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Winter Speculation 17/18 -December Thread

AMZ8990

By AMZ8990,
in Tennessee Valley

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Holston_River_Rambler

Holston_River_Rambler

Posted
Posted

To echo Carvers: I think there are so many things happening over the course of the next 7-10 days (SPV split, SSW, MJO propagation, also something with a Kelvin wave that is linked to ENSO and the MJO that I only know enough about to mention) that unfortunately we're just going to have to wait and see what happens once whatever new pattern there will be emerges. It seems to me the big hump for this is how things start to shake out once the SPV split happens. Not only that, but it seems to me models often play catch up and there is a lag between big changes in the atmosphere and how all that will effect surface conditions, so even after we get the split, it may take a bit for things to settle out. I guess what I'm saying is even if when the split happens, I'm not going to call it quits on winter if the models don't show something right away. 

I feel like we were in the middle of a reshuffle and someone stepped in, threw our cards on the floor, and said: "Nopey, time to play 52 card pick up and then you can try to reshuffle again!" 

As for the current pattern seems that it is typical Nina, as I understand it.  Warm-->rain-->cold-->repeat.  From reading others' posts it seems the Nina peaked a few weeks ago and we're now feeling those effects. Glad for the rain for now, kinda hoping for a thunderstorm too because it will be a change. Annnddddddd we can test out the thunderstorm in winter = snow soonish legend for what will hopefully be at least a chance from a new hand. We (and by this I mean folks in north Alabama - Great Eastern TN Valley) haven't had much luck with the +NAO and cold, maybe marginal temps and a semi-mythical -NAO and less mythical -AO will offer better chances. Anthony Masiello on twitter, Bob Chill from MA forum, and Carvers on here seem bullish to me on the chances for a -NAO and these are people I don't see bite usually unless there is some substance.  

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Carvers Gap

Carvers Gap

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Posted
9 minutes ago, weathertree4u said:

Interesting. I would suspect we would see more and more possibilities as the modeling incorporates changes occuring 

Yes, that look is definitely news.  As expected the Euro deepened the trough inside of 10.  That would be a major league Actic shot and would like force a -NAO.

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Carvers Gap

Carvers Gap

Posted
Posted

Just been digging around Twitter, WxBell(models and met discussions), reading the forum, looking at models, etc.  I really do not think the models past d10 have a very good handle on the upcoming pattern.  The EPS is swinging like a pendulum with the base of its trough axis from run to run.  Lots of bouncing around, though the pattern up until say Feb 20th looks like a base warm pattern.  That is when I think things may begin to turn.  I suspect there will be some fairly quick impacts of this SSW.  Cohen(I know Jeff) seems to think that the PV will split predominantly into NA.  You know, the CPC has a noticeable downturn in the AO into negative territory w the PNA going up into positive territory.  The BOMM and the ECMWF now take the MJO through phases 8 and 1 before taking it into the COD.  Both models are playing catch-up as they continue to gain amplitude into each phase after erroneously predicting de-amplification.  We are at -3.9F for temps so far for the month of Feb at TRI.  Now, some warm anomalies may erase that early next week...but still impressive for a time frame that was originally modeled to be warm.  That said, the models are really struggling at times right now.  Just no other way to say it.  So, I think this SSW is going to shake things up. I think that is why we are seeing the bouncing around much like we have seen when cold air or high latitude blocking gets put into the equation.  Now, what I don't know is how much cold there will be to tap.  When one looks at the Euro operational, it sure looks like it is positioned to dump cold into NA...but the EPS bottles it up in Canada.  To me the next couple of weeks are probably rainy and seasonable to maybe a bit warm relative to averages.  Then, the models hint that blocking may take hold.  That is a fickle animal to tame...but if that blocking exists I suspect cold will occur.  I hug the models some.  But there are trump cards that I think are strong players in the wx hobby world:  1.  ENSO trumps all others  2.  Solar (mins matter and probably many disagree) 3.  QBO state. 4.  the Pacific (PDO, PNA, EPO, WPO) 5. the Atlantic (AMO, NAO) 6.  Arctic (AO) 7. and SSW events.  The EPO has been the driver, but I suspect the SSW is about ready to take over and potentially a -NAO.  Right now the models and me are just guessing...but I suspect that we have a 2-3 week cold period during the last third of February and the first third of March.  So many unknown values for variables right now...even if the models were wall-to-wall cold, I would think that they are on shaky ground.  But a substantial number of drivers point to cold in the East after midFeb(dropping SOI, rising PNA, falling AO, hints at a -NAO, the SSW may be splitting in our favor which is the iffiest of signals, -EPO, and the concept that the base pattern of winter has been one that is cold).  There are things that are not good signals.  The WPO is looking positive which potentially means a warm Canada per JB.  The models look to have AN heights building under any eastern trough scenario.  Also, Nina climb often features a warm February.  The pattern has just not wanted to snow this winter.  Jeff mentioned the global wind where it flips the MJO phases away from what we normally expect.

All of that considered, I am going to roll with the dropping SOI, -QBO, falling AO, SSW, MJO phases, and -EPO.  Maybe throw in a wild card -NAO.  I think we have an interesting final week of Feb and beginning of March.   It does fly a little in the face of Nina climo and modeling, but I am going to bank on the Nina climbing to neutral being a or at least wash-out the Nina signal just enough.

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Carvers Gap

Carvers Gap

Posted
Posted
6 minutes ago, Holston_River_Rambler said:

Just remembered this site (I think someone on this forum pointed it out some time ago): https://earth.nullschool.net/#current/wind/isobaric/10hPa/orthographic=-85.56,82.55,414 

Might be interesting to watch the split on there.   I think the maps on there are tied to the GFS, but not sure. 

 

Yeah, impacts or not here in the forum region...still a very interesting event potentially about to unfold.

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Holston_River_Rambler

Holston_River_Rambler

Posted
Posted

So I decided to poke a little bit into recorded SSW events because of the upcoming SSW and its possible repercussions here.   Maybe this is a stretch, but there’s not much else happening other than much needed rain at this time. Below are NOAA data for recorded SSW events and which SSW events resulted in Below normal or Above normal surface temps (60 day average) for the general Tennessee Valley.  

Below are the data I found at:  https://www.esrl.noaa.gov/csd/groups/csd8/sswcompendium/

From the web page: “Anomaly fields are calculated from smoothed daily climatologies based on the full record of each reanalysis”

This is not meant to be super specific, but constitutes only what I found by eyeballing the surface Temp anomalies for our general sub-forum. Take it for what it’s worth. Some anomalies were also more anomalous than others. (ec [equal chance] = areas where I couldn't decide whether below average or above average was more appropriate) 

Below normal surface temps:

Jan 1958; Nov 1958; Jan 1960; Jan 1963; Dec 1965; Feb 1966; Jan 1968; Nov 1968; March 1969; Jan 1970; Jan 1971; Jan 1977; Feb 1980; Dec 1981; Feb 1984; Jan 1985; March 1988; Feb 1989; Feb 1999; Feb 2001; Jan 2003; Jan 2004; Feb 2008; Feb 2010

Warmer than normal surface temps:

March 1965; Jan 1973; Feb 1979; Feb 1981 ec; March 1981; Jan 1987; Dec 1987; Dec 1998; Mar 2000 ec; Dec 2001; Feb 2002; Jan 2006; Feb 2007; Jan 2009; March 2010; Jan 2013

EDIT: Judah Cohen mentions Feb 1991 on Twitter as a possible analogue for the upcoming event, but that year isn't in the above data set on the NOAA website. Not sure what that is or isn't indicate of, but throwing it out there for full disclosure. 

Now an interesting question for me, would be to compare these years and months to John’s awesome family data (if he is interested in this).  Sure each SSW event is unique, but since there’s nothing else going on for the next little bit, I thought this might be a way to pass the time and maybe gain some insight into how past SSW events impacted at least on part of the sub forum in terms of snow possibilities and cold.

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nrgjeff

nrgjeff

Posted
Posted

MJO is indeed going into cold phases. SSW is happening, and it could be a classic. China, Japan and Korea are Frozen, but recovering. That Pacific jet stream...

MJO is also crashing into the circle of death. Only two clusters of shrinking convection are noted east of the Phils and out toward the Dateline. CFS totally blew that forecast!

A particularly fast western/central Pacific jet stream appears to be blocking the MJO influence anyway, like a 7 ft center rejecting a layup with authority.

Absent other cold signals, SSW has very weak to zero correlation with North America cold. OK, maybe the -NAO but it's not as certain as the weaker correlated -AO.

I will go maybe cold I-40 north based on the -AO and perhaps -NAO. Probably nothing interesting south of I-40. Wish I could be more optimistic, but I just don't see it.

Sitting at the blackjack table after a dreadful run, I have a glimmer of hope as they shuffle. Then, I lose the rest of my money...

Remember the cold tweeters are trying to sell subscriptions. I could be totally wrong, but I need to make a call and right now it's mild.

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Carvers Gap

Carvers Gap

Posted
Posted

A good number of the people that I reference from Twitter are PhD students, professors, and/or experts in their field.  I may not always agree with all of them, but their opinions make me better...so I share.  While I certainly do this as a hobby, I don't do the one trick pony bit from folks pushing for subscriptions.  I would suggest most people have some type of angle(not implying you, Jeff) whether it be research dollars, proving a certain concept, or upward mobility within their field.  But since it is winter and finding cold patterns is part of my interest, those are folks that interest me.  

  • Dr Butler is an atmospheric scientist who works for NOAA, ESRL, and CIRES.  She works for the government.  
  • Professor Lang is in atmospheric sciences at UAlbanyDAES and focuses on synoptic to large scale dynamics.  She works for the university system.
  • Judah Cohen is a research affiliate at MIT's Parsons Lab.  He has a PhD from Columbia and worked for NASA/Goddard.  Cohen does work in the private sector as well for AER.
  • Ventrice has a PhD in tropical meteorology.  He is, indeed, a private met.  He is not a coldista, though.
  • Warner is a PhD student.  
  • I don't count Milrad....that was just a funny tweet.

And a base warm pattern is definitely on the table.  I have been cold, then warm, and now am staying at cold which I said a while back would be on shaky ground....I am just tired of flip flopping.  I am at the table playing with monopoly money since this is not my field of expertise.  Now, if things ever work over into the field of education...then that is my high ground.   If I am wrong in saying the cold is returning, I will take my lump and have no problem being wrong - taking risks is part of life I think.  I have no idea what the mean temp will be.  That is not my interest at this point.  I am simply suggesting with data that the cold will return sometime around Feb 20 and last into early March.  At least in my area, winter is rarely over in early February even during the worst of winters.

 

 

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weathertree4u

weathertree4u

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22 minutes ago, Carvers Gap said:

A good number of the people that I reference from Twitter are PhD students, professors, and/or experts in their field.  I may not always agree with all of them, but their opinions make me better...so I share.  While I certainly do this as a hobby, I don't do the one trick pony bit from folks pushing for subscriptions.  I would suggest most people have some type of angle(not implying you, Jeff) whether it be research dollars, proving a certain concept, or upward mobility within their field.  But since it is winter and finding cold patterns is part of my interest, those are folks that interest me.  

  • Dr Butler is an atmospheric scientist who works for NOAA, ESRL, and CIRES.  She works for the government.  
  • Professor Lang is in atmospheric sciences at UAlbanyDAES and focuses on synoptic to large scale dynamics.  She works for the university system.
  • Judah Cohen is a research affiliate at MIT's Parsons Lab.  He has a PhD from Columbia and worked for NASA/Goddard.  Cohen does work in the private sector as well for AER.
  • Ventrice has a PhD in tropical meteorology.  He is, indeed, a private met.  He is not a coldista, though.
  • Warner is a PhD student.  
  • I don't count Milrad....that was just a funny tweet.

And a base warm pattern is definitely on the table.  I have been cold, then warm, and now am staying at cold which I said a while back would be on shaky ground....I am just tired of flip flopping.  I am at the table playing with monopoly money since this is not my field of expertise.  Now, if things ever work over into the field of education...then that is my high ground.   If I am wrong in saying the cold is returning, I will take my lump and have no problem being wrong - taking risks is part of life I think.  I have no idea what the mean temp will be.  That is not my interest at this point.  I am simply suggesting with data that the cold will return sometime around Feb 20 and last into early March.  At least in my area, winter is rarely over in early February even during the worst of winters.

 

 

All we can do is hope! I have to say though, seeing the very very wet pattern being consistently modelled is worrisome. 

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Carvers Gap

Carvers Gap

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20 minutes ago, weathertree4u said:

All we can do is hope! I have to say though, seeing the very very wet pattern being consistently modelled is worrisome. 

I am good one way or the other.  I used to get bent out of shape during warm patterns or snowless patterns.  Now, all of it sort of interests me.  For example, the SSW may or may not impact us (see Jeff's comments above) but that is a pretty neat event.  Learning about the MJO, high latitude blocking, and ENSO state effects are also interesting to name a few.  I am definitely tired of running on very cold mornings though.  So, a warmup won't bother me.  This has been a cold start to Feb up here.  As for later this month, either it gets cold and we have something to track or I switch to flyfishing, March Madness, the Olympics and/or the garden.  Minus basketball and Olympic TV watching, those hobbies actually benefit from my wx hobby.  I don't think my ideas are grounded in hope...but that does not mean they are right either.  Part of the scientific method is building a hypothesis and testing it, right?  So like Edison, just build a light bulb and see if it works.  If not, I learn and go back to the drawing board.  Trying find to find order out of chaos is not easy and the best ideas can bite the dust quite easily.  I never bought the dry pattern for February.  The models have always hinted at the undercutting of the eastern trough by AN heights.  Our urban creeks are really high at the moment.  My normal running area had just gone above water this AM.  I slogged through mud and gunk for about a mile and then walked back another way through the shopping center areas.  There was more silt than normal.  Not sure if that is a result of the dry pattern and the creeks just had a chance to get flushed or what.  Also, I am mildly interested in the cold wx on the Korean Peninsula.  This could be one of the colder Olympics that we have seen.

I will add that having Jeff take the other side of the option is great.  It is boring if there is agreement all of the time.  I have shared this before...but in the Israeli Defense Forces (IDF), if everyone agrees upon a strategy, one member of the decision team is required to take the other side.  That prevents group think.  I think discussing weather is pretty similar.  We need folks who will challenge ideas.  Just part of science.  

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Carvers Gap

Carvers Gap

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Posted

Weeklies update....Generally I toss the 2m temps because they are generally warm as a bias...they were tonight.  Snow mean is much lower, but it has not verified at all the winter.  So the good....Looks like a -NAO becomes the principle driver of NA weather during week three and remains so for the rest of the run.  The AO goes negative.  The PNA is negative.  The WPO is generally weakly positive.  The EPO goes weakly positive.  Now, the great debate can begin.  The Pacific goes to crap but the Atlantic and the Arctic are in our favor.  The Weeklies have wanted to stick that trough in the West all winter and it just does not want to go.  I have to say it has the same look of just wanting to stick that trough their no matter what makes sense.  To me, this has more of a look what could potentially be an omega block over a good chunk of NA where we battle the SE ridge and a back and forth goes on with that.   What is interesting....the 500 pattern does not really end winter in March.  If anything, the Weeklies want to prolong winter a bit.  That is about it.  Until this SSW occurs, the models are in flux.  But overall, that pattern is a very stormy pattern where plenty of storms will be slowed and track to higher latitudes.   Verbatim, looks like Plains snowpalooza...but things could easily change.  Models often do not handle -NAOs well IMHO.  They just grind the flow to a crawl and things dig including the cold.

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Holston_River_Rambler

Holston_River_Rambler

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7 hours ago, Carvers Gap said:

I will take some of what the 0z GFS is serving up.  PV into the US in fantasy range at 252.  Might need to be in banter...but interesting for sure.

Fantasy range is all we have right now. I say cling and claw and maybe some of it will scrape off and hit us eventually ;) .  06z GFS at 186 hours, could be worse.  1040 high dropping towards the Great Lakes, moisture building in TX and OK. A low moving towards a 50/50 position. Sure the 0z CMC has a low in the same place as the 1040 high at the same time, and sure the whole thing kind of fizzles and warms as it moves east, and sure it will all change in 6 hours.

But I can dream, right? 

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Carvers Gap

Carvers Gap

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Posted

Now to some real time concerns within ten days...maybe some of our mets can chime in.  The 0z Euro IMHO is a significant flooding event if that happens.  I have seen modeled qpf numbers like this vanish, but that is hefty.  I can say that our rivers are already full up here.  It would not take much to make for some real problems.  

5a7dace75fd4f_ScreenShot2018-02-09at9_11_20AM.png.bab09411d8df6791592a32ed8913af92.png

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nrgjeff

nrgjeff

Posted
Posted

It might get ugly on non-managed rivers, creeks and streams. Fortunately the WPC has lower qpf than the Euro chart above. GFS is of course all over the place!

56 minutes ago, Carvers Gap said:

Now to some real time concerns within ten days...maybe some of our mets can chime in.  The 0z Euro IMHO is a significant flooding event if that happens.  I have seen modeled qpf numbers like this vanish, but that is hefty.  I can say that our rivers are already full up here.  It would not take much to make for some real problems.  

Long-Term the Euro weeklies are probably too warm weeks 3-4. While I'm not really excited about the SSW, we are also not going to blowtorch. -NAO starts east-based but retrogrades for North America iff the model is right.

Northeast Asia trough (downstream of Ural Mountains ridge) also returns, fixtures during cold periods. Ural Mtns ridge is quite believable with the SSW. However shorter wavelength may break USA hearts. Does the snow track skip over us from the Deep South to the Midwest? Northeast Tenn still looks OK but I continue quite bearish below 1,000 FT.

At least TGIF!

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AMZ8990

AMZ8990

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Posted
38 minutes ago, nrgjeff said:

It might get ugly on non-managed rivers, creeks and streams. Fortunately the WPC has lower qpf than the Euro chart above. GFS is of course all over the place!

Long-Term the Euro weeklies are probably too warm weeks 3-4. While I'm not really excited about the SSW, we are also not going to blowtorch. -NAO starts east-based but retrogrades for North America iff the model is right.

Northeast Asia trough (downstream of Ural Mountains ridge) also returns, fixtures during cold periods. Ural Mtns ridge is quite believable with the SSW. However shorter wavelength may break USA hearts. Does the snow track skip over us from the Deep South to the Midwest? Northeast Tenn still looks OK but I continue quite bearish below 1,000 FT.

At least TGIF!

Amen in regards to TGIF!

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