Fall 2021 Thread (September, October, November)

[Carvers Gap]

Well, we are just one season away from winter.  Nice to have a respite from the heat this week as the remnants of Ida depart the area.  Thoughts and prayers for all of those affected by the hurricane along the Gulf Coast.  Rainfall along the far eastern valley has been steady but reasonable - more as you go west I am nearly certain.  This morning features light rain/drizzle and very low cloud decks.  Lows in the northern valley are supposed to get into the 50s during the next few nights, and that is welcome news!  Saw the first evidence of maples beginning to change color this morning.  There is this one maple in our neighborhood which always changes first.  Some of the dogwoods are beginning to show red in their leaves.  Sycamores along the river are showing some yellow.  For sure, some of that could be heat stress.  Well, it is the first day of meteorological fall.  I suspect this season will feature a quick snap to winter time temps late in the season.  I am thinking warm early-mid fall, and then a sudden flip to cold.   Somebody please fire-up an obs thread and also a banter thread for fall.

 

[Windspeed]

[John1122]

This is my second favorite long range thread each year. 60 degrees out there right now and the humidity is non-existent compared to the last two weeks of drippy weather. Was looking forward to heading down to Lenoir City to actually enjoy the best weather of the young high school football season but they had to forfeit due to covid issues. BN temps and BN precip is the forecast for the 6-10 and 8-14 day CPC outlooks. As long as it's not hot and dry I'll take it. I always want to get through leaf season without a wildfire near my house, but about 2 or 3 of every 10 years they get pretty close. Last year the leaves got out of dodge here pretty fast. They were completely gone by Halloween. I went to Johnson City the first week of November and they were still awesome there. The black gum tree in my yard has had some red leaves for about a week now and the sycamore has been dropping leaves like fall already. My windshield was plastered with yellow leaves from it during the rain yesterday.

[Carvers Gap]

Seeing some much AN temps showing up in the d8-10 period - just brutal stuff.  This would easily be a record breaking heat wave for someone in the forum area.  Really, really hope I am wrong.  Looks like the hottest air of the season.  Western areas of the forum are in the bullseye for now.  Worst of summer appears still ahead.  La Nina summers are the worst.

[John1122]

The GFS looks way hotter in about a week over the Ark/La/Tex than the Euro or Canadian. The GFS is throwing out stuff about 10f hotter than those two. Oklahoma is over 110 in spots on the GFS. That heat bubbles into Memphis with 102 there. It's a big outlier right now so I have my doubts about its record heat coming to pass. 

[Carvers Gap]

The 12z Euro yesterday was not cool around the 14th.  I have been using that day as a benchmark.  The GFS has actually cooled off in E TN.  Interestingly, it was the GFS which caught the last warm-up.  I truly hope the GFS is wrong.

[Carvers Gap]

The 14th has mid 90s all of the way into northern Indiana on the 0z Euro.  The GFS has cooled considerably on this date with its 6z run.  Pulling for the 6z GFS at this point.  However, the GFS has consistently been showing incredible heat.  The Euro just recently jumped on board with a bit of a more modified(but very hot and expansive) heat wave.  There are a few solutions that sometimes manage to get a front through during that time frame.  8-9 days out, but not liking the recent majority of runs for that date.   Would certainly like to see the cooler solutions verify!

[Carvers Gap]

Other models have finally come back to normal for next week as John noted the extreme temps seem dubious.  Need the Euro to back off today, and we may have some consensus for seasonably warm temps vs crazy hot.  Temps IMBY have dropped 5-7 degrees since the earlier runs re: next Tuesday.

[Carvers Gap]

Spoke way too soon.  Models have returned this morning to near record heat for some in the forum area.  My point and click is now 93.   That is not a record high for Tuesday, but pretty sure it would be fo Wednesday.  I don't see a lot of support in modeling for that point and click, but the wx pattern with HP over us definitely supports very high temps. Really hate weather like this during fall.  It is not unprecedented, but I still don't like it.

[PowellVolz]

Spoke way too soon.  Models have returned this morning to near record heat for some in the forum area.  My point and click is now 93.   That is not a record high for Tuesday, but pretty sure it would be fo Wednesday.  I don't see a lot of support in modeling for that point and click, but the wx pattern with HP over us definitely supports very high temps. Really hate weather like this during fall.  It is not unprecedented, but I still don't like it.

2019 we had 90’s till the first weekend in October. Also in October that year, Knoxville only recorded 3 days of low temps in the 30’s and the lowest was 37°.


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[John1122]

My highest point and click is 86 over the next week. I don't see much on the 12z modeling that suggests any just crazy temperatures. Also grain of salt, but the GFS is advertising the first major cold front of fall in about 11 days or so. Looks like high temps would be in the 50s and 60s with lows in the upper 30s or low 40s. 

[AMZ8990]

It’s Starting to get chilly at the golf course with our 6am starts in the morning.  I for one am loving it.  Soil temps are starting to drop and growing season is slowing down.  Gotta love fall in the Tennessee valley 

[Carvers Gap]

To echo @John1122 in the banter, starting to see some signs of a temporary breakdown of the EC ridge complex as several storms traverse the western Atlantic and drive the cool boundary every southward.  I like it.  I like it a lot. 

[fountainguy97]

Gfs is consistently dropping a nice front through the region between the 22-24th.  Euro also agrees.  I would say this will be the first major "cold snap" of fall and will easily start our leaf season.

 

This front is only 3-5 days away from pushing across the US. Seems like it's a legit pattern coming up.

 

[Carvers Gap]

Weeklies (Euro) are showing signs of high latitude blocking towards the end of October.  Not sure we want that in place quite yet.  Would essentially mean ~6 week blocking episode if we go by 4-6 week pattern cycles.  Means mid-Dec could be warm.  Way too early to guess that.  However, early season blocking might be a good sign for winter...so there is that.  Looks to me like the summer heat is gone.

[John1122]

On 9/10/2021 at 4:45 PM, John1122 said:

My highest point and click is 86 over the next week. I don't see much on the 12z modeling that suggests any just crazy temperatures. Also grain of salt, but the GFS is advertising the first major cold front of fall in about 11 days or so. Looks like high temps would be in the 50s and 60s with lows in the upper 30s or low 40s. 

Quoting this one because the GFS handled this cool snap pretty well at D11/12. 

[John1122]

Got down to 41 this morning. Beautiful last two days. 60s yesterday and currently 66. Gonna be great football weather tonight.

[PowellVolz]

Got down to 41 this morning. Beautiful last two days. 60s yesterday and currently 66. Gonna be great football weather tonight.

28 Friday morning on Leconte


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[John1122]

Looks like boring weather will prevail the next couple of weeks. Mostly slightly AN temps overall with a cool shot or two to keep it seasonal. Some rain might get thrown into the mix with slight probs of N to AN precip in the area. As long as it's not uber dry and the fire danger is under control, I will take whatever comes the first half of the month and be happy with it, hopefully the leaves keep responding. Reds and yellows are peeking out now and one tree I saw yesterday was about half red already.

[Carvers Gap]

Euro Weeklies in addition to the seasonal CANSIPS, banging the drum for a fairly significant high latitude blocking pattern to develop later this month and into November.   Basically, a HB bay block builds into a Greenland block.  Euro Weeklies are generally always warm at the surface, but the pattern at 500 is one that would bring significantly colder air at least to the western slopes of the Apps if not all the way to the EC.  Huge grain of salt at this range, but there are hints of pattern which could produce BN temps.  Would not surprise me at all to see the first snowflakes of the season flying during the first couple of weeks of November.   But we will see.  That is my "bold" prediction for a soggy Friday morning - meaning seeing some snowflakes during November is not exactly unusual at all and pretty much right on time.

[Carvers Gap]

Euro Weeklies continue to strongly hint at an eastern trough amplification during early November(second week?).  Would involve blocking in Greenland hooking in with a PNA ridge which creates a broad area of banana high pressure over NA.  Honestly, that looks like a winter storm set-up for those a few degrees in latitude to our north and for our higher elevations.  Would not surprise me to see an early season snow in those areas.  Still likely a little too warm here due to climatology, but wouldn't be surprised to see some flakes in the air here.

[Carvers Gap]

18z GFS shows the potential for the late month pattern and early Nov pattern(though it doesn't quite get to Nov).  Deep trough amplification and a phase along the eastern seaboard which(this far out) could be anywhere.  I think the chances for a powerful coastal or inland runner are there.

[fountainguy97]

Whoever wished for fall is going to get their wish this weekend. Seems to be a permanent move to cooler weather if models are to be believed. 
 

 

@Carvers Gap I like what I'm seeing in long range models as we head into November.  A few more weeks and the first high elevation event will be on the table. 

[Carvers Gap]

A bit of a lazy comment upcoming....lots of modeling is foreshadowing cooler weather right at the end of this month and into an undetermined time frame during November.  Source region is in question.  However, pattern amplification into an EC trough is growing more likely as several models and their ensembles are supporting this pattern along with some Weeklies modeling - notably the Euro.  See commentary above and someone go get Jeff out of banter!  LOL.  j/k.  Nothing is a slam dunk at this range, and we all know modeling will often show an EC cold snap, and then it dumps into the West first.  That has been a model bias during the past several years. 

Plenty of talk of an early strat warm event.  John mentioned that in the winter thread I think.  Some great discussion there.  

[nrgjeff]

Yeah the +PNA is forecast on most models. It's a cold signal here. Source region means it could be normal vs cold; however, that's lovely fall compared to recent wx.

While the 500 mb plots look cold, 2m T forecasts are blah. Makes sense with the North much warmer than normal. Often that pattern is cloudy cool here. However northwest flow should mean more sunny mild days and cool nights. Can we have an order or three of that?

We need a mix of sunny and cloudy days for fall foliage. Sunny is always more enjoyable. However for photography cloudy has some advantages. Eh forget that more sun always!

[Carvers Gap]

On 10/15/2021 at 8:44 AM, Carvers Gap said:

A bit of a lazy comment upcoming....lots of modeling is foreshadowing cooler weather right at the end of this month and into an undetermined time frame during November.  Source region is in question.  However, pattern amplification into an EC trough is growing more likely as several models and their ensembles are supporting this pattern along with some Weeklies modeling - notably the Euro.  See commentary above and someone go get Jeff out of banter!  LOL.  j/k.  Nothing is a slam dunk at this range, and we all know modeling will often show an EC cold snap, and then it dumps into the West first.  That has been a model bias during the past several years. 

Plenty of talk of an early strat warm event.  John mentioned that in the winter thread I think.  Some great discussion there.  

Euro Weeklies for November...yep.  Looks like it pushes the potential for a better 500 pattern later into November.  Been a huge bias for several years.  At least this time we kind of knew the potential.  The good thing would be that a later flip to a more seasonal pattern would mean that much of December would be included in that pattern if one holds to 4-6 week pattern cycles during winter.

[Carvers Gap]

30 minutes ago, Blue Moon said:

Hi @Carvers Gap, thanks for sharing your observations. 1 question: what is the abbreviation EC?

East Coast.  Still looks like a major trough amplification for early November, but then reverts to a trough out West.  Now, one word of caution is that the Euro Weeklies REALLY struggle during shoulder season.  They can do quite well with individual events like next weekends EC trough, but they can miss the overall pattern at times.  I was just saying that it does not shock me to see the weeklies flip back to an western trough.  There has been a real bias of late where it places a trough over the eastern part of the US - only to have it dump the cold out West.  Honestly, I would be fine with a cold shot in early November just to get some fall weather, and then have it warm-up for a couple of weeks.  The best case scenario for a cold December is a late November flip.  But right now, huge grains of salt are called for when dealing with the weeklies.  

[Carvers Gap]

Aaaaand, the Euro Weeklies have flipped back to a cooler November just like that.  Shoulder season is a bear for models which attempt to portray patterns after the normal 16 day look.  Looks a bit blocky which might also be contributing.   Almost seemed like the last run had a similar start to the pattern, but broke it down too quickly.  Again, I would not be surprised to see the cold dump into the West and work eastward(that is much more likely in Jan and Feb).  It is decidedly colder at the surface which is unusual as it has an AN bias after week 3.  The other thing is that it was derived from a pretty cold run yesterday morning which does impact the full run.  

[nrgjeff]

Sell natural gas! Not investment advice. I'm just tired of the ECWMF weeklies choking. And don't sell natty in the face of this upward momentum. At least not today.

However the weeklies might have MJO support. Both the EC and GFS weeklies have the cooler look. Legacy CFS goes warm. Let's see which works out. Check back in two weeks. 

Please do not share the image outside of our Region.

[John1122]

While it didn't work in our favor after Nov 2019, a cool/cold November is still a good start on cold/wintry D-J-F years. So if I could choose, I'll always pick a cold November over a warm one. October has been pretty warm so far, I normally have a freeze this month but it looks like that isn't going to happen. Nothing below 37 here so far. The leaves did catch fire after last week's cold shot. They are really popping, especially maples and poplars. Hard woods are showing some color but it's still patchy.