December/January 2019/20 Winter Speculation Thread

[weathertree4u]

12 minutes ago, Holston_River_Rambler said:

Don't know if I've ever seen two pieces of energy from such different places phase nearly overhead. 

If any of us can get this upper low to pass over head, could be some fun lapse rates and dynamics. 

Yeah, just saw that Nashville already has flood warnings and advisories in addition to the nearly valley wide flood watches, so that atmospheric river isn't promising:

Honestly though, most of my childhood memories of growing up in Nashville were with Winters where it rained and rained and rained; there were those Winters in the late 1970's that were good one or two in the 1980's but after that, man, seems like it is just always warm and wet!

[Holston_River_Rambler]

Pretty good agreement for at least a dusting - inch from the plateau east on the EPS:

for some reason 0z hadn't yet loaded on weathermodels. 

Soon we shall be in SREF range, then the fun will really begin, lol!

[Carvers Gap]

American modeling completely caved to the Euro last night on the MJO.   I still think there are some feedback issues on modeling and that there will be some variability in the LR pattern, at least more than is modeled on ensembles.  However, I can remember plenty of years at UT when I was walking to class in a t-shirt during January and February.  So, non-winters and warm winters do happen at this latitude.  This has every semblance of one of those 1990s winters that were very warm...On the bright side, once every 2-3 years, there were bigs snows and/or bad winters.  Even during warm winters, there were usually time frames where it could snow.  Looks like there might be some sort of pattern shake-up later this month.  Again, that would fit with the duration of this warm pattern that developed during early December.  As I noted in June, if the MJO continues to fire...going to be an ugly pattern setting up shop.  The main way we get out of this is with Atlantic blocking.  On some modeling, one can see another way as well.   The western trough lifts north around January 20th-ish and then sets up shop in a retrograding fashion over the Aleutians.  Cold air bellies under the easter ridge and the pattern changes or relaxes for 7-14 days.  However, though there are signs that indeed the trough will be in the East at the very end of the month...but that itself may be temporary if the MJO cycles back into 4-6 which there are signs of on the EMON.  The Euro model is absolutely schooling the American suite right now.  I do look a the GFS as it can show pattern changes.  However, it really has not been correct very often since late November in the d8-15 range.  I will continue to comment about it, but with the idea that the GFS can't be trusted at all in the LR.  So, not much we can do.  Warmth and likely record warmth of long duration is likely on its way.  We will "hope" for a flip, but with full understanding this is going to take weeks and not days to get out of.  While AN temps do makes sustained snowy patterns very unlikely, it can still snow even in a warm pattern.  I think for this winter the best we can do is hope for a pattern change or relaxation during late January or early February.  Very few despise a warm January more than me, but looks like that is the card we have been dealt barring a major change in modeling which still could happen.  Those flips have happened in the past.  Always important to remember that modeling doesn't control natural factors, but just tries to extrapolate the pattern forward just enough and produce a useful product.  So, it is always possible that things can change, and we will watch for those.  I do think this year we see the November pattern return, but with the understand we could do a January/February 2019 redux.  This is why I hate Nino winters.  They are late arrivals to the party and then sometimes...they just don't arrive.  It would not shock me to see the fall pattern repeat...record warmth followed by a flip.  Indeed, as John noted and the record lows for TRI indicate, 1955 did have cold later in the winter.

As for rain, I think TVA sees it.   They have been sending plenty of water downstream IMBY(I see the Holston multiple times per day) which I usually see prior to rainy time frames.  Cherokee Lake, where my in-laws live, is sitting about its normal low pool for this time of year.  So, looks like there is plenty of room up this way to story the excess rainfall forecast.  Up until this week, urban streams had been running low and clear.  And there is a reason this entire system of dams has been put into place...the TN River Valley is known fro incredible flooding(and droughts).  

 

Happy New Year to everyone.  Wish I had better news, but plenty of time for outdoor stuff.  

[Daniel Boone]

Happy New Year All !

[jaxjagman]

Ugly

 

 

[weathertree4u]

2 minutes ago, jaxjagman said:

Ugly

 

 

I know Nashville Just finished one of the wettest years on record; around here, just down the road from me, literally, there is the start of a rock slide, will call it in to the road department in the am but I would imagine that there would be more of that to come. 

[jaxjagman]

Just now, weathertree4u said:

I know Nashville Just finished one of the wettest years on record; around here, just down the road from me, literally, there is the start of a rock slide, will call it in to the road department in the am but I would imagine that there would be more of that to come. 

You probably live by the rims?We saw this last year i believe if i remember right?Didnt it shut down 65?

 

[weathertree4u]

Just now, jaxjagman said:

You probably live by the rims?We saw this last year i believe if i remember right?Didnt it shut down 65?

 

Almost, we are about a mile from the Higland Rim; makes a huge difference this time of year, often, that 700' - 800' makes the difference between snow and rain. I have too many trees to keep an accurate rain gauge any longer but I am guesstimating from the NWS "water" page, that we had between 70" - 75" last year. I believe it was I-24 but same thing though. Just flat too much rain. 

[Holston_River_Rambler]

EPS still kinda likes this Saturday evening and overnight for plateau east for a dusting to an inch.

Before that, that fire hose is pointed at me in Morgan County. 

Mesoscale models and Euro aim the heaviest band of precip right at Cumberland and Morgan counties.

Will be interesting to see exactly where it sets up. 

 

 

[Holston_River_Rambler]

19 minutes ago, jaxjagman said:

Happy hour GFS agrees with the Euro Control.

12 - 14 inches of rain over the next 13 days. 

[jaxjagman]

2 minutes ago, weathertree4u said:

Almost, we are about a mile from the Higland Rim; makes a huge difference this time of year, often, that 700' - 800' makes the difference between snow and rain. I have too many trees to keep an accurate rain gauge any longer but I am guesstimating from the NWS "water" page, that we had between 70" - 75" last year. I believe it was I-24 but same thing though. Just flat too much rain. 

I thought it was the rims a that blocked it off last year because of the rains but this was in Feb i though,seems to early to have these big rains with record PW's  which seems possible

[jaxjagman]

Just now, Holston_River_Rambler said:

Happy hour GFS agrees with the Euro Control.

12 - 14 inches of rain over the next 13 days. 

Man can you imagine if the MJO were to actually regress back into the Maritime

[weathertree4u]

3 minutes ago, jaxjagman said:

I thought it was the rims a that blocked it off last year because of the rains but this was in Feb i though,seems to early to have these big rains with record PW's  which seems possible

Give you an example of how wet it is, today I dug a twenty foot ditch from a low area in the yard to the creek; when I came back to it after a couple of hours later, it was filled with water. 

[Holston_River_Rambler]

7 minutes ago, jaxjagman said:

Man can you imagine if the MJO were to actually regress back into the Maritime

It could for sure. Masiello was commenting how warm the waters were there now, thanks to the IOD causing the extreme heat in Australia. I wonder if once it gets going, it it will even out do modeled expectations. 

 

[jaxjagman]

Man this should break seemingly   rains,we saw this last Feb,.not Jan

[Carvers Gap]

While were are busying saying a post mortem for a month that hasn't occurred....LOL...enjoy the 18z GFS.  That is one way to make the MJO mute.  Cold overwhelms the pattern.

[jaxjagman]

1 minute ago, Carvers Gap said:

While were are busying saying a post mortem for a month that hasn't occurred....LOL...enjoy the 18z GFS.  That is one way to make the MJO mute.  Cold overwhelms the pattern.

Thats insane,i really dont have a good feeling about this pattern,so rare

[Carvers Gap]

I have quoted JB a couple of times already.  It is very difficult for cold temps to go straight down the spine of the Rockies.  It will take the path of least resistance east or west of the Rockies.  This time it went east.  That much cold is going to spread out, MJO or no MJO.  A huge discharge of cold air can get sent south by a cutter.  

[Carvers Gap]

Just now, jaxjagman said:

Thats insane,i really dont have a good feeling about this pattern,so rare

Yeah, that is the mother load....right in the middle of the warm-up.  I would laugh for days if that actually happened.   Unlikely as that is the GFS at range, but if the cold goes into the front range and then we get a cutter...look out.  The EPS control wasn't far from that look at 12z.

[Carvers Gap]

My gripe for days is that this is an active pattern with an active STJ.  One good storm that cuts into that ridge could change-up the pattern.  I just don't think the northern hemispheric pattern is going to come to a stall for ten days.  Too much energy.  I have been frustrated that modeling doesn't show that active pattern with lots of variability. 

[jaxjagman]

4 minutes ago, Carvers Gap said:

My gripe for days is that this is an active pattern with an active STJ.  One good storm that cuts into that ridge could change-up the pattern.  I just don't think the northern hemispheric pattern is going to come to a stall for ten days.  Too much energy.  I have been frustrated that modeling doesn't show that active pattern with lots of variability. 

As long as you can get a +pna no doubt,we need help from the Aluetians

 

Edit:corrected the PNA

 

 

[Holston_River_Rambler]

I know I'm not saying a Requiem for January snows yet, despite what Mempho wants, but the next 15 days look 2019 February style wet for someone in the valley. Gonna have to get the ark gifs back out. 

Some of the middle and west TN folks already have flood warnings and advisories, in addition to the new watches and there's a new one that just popped up just south of Chattanooga in AL. 

 

[jaxjagman]

2 minutes ago, Holston_River_Rambler said:

I know I'm not saying a Requiem for January snows yet, despite what Mempho wants, but the next 15 days look 2019 February style wet for someone in the valley. Gonna have to get the ark gifs back out. 

Some of the middle and west TN folks already have flood warnings and advisories, in addition to the new watches and there's a new one that just popped up just south of Chattanooga in AL. 

 

Rere you see flood watch regardless into Jan

[Carvers Gap]

So, the 18z GEFS does offer weak support for the operational.  The cold presses under the 500 ridge to the west.  With a run with that much cold in Montana...need to look under the 500 pattern to see if it is pressing.  Not in any way saying I believe the GFS, just glad to see something that shows what "could" happen and what used to happen when cold built in MT.  Get the cold into the front range and get a blizzard to the Lakes...and who knows.  There is a crap ton of cold forecast to be in Canada. 

[Carvers Gap]

Also, if the eastern ridge were to get tall, the base of that ridge will be attacked by the STJ.  Same thing would happen if it was out West.  The thing I suspect is that ensembles are washing out some big storms into the center of the country.  Those storms can fight a ridge in the East.  In September, there was no cold to fight that ridge.  Not so now.  Anyway, going to enjoy my d12-15 cold until the next run and HOPE (which is not a forecast) for a trend to variability.  We are long past due for a crap pattern to actually not verify.

[Carvers Gap]

And again...quick note.  If that much cold is in the front range and you see something slide across at 500, be sure to look at surface temps under it.

[weathertree4u]

49 minutes ago, Carvers Gap said:

While were are busying saying a post mortem for a month that hasn't occurred....LOL...enjoy the 18z GFS.  That is one way to make the MJO mute.  Cold overwhelms the pattern.

I like it but from what I hear here, it has no basis in reality lol 

[Carvers Gap]

32 minutes ago, weathertree4u said:

I like it but from what I hear here, it has no basis in reality lol 

Is it realistic in the face of evidence against it? Probably not because it is an outlier.  Is it a realistic path to exiting the upcoming warm pattern?  Sure.  It is not like we are asking for it to get cold in July - that is an unrealistic outlier.  The 18z GFS run was a realistic outlier with plenty of basis in reality.  I would be the first to admit that the run was wonky - it was not.  As stated above, get super cold in the front range and get a cutter.  Not a super difficult switch. Cold has overwhelmed MJO patterns in the past.  It will again.  With cold in the front range there is no physical feature to lock it into place there - just atmospheric pressure.  But I am not hanging my hat on one 18z run of the GFS...like never.  However, I said yesterday to assume I am "warm" in my thinking unless otherwise states.  I am just looking for ways out of this or just some oasis where we can get a cold shot or two.  I have seen locked-in cold patterns and locked-in warm patterns evaporate on modeling...patterns which had excellent synoptic support.  Sometimes the weather just doesn't cooperate.   Check out Bob Chill's comments in the MA forum regarding that run.  If we had been looking at a potential cold pattern for several weeks on modeling, and the 18z suddenly showed some warmth.  We probably wouldn't take it seriously unless another run backed it up...but I can guarantee all of us would be checking that next run just in case. Same deal here. 

[Carvers Gap]

FTR, the 18z run on modeling has thrown a wrench in many a forecast cold spell IMBY.  Probably doesn't continue, but who knows.  Just something fun to watch... 

[Carvers Gap]

Want a really good example of an EPS bust, look at last November(2018).  I was all-in on warm and made it clear.  John challenged the model, and he was right.  I have rarely seen the EPS so locked into a solution and see it bust.  November went cold.  It basically did the same thing this fall...but those were shoulder seasons and we are on different ground now as it is deep into winter.  But sometimes modeling can seem locked and miss.  So, never hurts to question modeling even if it is likely to be correct.  The GFS shows one way to cold compared to an abundance of paths going warm.  But again, if it was cold forecast and the 18z hiccuped...I would be watching the next few runs.