Fall 2021 Thread (September, October, November)

[nrgjeff]

Good morning @Mr. Kevin I will never dispute a warmer than normal forecast. Trend. But I try to offer hope.

Pacific teleconnection roundup is robust! Do not share outside our region though. Valid after Day 15, but not really a forecast.

[fountainguy97]

I'm not saying there is a chance but.... most GEFS members bring a NW event on the tail end of this mid November system. 
 

still way out in no man's land for now .

[Carvers Gap]

Way, way out there but the 12z Euro ensembles show a very cold pattern at 500.  Source region might be lacking at first, but if that holds....it could tap some really cold air from over the top.  We have seen this several times during the past few years as a head fake, so I am holding my fire.  However, I like what I see from this far out.  

That is a cold look Fountain!

[nrgjeff]

Cold returning after the mild interlude next week really would not surprise me. See if we can book a BN average for November.

ECMWF monthlies came out today. First look, I grunted winter canceled after December. Chart is seasonable Dec.

January and February composites are mild. However splitting into clusters, it's actually fairly close to 50/50 each month. There's a warm cluster; and both months, there's a pretty good cold cluster. In other words it's TBD.

If November can end cold going into December, it could hold for a few more weeks until the first January thaw. Though not every year, a cold November is a bullish correlation for winter.

If we come back Monday to a mild forecast and November crap-out, I'll sign off until March, lol!

[Mr. Kevin]

11 minutes ago, nrgjeff said:

Cold returning after the mild interlude next week really would not surprise me. See if we can book a BN average for November.

ECMWF monthlies came out today. First look, I grunted winter canceled after December. Chart is seasonable Dec.

January and February composites are mild. However splitting into clusters, it's actually fairly close to 50/50 each month. There's a warm cluster; and both months, there's a pretty good cold cluster. In other words it's TBD.

If November can end cold going into December, it could hold for a few more weeks until the first January thaw. Though not every year, a cold November is a bullish correlation for winter.

If we come back Monday to a mild forecast and November crap-out, I'll sign off until March, lol!

Jeff, I will take your word on it lol. I'm thinking alot warmer winter this winter, even though last winter wasnt cold, outside of a week to two weeks in February. I just want to see one winter event in my area. 

[PowellVolz]

I would take another 4-6” on Christmas Eve.

Que the… “that’s what she said” joke


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[Carvers Gap]

17 hours ago, Carvers Gap said:

Way, way out there but the 12z Euro ensembles show a very cold pattern at 500.  Source region might be lacking at first, but if that holds....it could tap some really cold air from over the top.  We have seen this several times during the past few years as a head fake, so I am holding my fire.  However, I like what I see from this far out.  

That is a cold look Fountain!

LOL.  I have no idea what a cold look Fountain is(maybe spellcheck derived it from "forecast"???)....Probably should have said that is a cold portrayal by that model since model output is technically not a forecast.  

[Daniel Boone]

2 hours ago, Carvers Gap said:

LOL.  I have no idea what a cold look Fountain is(maybe spellcheck derived it from "forecast"???)....Probably should have said that is a cold portrayal by that model since model output is technically not a forecast.  

Them cold look fountains are the one's that just look like they'd just have to have cold water flowing out of them. Lol

[nrgjeff]

I'll be happy to meet you half way. Warmer than normal OK. Can we go AN severe weather too?

On 11/5/2021 at 4:57 PM, Mr. Kevin said:

Jeff, I will take your word on it lol. I'm thinking alot warmer winter this winter, even though last winter wasnt cold, outside of a week to two weeks in February. I just want to see one winter event in my area. 

Anyway weekend forecasts have turned colder in the 6-15 day with excellent agreement and some sub-seasonal support. Models themselves are nearly unanimous in the 6-10 day. The tight clusters in the 11-15 day are unusual, and welcome to cold fans.

Back to the sub-seasonal. Yukon ridges like to be stubborn this time of year, once re-established. Big MJO pulse about to come out of the Indian Ocean into the West Pacific. That's a cold 6-15 day signal!

If this verifies, November will average colder than normal. Correlation with balance of winter is good, but no promise. I would favor that cold balance early. First January thaw could end the party, but I'm getting ahead of reality. November is the primary objective. 

[jaxjagman]

 

[Mr. Kevin]

15 minutes ago, jaxjagman said:

 

Is that a cold weather signal jax? I'm not too versed in mjo stuff because sometimes the mjo has a mind of its own from everything else lol

[jaxjagman]

1 hour ago, Mr. Kevin said:

Is that a cold weather signal jax? I'm not too versed in mjo stuff because sometimes the mjo has a mind of its own from everything else lol

Its cold signals right now

[nrgjeff]

However there's a disturbance in the Force. Invest in the Indian Ocean could disrupt the MJO cycle. That'd cause the cold to hang up in the Midwest above a suppressed SER.

Otherwise the moderate La Nina should promote cold intrusions into the South eventually. If the MJO pulse survives the Indian Ocean shenanigans, the cold may be sooner rather than later.

Finally, a persistent -WPO is forecast. In past La Ninas with -WPO November cold did kind of hang up; however, Decembers were very cold into the Southeast. Something to watch.

[Mr. Kevin]

10 hours ago, nrgjeff said:

However there's a disturbance in the Force. Invest in the Indian Ocean could disrupt the MJO cycle. That'd cause the cold to hang up in the Midwest above a suppressed SER.

Otherwise the moderate La Nina should promote cold intrusions into the South eventually. If the MJO pulse survives the Indian Ocean shenanigans, the cold may be sooner rather than later.

Finally, a persistent -WPO is forecast. In past La Ninas with -WPO November cold did kind of hang up; however, Decembers were very cold into the Southeast. Something to watch.

Jeff, I thought the mjo was supposed to be going into 4 5 and 6 but maybe not now. Or delayed but not denied? I'm not sure. Hopefully the mjo will be moving soon

[Carvers Gap]

Leaning towards an ensemble head fake this AM regarding the return to cold after this weekend's amplification.  Lots of modeling(too lazy to name them all) are beginning to show BN heights over Alaska with fading BN heights here.  BN heights over Alaska generally teleconnect to a warm SE.  The Euro Weeklies eventually re-drop the hammer during December in regards to cold here.  Message today....cold this weekend, more moderation than was shown last week both in terms of warmer temps and duration, and still cold for the middle part of December.  Again, this is shoulder season so things will be all over the place.  Jeff's comments above pretty much explain what is driving the change.  The IO has been an absolute thorn for several years...I don't see this winter being any different.  Huge grains of salt though.  Models probably are not done bouncing around.  November can be an incredibly difficult month to model as cold/warm pools(new cold pools/diminishing warmth) are moving thousands of miles from their summer latitudinal norms.  Wavelengths are changing.   This is dice stuff.  At least this time, we kind of know that really cold looks past d8 often verify -----but just not in the place where originally modeled.  

[nrgjeff]

Looks like SER all winter. Just kidding! Joe Bastardi mentions 1989 and 2000 Decembers. He has not been right about anything in years.

Yeah November looks really choppy as Carvers writes just above. I concur. 

That pattern with Bering Sea ridging allows AK to go BN heights November, mild here. However past La Nina years that pattern November have evolved into a colder Southeast US solution by December. Just not Joe B cold, lol!

[Met1985]

4 hours ago, nrgjeff said:

Looks like SER all winter. Just kidding! Joe Bastardi mentions 1989 and 2000 Decembers. He has not been right about anything in years.

Yeah November looks really choppy as Carvers writes just above. I concur. 

That pattern with Bering Sea ridging allows AK to go BN heights November, mild here. However past La Nina years that pattern November have evolved into a colder Southeast US solution by December. Just not Joe B cold, lol!

Yeah im hoping November sets the pattern going into winter.  I wouldn't mind choppy as long as we get chances. 

[PowellVolz]

Yeah im hoping November sets the pattern going into winter.  I wouldn't mind choppy as long as we get chances. 

Are you in a good location for NW flow events?


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[Met1985]

1 hour ago, PowellVolz said:

Are you in a good location for NW flow events?


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Oh yeah. Im facing NW on the TN/NC border. 

[Mr. Kevin]

10 hours ago, nrgjeff said:

Looks like SER all winter. Just kidding! Joe Bastardi mentions 1989 and 2000 Decembers. He has not been right about anything in years.

Yeah November looks really choppy as Carvers writes just above. I concur. 

That pattern with Bering Sea ridging allows AK to go BN heights November, mild here. However past La Nina years that pattern November have evolved into a colder Southeast US solution by December. Just not Joe B cold, lol!

Jeff, I think maybe the mjo isnt moving or alot slower than anticipated. Hopefully at some point this late fall or winter we can have one winter storm. Its always difficult in the south even in the best of patterns in 

[Holston_River_Rambler]

Euro and GFS gave us a nice thanksgiving week present overnight.

0z Euro

 

6z GFS:

 

At this much of a time remove, probably not a lot to get excited about, but there were a couple ensemble hits later in Thanksgiving week. 

 

MJO convection looks pretty dispersed to me:

 

Looks like the RMMs have it in the COD.  I could be wishcasting, but I don't think I remember seeing that much convection in the equatorial region of the N. hemisphere that far east, on the Himawari 8 satellite. 

[Daniel Boone]

12z GFS went totally into the crapper !

[nrgjeff]

The MJO indeed stalled last week per looking at the historical index and also satellite movies.

On 11/10/2021 at 7:51 PM, Mr. Kevin said:

Jeff, I think maybe the mjo isnt moving or alot slower than anticipated. Hopefully at some point this late fall or winter we can have one winter storm. Its always difficult in the south even in the best of patterns in 

We have another Invest in the IO which could throw yet another wrench. However - key difference - is that convection is already in the West Pac. No surprise models have turned colder for the 6-15 day.

[Carvers Gap]

Man, that is a monster block over Greenland showing up on both the 18z GEFS and 12z EPS for the end of November - monster.  Euro Weeklies have it as well.  Weeklies are back to a cold look until late December when winter shifts back out West.  Huge grains of salt, folks.  I do think the blocking signal has merit.  The Euro picked up on this last week.  It has been really windy during the past week.  I usually notice this during the fall when their are nearly opposite air masses near each other - Captain Obvious I know.  That said, this means that we are not likely going to be in a zonal patter for long periods of time.  If we want cold, we don't want universally meh air masses UMAM.  My term.

[Mr. Kevin]

46 minutes ago, Carvers Gap said:

Man, that is a monster block over Greenland showing up on both the 18z GEFS and 12z EPS for the end of November - monster.  Euro Weeklies have it as well.  Weeklies are back to a cold look until late December when winter shifts back out West.  Huge grains of salt, folks.  I do think the blocking signal has merit.  The Euro picked up on this last week.  It has been really windy during the past week.  I usually notice this during the fall when their are nearly opposite air masses near each other - Captain Obvious I know.  That said, this means that we are not likely going to be in a zonal patter for long periods of time.  If we want cold, we don't want universally meh air masses UMAM.  My term.

The issue is the trough in GOA. I guess we should expect it in a -pdo. Hard to get real cold with that. The Greenland block is nice, but definitely too early in season for winter storms of any significance outside the higher elevations. End of eps had a ridge over Alaska but its 15 days out

[Carvers Gap]

9 hours ago, Mr. Kevin said:

The issue is the trough in GOA. I guess we should expect it in a -pdo. Hard to get real cold with that. The Greenland block is nice, but definitely too early in season for winter storms of any significance outside the higher elevations. End of eps had a ridge over Alaska but its 15 days out

Oddly, in NE TN at lower elevations we have had multiple early season snows during the past decade.  I actually consider early season snows bad for winter.  Seems like what is required for early season snows is a very active, late hurricane season and early season cold.  That combo has a tendency to cause problems with the winter pattern IMHO.  So, I am perfectly happen with no early season snows.

Modeling has had conflicting teleconnections for weeks.  I think that is partly due to it being shoulder season.  Things are in transition, and signals are often in conflict with each other.  As noted earlier in the thread, modeling for a couple of years has had a bad bias between d10-16 of portraying cold shots into the EC, only to have them verify more westward.  

I do think we are on track for an early start to winter.  My biggest question is once the inevitable thaw hits during late December, does it come back?  Some Nina years this happens, and for some it leaves and is gone.  Time will tell.

Again, HUGE grains of salt as mentioned earlier...

[tnweathernut]

4 hours ago, Carvers Gap said:

Oddly, in NE TN at lower elevations we have had multiple early season snows during the past decade.  I actually consider early season snows bad for winter.  Seems like what is required for early season snows is a very active, late hurricane season and early season cold.  That combo has a tendency to cause problems with the winter pattern IMHO.  So, I am perfectly happen with no early season snows.

Modeling has had conflicting teleconnections for weeks.  I think that is partly due to it being shoulder season.  Things are in transition, and signals are often in conflict with each other.  As noted earlier in the thread, modeling for a couple of years has had a bad bias between d10-16 of portraying cold shots into the EC, only to have them verify more westward.  

I do think we are on track for an early start to winter.  My biggest question is once the inevitable thaw hits during late December, does it come back?  Some Nina years this happens, and for some it leaves and is gone.  Time will tell.

Again, HUGE grains of salt as mentioned earlier...

Agree, but I reserve this designation for October to early November snows, not late November and early December.  Glad to be looking and trying to find winter again.  Hope everyone has been doing well.

[Carvers Gap]

This -NAO shown on the EPS(for the past several days) could be a tough feature to move if it actually forms at that intensity.  Something to watch.  Models may be playing a bit of catch-up in the LR.  Greenland blocks are notoriously stubborn features and models are often erroneous in breaking them down too quickly.  

[Mr. Kevin]

6 hours ago, Carvers Gap said:

This -NAO shown on the EPS(for the past several days) could be a tough feature to move if it actually forms at that intensity.  Something to watch.  Models may be playing a bit of catch-up in the LR.  Greenland blocks are notoriously stubborn features and models are often erroneous in breaking them down too quickly.  

I feel like when it breaks down, we are screwed lol. Pacific is in bad shape. People mention November 2010. I think the Pacific was in better shape than currently. Imo, if we donr get any winter storms in December, that may be it especially with everyone going front loaded winter 

[tnweathernut]

7 hours ago, Mr. Kevin said:

I feel like when it breaks down, we are screwed lol. Pacific is in bad shape. People mention November 2010. I think the Pacific was in better shape than currently. Imo, if we donr get any winter storms in December, that may be it especially with everyone going front loaded winter 

Generally, in the winter………. We are screwed. lol

At our latitude we typically look for the 2-3 day period in time where it all comes together just right.  Then when snow is probable, we over analyze each model run, looking for the level of the atmosphere which will screw us by being +1 and throwing ZR while those just north of us see most of the snow.   Such is life in the south.

I say all that to say this.  There’s always something that can screw us, but even bad winters will usually find a way to throw a bone or two.  Just have to get lucky when it does.