agree, though the past several weeks have seen a slip into more -AAM values. I think we'll likely neutralize in the longer term, and potentially see periods above 0.

 

glaam.sig.seascyc.png

Link to comment
Share on other sites

The past year was certainly Nino-like in terms of the AAM budget (the spike in early spring was akin to a robust moderate Nino), I agree, though the past several weeks have seen a slip into more -AAM values. I think we'll likely neutralize in the longer term, and potentially see periods above 0.

There's a lot more here than superficial +/-'s, though. We've seen a gradual poleward AAM propagation/displacement over the last 8-12 months. Walker Cell has weakened overall and migrated eastward. As a result, you're seeing a classic east-based Nino look over the NH...most notably the GOA troughing, warm central/northern US, etc. That's classic Nino.

Based on tropical forcing, I believe the US will be devoid of any Arctic air until mid or late November, when we'll probably see a pseudo -EPO try to get going temporarily. But even then, I don't think winter will truly lock in until January. Should be a SSW/PV breakdown in late December or January, followed by a deep -AO probably centered around the heart of winter (Jan, maybe Feb as well)?

Link to comment
Share on other sites

Yeah it is. I looped it from Sept 30 till today. Its on the move. Lets see if it can keep expanding at a good clip or if it craps out. 

although I haven't looked closely, many are saying the models are predicting more snowfall over the areas that count in the coming 10-14 days

hopefully that's the case

AO wants to be nowhere but negative too

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.sprd2.gif

Link to comment
Share on other sites

There's a lot more here than superficial +/-'s, though. We've seen a gradual poleward AAM propagation/displacement over the last 8-12 months. Walker Cell has weakened overall and migrated eastward. As a result, you're seeing a classic east-based Nino look over the NH...most notably the GOA troughing, warm central/northern US, etc. That's classic Nino.

Based on tropical forcing, I believe the US will be devoid of any Arctic air until mid or late November, when we'll probably see a pseudo -EPO try to get going temporarily. But even then, I don't think winter will truly lock in until January. Should be a SSW/PV breakdown in late December or January, followed by a deep -AO probably centered around the heart of winter (Jan, maybe Feb as well)?

 

 

Yeah, there's certainly much more to it than the numbers, as is the case with any teleconnection index for that matter. I'm curious as to your thought process regarding the second paragraph. Are you utilizing the behavior of the GWO and/or MJO in formulating those opinions? And with regards to the possible stratospheric warming / PV disruption, namely, the delayed occurrence of said events, are you basing this on QBO progression and expected solar trends (or typical climo for +ENSO/-QBO seasons with heightened solar activity)?

Link to comment
Share on other sites

Just did a comparison of winters following Septembers with high and low North American snowfall extent:

Low:

C_Kw1vultI.png

High:uBFM3MWtZh.png

 

Not sure what exactly this is picking up on. I doubt it is as important as the SAI but its still good to have on our side.screenhunter_3455-oct-08-22-43.jpg?w=640

that's some good shiat right there

forget that some of the years with high September snowfall were not that great for snow around here, what it clearly shows in the means is an Alaskan Ridge, a decent -NAO, and a weak -AO (if my weenie eyes are seeing it correctly)

Link to comment
Share on other sites

the record for NH snow cover at the end of October is 1976, with 10/02 coming in at 2nd

obviously, a lot can happen between now and 10/31, but below are maps for 10/12/02 (top) and 10/12/14 (bottom)

they look comparable in toto, but this year is definitely better in Eurasia and all areas south of 60N to my eyes

 

ims2002285.gif

 

cursnow.gif

Link to comment
Share on other sites

don't know how much it may mean to our winter, but sea ice is pretty good vs. recent years

the link below is an interactive map; click on the year on the right and it highlights it on the map

this year (bright yellow) is about right on top of last year at this time and we're doing better than 2009 fwiw

http://arctic.atmos.uiuc.edu/cryosphere/arctic.sea.ice.interactive.html

 

you can scroll over the graph too for detailed daily info

Link to comment
Share on other sites

I assume it's the GFS, but I found these 7 days arctic 500mb anomaly and 850mb temp forecasts

pretty cool as they show additional snowfall in Asia; keep in mind as well (fellow weenies) that surface temps around the arctic often are colder than 850 temps, especially during the winter months

http://globalweatherlogistics.com/seaiceforecasting/gfs.500mb.height.anomaly.arctic.html

http://globalweatherlogistics.com/seaiceforecasting/gfs.850mb.temps.arctic.html

Link to comment
Share on other sites

I'd like to see a little of that Eurasian snow melt and then explode again during the last week of the month.

Yeah, the danger with rapid snow cover build up over Siberia is that it could displace the PV over Eurasia for extended periods, more than what we would like. The Canadian side is really lacking, but still near average.

Link to comment
Share on other sites

I'd like to see a little of that Eurasian snow melt and then explode again during the last week of the month.

although all of us (weenies) probably share your concern, but last year had a build up late SEPT-OCT and then we lost it and things worked out for us

and as Millwx said a few weeks ago, the more the merrier wherever and whenever it may fall (I'm paraphrasing Millwx, so if I'm wrong, please feel free to correct me Millwx)

Link to comment
Share on other sites

although all of us (weenies) probably share your concern, but last year had a build up late SEPT-OCT and then we lost it and things worked out for us

and as Millwx said a few weeks ago, the more the merrier wherever and whenever it may fall (I'm paraphrasing Millwx, so if I'm wrong, please feel free to correct me Millwx)

Agreed. I'm not really concerned, but the balance of evidence shows that a late increase would make us a little happier.

Link to comment
Share on other sites

Agreed. I'm not really concerned, but the balance of evidence shows that a late increase would make us a little happier.

 

It's a near best case scenario so far for the whole SAI stuff. NA ended sept with a record but it has dropped to just above average. All models shows the extent in the western half of Canada to increase southward over the next week or so. Some signs of eastern Canada getting appreciable snowfall too but that probably doesn't mean much. 

 

Everything looks solid. SAI going well, strong anomaly south of the Aleutians, +PDO gaining traction. I don't see any cause for concern yet. We're still over a month away before December has any clarity anyways. 

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...