Tennessee Valley 2019 Fall Speculation/Forecasting

[AMZ8990]

It’s early August and Football season is right around the corner, and with that so is cooler temps and the season of Fall in Tennessee.  We can use this thread to keep the summer thread free of fall/winter talk.  I hope everyone has had a good summer so far.  I’m looking forward to the upcoming months and what they possibly could bring weather wise for all of us!  

[John1122]

We are in some form of tropical monsoon pattern and it's seemingly never going to end. I would welcome lower humidity but it seems like early fall has been hard to come by lately. 

[jaxjagman]

ENSO should stay weak one way or another it seems.It's still basically a crap shoot even if it does.Sunspots from ISES  shows it peaking at it's lowest  in 22-23 winters,but that's not a giving as last winter it was much  lower than modeled plus we all expected a moderate Nino which never happened.The last lower cycle that went into 2008-2010 the ENSO was up and down but after the low solar cycle started to rise around 2010 we stayed in a more Nina pattern for ALMOST a couple years with less SSW events.Comparing last winter  into the low cycle years into the late 2000's most of the SSW events at least happened into the last part of Jan and even into Feb and not into the last part of Dec. like last year

Lots to ponder upcoming it seems to me and no realistic prediction  for a out coming based on analogs right now.IMO

[Carvers Gap]

Robert has a post on WXSouth FB about different scenarios regarding the upcoming fall and winter...is a good write-up I think.  

[AMZ8990]

On 8/12/2019 at 9:56 PM, Carvers Gap said:

Robert has a post on WXSouth FB about different scenarios regarding the upcoming fall and winter...is a good write-up I think.  

  Care to drop any nuggets??

[Carvers Gap]

1 hour ago, AMZ8990 said:

  Care to drop any nuggets??

It is free if you have Facebook.  Just search for WxSouth.  You know me...I will write a 5,000 word essay before teasing you all.  LOL. I just didn't expound since it wasn't a pay site.  Skinny...Thinks that a weak La Nina will be good...mentions TN as a being in a good spot.  All speculation he freely admits.  D'Aleo had a great post on WxBell today regarding the 93-94 analog going into fall.  Thinks that OND will be BN in terms of temps.  Also thinks that the cooler temps forecast in the LR over the northern Plains will eventually build into an eastern trough that becomes a mid-late fall stable pattern.  I am tired of the heat...so I am freely stating that I am wish casting for a some cool fall weather...or at least just dream about it.

[AMZ8990]

2 hours ago, Carvers Gap said:

It is free if you have Facebook.  Just search for WxSouth.  You know me...I will write a 5,000 word essay before teasing you all.  LOL. I just didn't expound since it wasn't a pay site.  Skinny...Thinks that a weak La Nina will be good...mentions TN as a being in a good spot.  All speculation he freely admits.  D'Aleo had a great post on WxBell today regarding the 93-94 analog going into fall.  Thinks that OND will be BN in terms of temps.  Also thinks that the cooler temps forecast in the LR over the northern Plains will eventually build into an eastern trough that becomes a mid-late fall stable pattern.  I am tired of the heat...so I am freely stating that I am wish casting for a some cool fall weather...or at least just dream about it.

Good stuff, thanks brotha.  I tried to find it on Facebook and once I did, I had trouble pulling up the article.  

[Carvers Gap]

17 minutes ago, AMZ8990 said:

Good stuff, thanks brotha.  I tried to find it on Facebook and once I did, I had trouble pulling up the article.  

Try this...let me know if it works.  If not, I will grab some snippets.  BTW, I am not completely sure what the ENSO is up to...I have a pretty detailed post in the ENSO thread.  Jax has some good stuff their recently from the JAMSTEC.  Hey, I now have access to Euro seasonal stuff!  

 

[jaxjagman]

Sea Ice is on pace to break the record back into 2012 this year,based on records from 1979.We don't know how much it can or will  reproduce right now.In the start of 2012 it started out as a weak LaNina per ONI,the first part but went more positive neutral into the summer/autumn but back to negative neutral by "OND" and stayed that way until the spring of 2014.Typically, as you see on the graph the sea ice (loss) does not really peak until Mid Sept.

Plus you have to look at the low solar this winter(some say this will be the lowest in over 200 years).I think Jeff mentioned this in another post of, but the wording wasn't the same.How will the low Ice effect the low solar this winter?

 

[jaxjagman]

In 2012 as the low ice was at it's lowest as said above it went into a more Nina pattern tho the end of the year.Really ,right now don't see this happening if you look down into the thermocline it's still warm deep down right now anyways.But,in Jan of 2013 we really toasted

[Carvers Gap]

JB shared the Euro Weeklies through September...about as warm over NA as one can get in a LR model.  Looking at Jax's Jan 2013 model and I thought it looked similar.  Check out 2019 so far over the Lower 48.  Pretty uncanny resemblance regarding the placement of warmth...also note that one is a 500 map and the other surface temp anomalies.  In some ways, I think that pattern has been in place for about eight months already.  

[AMZ8990]

On 8/16/2019 at 7:57 PM, Carvers Gap said:

Try this...let me know if it works.  If not, I will grab some snippets.  BTW, I am not completely sure what the ENSO is up to...I have a pretty detailed post in the ENSO thread.  Jax has some good stuff their recently from the JAMSTEC.  Hey, I now have access to Euro seasonal stuff!  

 

For some reason it won’t let me click on the see more tab.  I can read the first paragraph or two but that’s it.  I tried to signup for his site and that wouldn’t work either. Maybe it’s because I’m using my phone to view it

[Carvers Gap]

Fingers crossed that a nice little pattern change is being shown on the ensembles(GEFS, EPS) this morning.  Maybe the first cold front of the season around Labor Day?  Pattern change potentially arrives with that front as well.  Big ridge goes up over the West and at the very least knocks down the heat over much of the East with maybe even coastal areas getting involved over time.  Still 10+ days out there so everyone knows the rules(huge grain of salt).  The 6z GFS would be pretty awesome for the first full football Saturday of the year.  The potential for normal or slightly BN is something that a few folks have been kicking around for a week or two, so let's hope that comes to fruition...meaning fall like temps.  

[Carvers Gap]

Still looks like a nice shot of cool air is going to be here around Labor Day weekend.  Some divergence in modeling(understandably at that range) if the ridge in the East will return or be completely beat down post-Labor Day.  I am probably 50/50 on that.  Given our recent Fall patterns, the heat likely returns.  With that big ridge(EPO?)popped over the western Pacific, it likely opens the door for at least some cool air to push periodically into the SE after Labor Day.  It will depend on the amplitude of the downstream trough though.  A higher amplitude trough puts the cooler air into the nation's mid-section...a broader trough at least gets seasonal to the spine of the Apps in regards to the post-Labor Day pattern.  Basically, the skinny is that the ridge that has been so dominant of late is going to get pushed out to sea or at least to the coast by Labor Day.  The question is whether the ridge returns to the East...sometimes modeling is correct in bringing back the original pattern and sometimes it is incorrect in trying to perpetuate the old pattern.  The 0z EPS wants to have the ridge rebound while the GEFS is less enthusiastic...both within the bias of each model so who knows!  Keep an eye on the ENSO thread, some good stuff in there.  Also, Joe D'Aleo is definitely kicking around the idea that a turn to a BN pattern for the EC may return sometime in late Sept or early October.   I tend to agree just based on some digging that I have done.  But with the crazy Typoon Tip gradient in the Pacific, it is literally like trying to find your way through the dark...

[nrgjeff]

I'd intended to post several days ago; however, most people already covered my thoughts. Of course it's good to reel in the advertised cool front! What next?

I lean toward the slight rebound of the ridge and temps as Carvers discusses above. Global wind is still a little negative (less so during the cool front). However GW may dip more around Labor Day. A sharp or shorter wavelength PNA would also allow the Bermuda ridge to ooze back into the Southeast and Mid Atlantic. 

Still, I really want to be optimistic and forecast football weather for football season. Occasional slightly above normal is still football weather I would say, if we can just avoid a particularly stubborn Smoky Mtn SER.

[Carvers Gap]

Going to switch over to the meteorological fall thread from here on out.  Here is just a quick nugget from the September 1 CANSIPS.  The CANSIPS season model, which has done fairly well during the past several years(been very warm w maybe even a bias towards warm), goes normal for September(likely a bust right off the bat), warm for October, and then slowly brings in seasonal temps(some even BN) through August of next year.  I keep saying that we are way overdue for a pattern change w the current pattern being in place since almost December of last year.  That pattern has been BN temps in the northern Plains w a stout area of AN temps over the SE.  It is always good to note that models have a tendency to jump the gun on pattern changes.  Last year, the flip switched right after a very cold November.  Models last winter were notorious for trying to bring back winter, but it never did.  With the QBO now in a steady decline, I think that has to be factored in now as an indicator that is changing "phase."  That is a good sign I think.  It is just one model and we are about a month away before I truly start taking any of these models seriously...and even then still cast a wary eye at their solutions.  The biggest takeaway is progressively cooler temps over the eastern 1/3 of the country beginning in November.  The Weeklies have hinted that a change might be in the works and then pull back(might just be the same reoccurring error from last winter...might not).  I do think when the pattern ends, it actually might be foreshadowed by a couple of cold shots and then flip quickly.  Pattern change timeframe predictions are fraught with infamous busts...so I am not calling a time, just sharing output from one model.  Lastly, the Canadian may or may not be correct with its SST depiction for winter.

Also of note, the Euro seasonal is warmer over the East w a similar progression as the CANSIPS but slower by roughly a month.  It has a fairly warm December which skews as a SER when in reality it is a progressively cooler pattern each month.  Dare I even say it after the infamous fail last winter...the backloaded winter is depicted on it.  So for good vibes and because I don't trust the Euro at range right now and because I like the cooler model...I am just showing the wish cast CANSIPS.  

[jaxjagman]

Looks like a weak LaNina

[Carvers Gap]

17 hours ago, jaxjagman said:

Looks like a weak LaNina

See, I am wondering if the CANSIPS is in error?  What do you think?  Seems like it is going to have a tough time cooling off that much in the ENSO regions and its overall global ocean temps(especially the Pacific basin) again look overly cool for the second straight run.  I hadn't seen that map...good share. 

Right now, just hoping the ensemble means from this AM are on to something with breaking the overall pattern which results in a western trough at least temporarily if not permanently.   I think you used the word "crap shoot" the other day...I am pretty much in that camp for December as this warm fall is going to be tough to shake.  That said, I still like a weakly positive Nada.   

 

[Carvers Gap]

Nice to see the 12z GEFS, GEPS, and EPS Mean are in very good agreement that the eastern ridge/western trough will reverse.  Whether that verifies, no idea.  Still in the d10+range, but you can see on the Euro OP the beginning of the eastern ridge exiting w the western ridge beginning to form late in the run.  In other words, the operational models almost have the transition within d10.  Looks like(if this is actual a real opportunity) that the cold will dive into the eastern flank of the Rockies and drive SE.   Why am I happy about this?  We do not want the persistent pattern of the past 10 months to linger, and I am just plain tired of summer.  Plus, I think tracking those first cold fronts of fall are pretty interesting.  Bring on fall!!!

[jaxjagman]

On 9/10/2019 at 3:08 PM, Carvers Gap said:

Going to switch over to the meteorological fall thread from here on out.  Here is just a quick nugget from the September 1 CANSIPS.  The CANSIPS season model, which has done fairly well during the past several years(been very warm w maybe even a bias towards warm), goes normal for September(likely a bust right off the bat), warm for October, and then slowly brings in seasonal temps(some even BN) through August of next year.  I keep saying that we are way overdue for a pattern change w the current pattern being in place since almost December of last year.  That pattern has been BN temps in the northern Plains w a stout area of AN temps over the SE.  It is always good to note that models have a tendency to jump the gun on pattern changes.  Last year, the flip switched right after a very cold November.  Models last winter were notorious for trying to bring back winter, but it never did.  With the QBO now in a steady decline, I think that has to be factored in now as an indicator that is changing "phase."  That is a good sign I think.  It is just one model and we are about a month away before I truly start taking any of these models seriously...and even then still cast a wary eye at their solutions.  The biggest takeaway is progressively cooler temps over the eastern 1/3 of the country beginning in November.  The Weeklies have hinted that a change might be in the works and then pull back(might just be the same reoccurring error from last winter...might not).  I do think when the pattern ends, it actually might be foreshadowed by a couple of cold shots and then flip quickly.  Pattern change timeframe predictions are fraught with infamous busts...so I am not calling a time, just sharing output from one model.  Lastly, the Canadian may or may not be correct with its SST depiction for winter.

Also of note, the Euro seasonal is warmer over the East w a similar progression as the CANSIPS but slower by roughly a month.  It has a fairly warm December which skews as a SER when in reality it is a progressively cooler pattern each month.  Dare I even say it after the infamous fail last winter...the backloaded winter is depicted on it.  So for good vibes and because I don't trust the Euro at range right now and because I like the cooler model...I am just showing the wish cast CANSIPS.  

Still feed back problems with it.They did a upgrade with it before last month's run,it hasn't been right ever since.

[John1122]

It was too rainy here to be hot this summer, but plenty of heat this month so far. We did avoid the worst of it yesterday with a thunderstorm that fired up in the early afternoon.

[Carvers Gap]

1 hour ago, John1122 said:

It was too rainy here to be hot this summer, but plenty of heat this month so far. We did avoid the worst of it yesterday with a thunderstorm that fired up in the early afternoon.

You all have had it good.  Not sure why NE TN has been catching the brunt of the heat this summer.  We have set two consecutive record highs prior to today at TRI.  The forecast high of 95 today will smash the old record if it verifies.  Tomorrow's forecast high will be close depending on which point and click forecast are verifies - barring any storms.  So, likely three straight records with a 50/50 chance for a fourth straight.  Hopefully, once we get to next weekend...this extreme stuff is off the table for a long time.

[Carvers Gap]

@nrgjeff, I thought the Euro Weeklies from last night looked fairly decent from the last week of September through October?  I hadn't looked at them until now.  Looks like some seasonal temps at least...OR are they just pushing back seasonal temps ad nauseam?

[Carvers Gap]

Beginning to look more and more like the extreme heat will exit by next weekend, but as we have seen for the several weeks...the strong cold fronts which are modeled to form long-lasting eastern troughs are tempered down to but mere seasonal frontal passages.  I am not ready to throw in the towel yet, but my confidence is much lower that the ridge will hold in the West.  As with the last cool off in August, nice temps potentially will be in place for the last week of the month of September with hints in LR ensembles that the trough over the northern Rockies will again return.  But let's see what happens...at some point this pattern is going to change.  When it does, modeling will likely try to perpetuate the old pattern and show a faux return of the old pattern.  That said, the eastern ridge just really wants to return every, single time it has been knocked down for the past couple of nine months(excluding a few breaks in the pattern).  The longer these AN temps persist, the likelihood of having very little fall increases...meaning a flip to much cooler temps at some point.  When?  Not sure.  Let's see if modeling picks up those strong cold fronts again...sometimes modeling will lose a pattern only to regain it as it gets closer.  This is the year of reversing bad mojo...the Jayhawks are doing their part.  Now, if the wx pattern and the Vols will just do theirs!!!! 

[nrgjeff]

Yeah I think we are locked in AN temps for several more weeks. Still it won't be as bad going into Oct. Euro weeklies 4-6 probably just trending climo. CFS reloads more AN temps. Not that I trust the CFS but at least it's doing something other than punt to climo.

Global wind is still negative and looking to dip again. Only hope might be that Kelvin wave; but, I think that's just the temporary break before the reload. I'm also resigned to another crappy fall foliage year. Hell, I can do better in Kansas City.

[Carvers Gap]

5 hours ago, nrgjeff said:

Yeah I think we are locked in AN temps for several more weeks. Still it won't be as bad going into Oct. Euro weeklies 4-6 probably just trending climo. CFS reloads more AN temps. Not that I trust the CFS but at least it's doing something other than punt to climo.

Global wind is still negative and looking to dip again. Only hope might be that Kelvin wave; but, I think that's just the temporary break before the reload. I'm also resigned to another crappy fall foliage year. Hell, I can do better in Kansas City.

It is crazy that the same head fakes from last winter(admittedly haven't been watching much since April)are still presenting themselves in modeling.  There was significant cooling signaled on modeling for this upcoming weekend(in the day 10-15)...likely to be maybe to verify as maybe one or two seasonal days at best(maybe not that), but mostly a miss.  Lately, the Euro seems less inclined to take the bait of faux deepening troughs in the East....but it seems to miss the cold in the northern Plains.  The GFS/GEFS...whew...has a pretty bad cold bias in the d10-15 range.  I do know that d10-15 is sketchy at best, but at one point that time frame would give us a hint on modeling.  Not so much right now.  But yeah, you called it late last week...we'd be lucky to get back to the upper 80s or 90.  Seems like warm fall temps in place are very tough to break these days, and that is sort of Nina-esque.   We haven't had more than a sprinkle IMBY since the third week in August.  East of I-26 has received a storm or two.  Think the airport got .68(?) last week.  Anyway, these warm temps and bone dry conditions have some Nina qualities here.  With the SOI in the tank, sort of surprising there isn't more precip.  Maybe we can steal some rain from a tropical system...or this might be a pretty rough ride here with extreme temps and not much rainfall.  I do think when this flips...going to flip super cold(vs norms) similar to last November(no idea when this year) with not much transition in between it now appears.  Until then...the furnace beckons.

[nrgjeff]

Of course it'll be sudden. Having a real fall is overrated. (Note my disgust with the situation though.)

6 minutes ago, Carvers Gap said:

I do think when this flips...going to flip super cold(vs norms) similar to last November(no idea when this year) with not much transition in between it now appears.  Until then...the furnace beckons.

Interesting mid-summer models missed a couple nice fronts. However mid-summer is when the climate signal is weakest. We're hot anyway. I guess from Sept-May just assume fronts fail or under perform. 12Z Euro just went warmer 6-10 day. Do we cry or just laugh? 

[Carvers Gap]

2 hours ago, nrgjeff said:

Of course it'll be sudden. Having a real fall is overrated. (Note my disgust with the situation though.)

Interesting mid-summer models missed a couple nice fronts. However mid-summer is when the climate signal is weakest. We're hot anyway. I guess from Sept-May just assume fronts fail or under perform. 12Z Euro just went warmer 6-10 day. Do we cry or just laugh? 

12z EPS mean dumped every bit of the cold into the northern Rockies ad nauseam.  It is a never ending pattern. I will say, I am not really a model basher...just frustrated with the relentless heat we are experiencing right now.  It is far worse than anything that we experienced all summer relative to norms.  Normal high tomorrow is 79 at TRI.  Going to approach the record of 92 set in 1954...high is forecast to be 91.  Looking forward to the "cool down" this week with highs in the mid-80s which are still 5-7 degrees above normal.  Most years we would be complaining about highs in the mid-80s at this time of year...all relative I guess.  One last nugget.  The average temperature(high and lows averaged together was 75.2 for August.  It is currently 76 for September.  The average high for September is a whopping 90.2.  During August it was only 87.2.  I mean at some point this trajectory has to go down, right?  At this point I have to laugh...I am going to be freezing my tail off when it finally gets cold.  Maybe when the wavelengths change-up we will catch a break.  

[Carvers Gap]

In all seriousness, if we don't get some rain there could be serious fire issues in the eastern valley....low humidity, not a ton of precip recently, and record warm temps.

[PowellVolz]

In all seriousness, if we don't get some rain there could be serious fire issues in the eastern valley....low humidity, not a ton of precip recently, and record warm temps.

 

Sevier Co this afternoon went with a County wide no burning except for grills.

 

 

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