Tennessee Valley 2019 Fall Speculation/Forecasting

[TellicoWx]

May not amount much for us, but one thing I have noticed since yesterday with this system, is the mesoscale models have way underperformed on guidance up until 18-24 hrs out. Yesterday it was the upper Ohio valley (great read in their sub forum of how the nam was very late joining the globals, specifically the Euro, on guidance). Tonight there is a large uptick over Western KY/AR MO boothill once in that 18-24 timeframe. Seems like the mesos are playing catch up with the speed of changeover and moisture being squeezed out. May mean nothing here, but interested in watching how it plays out. 

[ShawnEastTN]

May not amount much for us, but one thing I have noticed since yesterday with this system, is the mesoscale models have way underperformed on guidance up until 18-24 hrs out. Yesterday it was the upper Ohio valley (great read in their sub forum of how the nam was very late joining the globals, specifically the Euro, on guidance). Tonight there is a large uptick over Western KY/AR MO boothill once in that 18-24 timeframe. Seems like the mesos are playing catch up with the speed of changeover and moisture being squeezed out. May mean nothing here, but interested in watching how it plays out. 

Good catch, I generally try to temper enthusiasm for anafrontal snow, we all know the vast majority of these don't perform at all for us, but there are a couple things going for the forum that help a bit in my opinion, first the strength of the cold and that massive massive High behind the front, and second the time of the day being after dark we don't have the sun to work against us. Think among anafrontal potentials over the years this one has among the highest odds to over perform.  

Sent from my SM-G965U using Tapatalk

 

 

 

 

 

[TellicoWx]

Just one example across W KY/Boothill area from one of the HRW models (noticeable increases on all the HRW, NAM, so on):

[jaxjagman]

13 minutes ago, TellicoWx said:

May not amount much for us, but one thing I have noticed since yesterday with this system, is the mesoscale models have way underperformed on guidance up until 18-24 hrs out. Yesterday it was the upper Ohio valley (great read in their sub forum of how the nam was very late joining the globals, specifically the Euro, on guidance). Tonight there is a large uptick over Western KY/AR MO boothill once in that 18-24 timeframe. Seems like the mesos are playing catch up with the speed of changeover and moisture being squeezed out. May mean nothing here, but interested in watching how it plays out. 

NAM never does well with mesoscales outside 24 hrs,it's why no one uses it in severe weather

[Snowy Hibbo]

G’day everyone.

I would just like to present my final seasonal outlook for the North America, which includes driver discussion and analysis for patterns that run downstream to the Tennessee Valley. And it’s looking pretty cold and snowy down your way IMO

https://longrangesnowcenter.net/2019/11/10/north-american-winter-outlook-2019-20/

 

And it’s probably why the region is getting forecasts of snowfall this early.

- Snowy Hibbo  

 

 

[jaxjagman]

13 minutes ago, Snowy Hibbo said:

G’day everyone.

I would just like to present my final seasonal outlook for the North America, which includes driver discussion and analysis for patterns that run downstream to the Tennessee Valley. And it’s looking pretty cold and snowy down your way IMO

https://longrangesnowcenter.net/2019/11/10/north-american-winter-outlook-2019-20/

 

And it’s probably why the region is getting forecasts of snowfall this early.

- Snowy Hibbo  

 

 

Good luck,still don't know why everyone says this is  Modoki when the warmer SST'S in the subsurface are east of the IDL

[Snowy Hibbo]

4 minutes ago, jaxjagman said:

Good luck,still don't know why everyone says this is  Modoki when the warmer SST'S are east of the IDL

Thanks  
You could argue a lot things about ENSO this winter. Neutral. Weak Modoki (which is what I see). It’s still quite Nina-esque in the extratropics. And some people are calling it a “solid Nino”. But honestly and I try and convey this in the outlook with the use of other drivers, it’s not awfully important the exact definitions of the ENSO at an oceanic level.

[jaxjagman]

11 minutes ago, Snowy Hibbo said:

Thanks  
You could argue a lot things about ENSO this winter. Neutral. Weak Modoki (which is what I see). It’s still quite Nina-esque in the extratropics. And some people are calling it a “solid Nino”. But honestly and I try and convey this in the outlook with the use of other drivers, it’s not awfully important the exact definitions of the ENSO at an oceanic level.

Well thanks for droppping by and your insight.I'm not familiar with your area in Australia but you guys on fire from the IOD ?Seen some sad vids from your parts

 

[Snowy Hibbo]

Just now, jaxjagman said:

Well thanks for droppping by and your insight.I'm not familiar with your area in Australia but you guys on fire from the IOD ?

 

Yes unfortunately. I guess it’s probably more interesting for me to look at your snowfall chances, than the hot summer ahead for myself  

[jaxjagman]

6 minutes ago, Snowy Hibbo said:

Yes unfortunately. I guess it’s probably more interesting for me to look at your snowfall chances, than the hot summer ahead for myself  

Well we have the snow dome here..lol,,Been lasting for years

[jaxjagman]

Euro bumped up and shows a change over around 9 or 10 tomorrow night for us,with almost 2" ,more in the east,only a dusting in the SW Valley more for you guys in the east,we'll see

 

ECMWF Deterministic FORECAST FOR: BNA    LAT=  36.12 LON=  -86.68 ELE=   591

                                            00Z NOV11
                 2 M     2 M     2 M     SFC     SFC     3/6    FROZN   TOTAL
                 MXT     MNT     TMP     DEW     WIND    HR      PCP    CLOUD
                 (F)     (F)     (F)     (F)    (KTS)   (IN)    (IN)    (PCT)
MON 00Z 11-NOV                  53.8    42.1    19007                     81    
MON 03Z 11-NOV                  51.2    41.5    19006                    100    
MON 06Z 11-NOV  54.1    48.7    48.6    41.1    19006                     97    
MON 09Z 11-NOV                  45.9    40.9    20005   0.00    0.00      83    
MON 12Z 11-NOV  48.6    44.7    44.7    40.9    19006   0.00    0.00       2    
MON 15Z 11-NOV                  55.6    43.8    20007   0.00    0.00      57    
MON 18Z 11-NOV  62.7    44.5    62.7    46.3    22007   0.00    0.00      98    
MON 21Z 11-NOV                  58.0    50.9    24003   0.03    0.00     100    
TUE 00Z 12-NOV  62.8    48.6    48.0    47.2    33010   0.09    0.00     100    
TUE 03Z 12-NOV                  36.1    35.6    35011   0.13    0.01     100    
TUE 06Z 12-NOV  48.1    30.6    30.4    27.4    34012   0.30    0.14     100    
TUE 09Z 12-NOV                  27.1    18.9    35013   0.03    0.03      83    
TUE 12Z 12-NOV  30.4    22.8    22.6    11.6    35011   0.03    0.03       0    
TUE 15Z 12-NOV                  24.1     7.9    35011   0.00    0.00       0    

[jaxjagman]

Would actually put a nozzle in Jeff where he says it cant snow..lol

ECMWF Deterministic FORECAST FOR: CHA    LAT=  35.03 LON=  -85.20 ELE=   689

                                            00Z NOV11
                 2 M     2 M     2 M     SFC     SFC     3/6    FROZN   TOTAL
                 MXT     MNT     TMP     DEW     WIND    HR      PCP    CLOUD
                 (F)     (F)     (F)     (F)    (KTS)   (IN)    (IN)    (PCT)
MON 00Z 11-NOV                  51.1    40.6    20005                     58    
MON 03Z 11-NOV                  49.0    39.2    20005                    100    
MON 06Z 11-NOV  52.0    46.9    47.4    38.9    19005                     98    
MON 09Z 11-NOV                  45.5    39.6    20004   0.00    0.00      88    
MON 12Z 11-NOV  47.6    42.8    42.8    39.2    18004   0.00    0.00       4    
MON 15Z 11-NOV                  55.4    43.0    19003   0.00    0.00       2    
MON 18Z 11-NOV  63.1    42.6    63.2    44.4    22006   0.00    0.00      89    
MON 21Z 11-NOV                  61.3    45.8    22004   0.00    0.00      95    
TUE 00Z 12-NOV  63.3    55.3    55.1    46.9    20003   0.01    0.00     100    
TUE 03Z 12-NOV                  54.1    49.9    23004   0.01    0.00     100    
TUE 06Z 12-NOV  55.1    46.6    45.6    45.4    33009   0.10    0.00     100    
TUE 09Z 12-NOV                  36.4    36.2    35010   0.17    0.00     100    
TUE 12Z 12-NOV  45.6    32.1    31.9    29.4    35011   0.42    0.15     100    
TUE 15Z 12-NOV                  30.8    21.8    35012   0.01    0.01      99    
TUE 18Z 12-NOV  35.2    30.4    35.3    17.9    35010   0.01    0.01      49    

[jaxjagman]

Nice hit for guys east tho,hope someone scores

 

ECMWF Deterministic FORECAST FOR: TYS    LAT=  35.82 LON=  -83.98 ELE=   981

                                            00Z NOV11
                 2 M     2 M     2 M     SFC     SFC     3/6    FROZN   TOTAL
                 MXT     MNT     TMP     DEW     WIND    HR      PCP    CLOUD
                 (F)     (F)     (F)     (F)    (KTS)   (IN)    (IN)    (PCT)
MON 00Z 11-NOV                  51.0    39.9    22004                      0    
MON 03Z 11-NOV                  48.3    38.0    20005                     96    
MON 06Z 11-NOV  52.0    46.8    46.8    38.0    20004                    100    
MON 09Z 11-NOV                  44.4    38.4    20003   0.00    0.00      95    
MON 12Z 11-NOV  46.8    43.1    43.2    39.1    19003   0.00    0.00      64    
MON 15Z 11-NOV                  54.7    41.8    23005   0.00    0.00      23    
MON 18Z 11-NOV  61.2    43.0    61.3    42.5    22007   0.00    0.00      49    
MON 21Z 11-NOV                  59.0    44.0    24006   0.00    0.00      88    
TUE 00Z 12-NOV  62.3    54.4    54.3    45.0    20006   0.02    0.00      98    
TUE 03Z 12-NOV                  52.7    46.2    22006   0.01    0.00     100    
TUE 06Z 12-NOV  54.3    45.9    45.6    45.2    34008   0.10    0.00     100    
TUE 09Z 12-NOV                  35.6    34.7    36008   0.20    0.01     100    
TUE 12Z 12-NOV  45.6    31.5    31.4    29.0    36008   0.47    0.27     100    
TUE 15Z 12-NOV                  29.8    23.4    36009   0.06    0.06     100  

 

ECMWF Deterministic FORECAST FOR: TRI    LAT=  36.47 LON=  -82.40 ELE=  1519

                                            00Z NOV11
                 2 M     2 M     2 M     SFC     SFC     3/6    FROZN   TOTAL
                 MXT     MNT     TMP     DEW     WIND    HR      PCP    CLOUD
                 (F)     (F)     (F)     (F)    (KTS)   (IN)    (IN)    (PCT)
MON 00Z 11-NOV                  46.6    38.0    20004                      0    
MON 03Z 11-NOV                  44.6    38.3    17003                      0    
MON 06Z 11-NOV  48.2    42.2    44.2    37.2    30001                    100    
MON 09Z 11-NOV                  40.2    36.2    14003   0.00    0.00      93    
MON 12Z 11-NOV  46.0    37.9    38.4    35.3    18002   0.00    0.00      96    
MON 15Z 11-NOV                  53.5    40.2    24003   0.00    0.00      22    
MON 18Z 11-NOV  60.1    38.1    60.2    40.3    24006   0.00    0.00      66    
MON 21Z 11-NOV                  58.6    42.6    25005   0.00    0.00      91    
TUE 00Z 12-NOV  61.0    52.3    52.1    42.2    23005   0.00    0.00      86    
TUE 03Z 12-NOV                  49.4    44.7    22005   0.02    0.00      99    
TUE 06Z 12-NOV  52.2    47.6    47.5    46.3    23004   0.05    0.00     100    
TUE 09Z 12-NOV                  38.8    38.6    33006   0.18    0.00     100    
TUE 12Z 12-NOV  47.7    32.3    32.2    30.2    32007   0.35    0.13     100    
TUE 15Z 12-NOV                  30.2    23.1    33008   0.12    0.12     100    
TUE 18Z 12-NOV  32.2    29.6    30.7    17.9    33009   0.12    0.12      94  

[jaxjagman]

Gonna depend for everyone seemingly how fast the cold air sweepn in looking at MEM

 

ECMWF Deterministic FORECAST FOR: MEM    LAT=  35.05 LON=  -90.00 ELE=   285

                                            00Z NOV11
                 2 M     2 M     2 M     SFC     SFC     3/6    FROZN   TOTAL
                 MXT     MNT     TMP     DEW     WIND    HR      PCP    CLOUD
                 (F)     (F)     (F)     (F)    (KTS)   (IN)    (IN)    (PCT)
MON 00Z 11-NOV                  55.6    45.1    18007                     97    
MON 03Z 11-NOV                  53.5    41.7    18008                     84    
MON 06Z 11-NOV  55.6    51.1    51.0    41.8    19007                     89    
MON 09Z 11-NOV                  48.6    43.1    19006   0.00    0.00       5    
MON 12Z 11-NOV  51.0    47.7    48.0    43.7    19007   0.00    0.00      42    
MON 15Z 11-NOV                  56.6    47.8    19008   0.04    0.00      91    
MON 18Z 11-NOV  58.6    48.0    57.9    52.1    22005   0.12    0.00     100    
MON 21Z 11-NOV                  53.6    51.6    34010   0.26    0.00     100    
TUE 00Z 12-NOV  57.9    38.4    37.9    35.2    36017   0.45    0.00     100    
TUE 03Z 12-NOV                  32.0    28.9    00016   0.16    0.01     100    
TUE 06Z 12-NOV  37.9    29.8    29.7    20.1    36015   0.17    0.02      97    
TUE 09Z 12-NOV                  25.2     9.1    36015   0.00    0.00      43    

 

 

[jaxjagman]

See what happens anyways,bout OBS time shortly

[McMinnWx]

So, Weather Channel just said 1-3 for McMinn County? 

[PowellVolz]

So, Weather Channel just said 1-3 for McMinn County? 

Are you asking or did you hear that?


.

[McMinnWx]

6 minutes ago, PowellVolz said:

Are you asking or did you hear that?

 

They were discussing it this morning on TWC.  The graphic had us in the 1-3 range.  WRCB said 1.3  

[Carvers Gap]

That is not a pretty picture on the 12z or 18z GEFS in the d10-15 - Well above normal temps being portrayed with an eastern ridge connecting to a -NAO.  When have we seen that before?  September.  Thankfully, the 12z EPS is not on board with that business.  On a positive note, there is evidence on the EPS that a -NAO is trying to develop.  If true, just throw modeling out the window right now.  High latitude blocking wrecks LR models at times...just too many plates to juggle.  I was feeling pretty good about December until I saw the GEFS.  The Euro Weeklies(I don't even look at surface temps on it anymore because they are always warm after week 2) have a decent 500 pattern through mid-December before their predictable global torch for weeks 4-6. Weeks 2-4 looks overall seasonable with not a ton of amplification.   I have recently had a slight lean towards a BN first half of December...but the GEFS has me spooked.  Maybe it shouldn't, but it has been ahead of the EPS on pattern changes lately.  The GEFS is a bit of an outlier...but it has led the way for about six weeks.  So, it can't be discounted just yet.   The GEFS is a total flip of the pattern beginning at day 10.  Definitely some things in the LR that still have to be worked out and have repercussions regarding the first month of winter.

[Daniel Boone]

6 minutes ago, Carvers Gap said:

That is not a pretty picture on the 12z or 18z GEFS in the d10-15 - Well above normal temps being portrayed with an eastern ridge connecting to a -NAO.  When have we seen that before?  September.  Thankfully, the 12z EPS is not on board with that business.  On a positive note, there is evidence on the EPS that a -NAO is trying to develop.  If true, just throw modeling out the window right now.  High latitude blocking wrecks LR models at times...just too many plates to juggle.  I was feeling pretty good about December until I saw the GEFS.  The Euro Weeklies(I don't even look at surface temps on it anymore because they are always warm after week 2) have a decent 500 pattern through mid-December before their predictable global torch for weeks 4-6. Weeks 2-4 looks overall seasonable with not a ton of amplification.   I have recently had a slight lean towards a BN first half of December...but the GEFS has me spooked.  Maybe it shouldn't, but it has been ahead of the EPS on pattern changes lately.  The GEFS is a bit of an outlier...but it has led the way for about six weeks.  So, it can't be discounted just yet.   The GEFS is a total flip of the pattern beginning at day 10.  Definitely some things in the LR that still have to be worked out and have repercussions regarding the first month of winter.

That September setup of a -Nao hooking up with a SE Ridge is a somewhat typical setup in summer months but, not Winter. Has happened  but, rare. So, hopefully the law of averages works in this case. 

[AMZ8990]

12 minutes ago, Carvers Gap said:

That is not a pretty picture on the 12z or 18z GEFS in the d10-15 - Well above normal temps being portrayed with an eastern ridge connecting to a -NAO.  When have we seen that before?  September.  Thankfully, the 12z EPS is not on board with that business.  On a positive note, there is evidence on the EPS that a -NAO is trying to develop.  If true, just throw modeling out the window right now.  High latitude blocking wrecks LR models at times...just too many plates to juggle.  I was feeling pretty good about December until I saw the GEFS.  The Euro Weeklies(I don't even look at surface temps on it anymore because they are always warm after week 2) have a decent 500 pattern through mid-December before their predictable global torch for weeks 4-6. Weeks 2-4 looks overall seasonable with not a ton of amplification.   I have recently had a slight lean towards a BN first half of December...but the GEFS has me spooked.  Maybe it shouldn't, but it has been ahead of the EPS on pattern changes lately.  The GEFS is a bit of an outlier...but it has led the way for about six weeks.  So, it can't be discounted just yet.   The GEFS is a total flip of the pattern beginning at day 10.  Definitely some things in the LR that still have to be worked out and have repercussions regarding the first month of winter.

 MJO possibly could be at or in a colder phase towards the end of the November.  May get December started off right and chilly if it pans out.  

[John1122]

For later winter purposes, I'm not terribly against the first two weeks of December being seasonable or slightly AN. 

[Carvers Gap]

5 minutes ago, John1122 said:

For later winter purposes, I'm not terribly against the first two weeks of December being seasonable or slightly AN. 

I agree.  We don't want what the Euro Weeklies were cooking up though...but they have been awful in the 4-6 week range(for the past year or so...they used to have some skill before last winter).  What the GEFS is showing took several weeks to dislodge in September, and only seasonal wave lengths really disrupted it.  That said....it is the GEFS and it does not have support yet.  It also makes sense to have some sort of moderation after the well BN temps that we have been having.  And true, many great winters never really got going until January.  Last year has spooked me as well along with isotherm's forecast.  LOL.  

[AMZ8990]

15 minutes ago, Carvers Gap said:

I agree.  We don't want what the Euro Weeklies were cooking up though...but they have been awful in the 4-6 week range(for the past year or so...they used to have some skill before last winter).  What the GEFS is showing took several weeks to dislodge in September, and only seasonal wave lengths really disrupted it.  That said....it is the GEFS and it does not have support yet.  It also makes sense to have some sort of moderation after the well BN temps that we have been having.  And true, many great winters never really got going until January.  Last year has spooked me as well along with isotherm's forecast.  LOL.  

What was December like in that 54 or 55 analog you’ve been comparing with??

[John1122]

10 minutes ago, AMZ8990 said:

What was December like in that 54 or 55 analog you’ve been comparing with??

December 1954 here was cold for the 1st 20 days of the month and AN the last 10 days. It snowed on 7 different days, the biggest the 18th and 19th with 3.75 inches total for the month. 

[Carvers Gap]

LOL.  The Weeklies depict almost exactly what John mentioned in terms of temps.  No idea what its snow mean for that time frame was.  1954 lives on...

1954 began almost as a joke, because here at TRI we couldn't break those max temp records during September, but crushing all other years.  For September, 1954 holds eight record highs.  2019 holds eight record highs.  For October, 1954 holds four records highs.  2019 holds for record highs.  And what is uncanny is that some of the warm spells came within a week of each other on the calendar.  Then November turned cold during both months with snow reported in measurable amounts.   The current cooler water off of SA may be acting as a bit of a weak Nina signal and that may be allowing for some mirroring of the two years.  Still just sort of weird at this point.  Not sure the two years are a great match in terms of SSTs...but their Septembers, Octobers, Novembers, and maybe even Decembers(???) are super similar.  All of that said, sometimes things that appear to have good correlations...have no relationship whatsoever.  There are actually some pretty hilarious (and false) connections that statistics bring together at times.  In this case, maybe the Nina ENSO in the eastern Pacific is something to think about.  Also, it seems like the weather patterns recently have been similar to the early and mid 50s analogs.  So, there might be something to that.  Anyway, it is now just kind of fun to see just how far we can take an "iffy" analog.  

[John1122]

The 1954 December warmth blend into about 10 days of Jan 1955. Mid month there was a 6 inch snow event. Last 10 days of Jan were well BN, snow showery, some trace events,  some quarter to .5 inch events and a 1 inch event. Low for the month was 0 on Jan 29th. February was up and down the first 10 days, some rain, some light snow. Mid month there was a 3.75 inch snow event on the 11th, and a -5 low on the 13th with 1.25 inches of snow on the 14th. March of 1955 was a roller coaster with big warm ups and a few cold shots including a frigid last week of the month, snowed 5 times but trace amounts. March ended up normal temp wise for the month.  April was full blown warm spring.  

 

Nov 2.5 inches -5.5 bn temps

December 3.75 inches -4

January 8.5 inches -2.5

February 5.5 inches. -1

March 5x trace amounts.  N

So roughly 19 inches here that winter, Nov-Feb were all BN with Nov being the coldest month relative to normal. 

[Carvers Gap]

2 hours ago, Daniel Boone said:

That September setup of a -Nao hooking up with a SE Ridge is a somewhat typical setup in summer months but, not Winter. Has happened  but, rare. So, hopefully the law of averages works in this case. 

Yeah, I agree.  Would be super surprised to see that hold in place for very long during winter.  Although it seems like during a recent winter the WAR retrograded into eastern NA and did something similar for a few weeks and actually triggered an SSW.  Yep, that occurred during one or both of the last two SSWs.  So for the ah-ha moment of the evening, that look actually has proceeded the last two strat warming events - I think...definitely one.  Your comment actually jogged my memory on that.  It is indeed rare...but now I remember where I have seen it before.  So, it will be interesting to see if an early winter SSW occurs.  Maybe that is an example of a tropospheric planetary wave that potentially could transport a ton of warm air into the high latitudes.  That could potentially displace the PV.  At one time, I had made a mental note to remember that look....it is probably buried in one of the threads where we talked about SSWs.  

Below is the eastern NA ridge connecting to the -NAO.  The EPS does not have this...trough is in the East.  Anyway, I am not using a 384 hour map for any other purpose than to show what I was talking about.  Only 64 more GFS runs before we reach that time frame!  Anyway, that look is super similar to the WAR that hooked up with the -NAO that preceded one or both of the last strat warming events.  Interesting.  

[Carvers Gap]

Also, looks like the QBO for October finished at 7.27 which is down from 8.25.  So the QBO is still trending down.   We want to see a sharper drop I think.  Would not be surprised to see it negative by January.  When glancing at previous downward trajectories, it seems like it will hover between 5-10 and then just drop(on its descending part of the cycle).

[Mr. Kevin]

12 minutes ago, Carvers Gap said:

Yeah, I agree.  Would be super surprised to see that hold in place for very long during winter.  Although it seems like during a recent winter the WAR retrograded into eastern NA and did something similar for a few weeks and actually triggered an SSW.  Yep, that occurred during one or both of the last two SSWs.  So for the ah-ha moment of the evening, that look actually has proceeded the last two strat warming events - I think...definitely one.  Your comment actually jogged my memory on that.  It is indeed rare...but now I remember where I have seen it before.  So, it will be interesting to see if an early winter SSW occurs.  Maybe that is an example of a tropospheric planetary wave that potentially could transport a ton of warm air into the high latitudes.  That could potentially displace the PV.  At one time, I had made a mental note to remember that look....it is probably buried in one of the threads where we talked about SSWs.  

Below is the eastern NA ridge connecting to the -NAO.  The EPS does not have this...trough is in the East.  Anyway, I am not using a 384 hour map for any other purpose than to show what I was talking about.  Only 64 more GFS runs before we reach that time frame!  Anyway, that look is super similar to the WAR that hooked up with the -NAO that preceded one or both of the last strat warming events.  Interesting.  

Hi carver. ISOTHERM'S forcast scares me too lol. I dont want him to be right if we have any chance this winter. Why do you think the epo/wpo are going positive? Is it the mjo moving to unfavorable phases? I am still clueless with that.