January Medium-Long Range Discussion

[Carvers Gap]

17 minutes ago, Matthew70 said:

It’s fun to actually feel like we’re tracking.  This is within 10 days.  Pretty incredible. 

Still a long way to go.  Models (I am sure) are not done bouncing around.  I have tracked potential cold like this.  Sometimes it results in a simple cold front - frustrating!  And sometimes it results in December '22 which were the coldest wind chills(with the exception of 1985) that I have ever felt.  As you and I have discussed, we still have dead shrubs in our yards or at least rough looking shrubs.  I have one bush that is still shedding leaves over a year later!   My fig tree was taken back to the roots.  It killed one of my rosemary plants.  

I do like what I see on ensembles.  Honestly, we probably have a better chance of snow if they are correct.  We will obviously get a better idea of what the details are during the coming days for sure.  This is a very dynamic and fluid set of circumstances w/ the STJ potentially interacting(or not) with cold air, and also the MJO still lurking.

Fun day.  I hope we have more of it tomorrow.

[GaWx]

24 minutes ago, Carvers Gap said:

See the post right above the one you just posted....

Yeah, I think most know to take that type of run with a grain of salt, but I don't discount it(just think it is highly unlikely).  I should note that isn't the only model to show that type of extreme during that past few days.  So, if the GFS is wrong, it won't be alone.  The CMC and Euro control have both had some crazy cold runs.   The CMC had a 1074 high at 12z.  It is very rare for an extreme of that nature to verify, but it is not without precedent in NE TN w/ snowfall present.  So, I wouldn't say it is unrealistic.  It has happened before, and likely will occur again.  We have seen that type of cold here a few times in my lifetime - 85, 94, 96, and I am sure I am missing several years.   That said...just last December('22) modeling portrayed -30 to -40 below zero wind chills here(over snowless ground), and nailed every bit of it.  

In 1985, it hit -24F where I lived.  Wind chills were off the cart.  I was under my house trying to thaw out pipes.  I probably sat it a K-Mart parking lot helping my dad change an alternator around that time as well.  It was brutal. 

And I should add, that it isn't just modeling currently showing those extremes.  The CPC has used 1994, 1996, and 1985 in their analog packages during the past few days.  Maybe those are GFS generated.  IDK.  

I will always say that to be right in the weather, always bet against the extreme - always.  One will rarely be wrong.  I can concur with that, and that is true now as well.  We will for sure know more during the coming days.  Moderation is usually the trend, and we know that.

 

I follow you. I just wanted to make sure that y’all were aware of the fresh snowcover bias. Regarding the CMC, it overall has a colder bias than the GFS. I don’t mean just over snowcover. I mean in general.

 Even if it doesn’t get as cold as the 18Z GFS but it still gets very cold, that would mean quite possibly the second winter in a row with the coldest of the season when the MJO was in a moderate to strong MC phase.

[Carvers Gap]

6 minutes ago, GaWx said:

Even if it doesn’t get as cold as the 18Z GFS but it still gets very cold, that would mean quite possibly the second winter in a row with the coldest of the season when the MJO was in a moderate to strong MC phase.

I think for middle and west TN this is correct.  I will have to check for MBY in NE TN.  We have been saddled to the MJO for three years in MBY, and it grows tiresome!!!!   But, I do think your observation is interesting.  Likely, the redevelopment of the NAO during winter is maybe responsible for that?  We went many years without decent NAO blocking.  It would show-up during late March or April, but we could never seem to get it during winter.  So, maybe Atlantic blocking can be a trump card to a bad Pacific?  Just spitballing, but maybe.   As you have very accurately noted, the warm phases of the MJO do have exceptions to the rule.  

[dwagner88]

6 hours ago, WinterWonderland said:

I live in Anderson County, TN in Oak Ridge and the snow we had in Feb 1996 was incredible. One of the best I've seen in my life time and I'm 68 yrs old. With that particular storm, the mets were not predicting snow, but heavy ice. In inches. The thought of it icing that much was scary. That evening it started sleeting and 30 min later changed to all snow and stayed snow. Never had any ice thank goodness. Here in town we got about 18 inches and I have never seen snow fall that heavily, and straight down cause there was no wind. Businesses closed and people were walking instead of driving. The streets were literally snow packed and it snowed off and on for two weeks. We did a LOT of sledding! Anyway, sorry to be so long with my post, but it truly was a magical time. I even journaled it and glad I did! I just wished I'd gotten some pics!

Sent from my Pixel 3 using Tapatalk
 

I can't remember if it was the Feb storm or the big Jan 96 blizzard, but one of those storms gave us almost 6" of sleet down here. It was like a marble countertop everywhere. Absurd sledding. MRX is missing KCHA ASOS data from that winter, so I can't look up when it actually happened.

[GaWx]

Does anyone have the latest EPO forecast from the EPS or any model? TIA

[Daniel Boone]

1 hour ago, Carvers Gap said:

See the post right above the one you just posted....

Yeah, I think most know to take that type of run with a grain of salt, but I don't discount it(just think it is highly unlikely).  I should note that isn't the only model to show that type of extreme during that past few days.  So, if the GFS is wrong, it won't be alone.  The CMC and Euro control have both had some crazy cold runs.   The CMC had a 1074 high at 12z.  It is very rare for an extreme of that nature to verify, but it is not without precedent in NE TN w/ snowfall present.  So, I wouldn't say it is unrealistic.  It has happened before, and likely will occur again.  We have seen that type of cold here a few times in my lifetime - 85, 94, 96, and I am sure I am missing several years.   That said...just last December('22) modeling portrayed -30 to -40 below zero wind chills here(over snowless ground), and nailed every bit of it.  

In 1985, it hit -24F where I lived.  Wind chills were off the cart.  I was under my house trying to thaw out pipes.  I probably sat it a K-Mart parking lot helping my dad change an alternator around that time as well.  It was brutal. 

And I should add, that it isn't just modeling currently showing those extremes.  The CPC has used 1994, 1996, and 1985 in their analog packages during the past few days.  Maybe those are GFS generated.  IDK.  

I will always say that to be right in the weather, always bet against the extreme - always.  One will rarely be wrong.  I can concur with that, and that is true now as well.  We will for sure know more during the coming days.  Moderation is usually the trend, and we know that.  But...there is nothing on any model run that I would consider unrealistic.  Highly unlikely?  Absolutely, and we know that.  Without precedent? No. Though, they do flirt w/ all-time record lows....they are sill within reason of the region's most extreme weather.  Honestly, those wind chills are similar to what many experienced in December of '22.

 

February 20, 2015 is another for your list . 20-25 below in Mountain Valleys with deep Snow pack here in Lee County. Pennington gap recorded -20 officially. So, yeah not unrealistic. That was late Winter ! 

[Silas Lang]

Obviously nothing is set in stone, but it is hard to not love the trend on the GFS for the post MLK day storm. Still a long ways to go, but man, models have typically been all over the place, especially this far out. The consistency is extremely alluring. Talk me back guys. 

 

[Holston_River_Rambler]

7 hours ago, GaWx said:

Does anyone have the latest EPO forecast from the EPS or any model? TIA

[GaWx]

50 minutes ago, Holston_River_Rambler said:

Thank you. So, the 0Z 1/7/24 EPS mean has maintained the Jan 11-18 period of near or sub -150 (-1.5) that was on the 0Z 1/4/24 run. An 8+ day long period of -150 or lower has occurred about once every two winters on average since 1948 with no winter having more than two of them. This EPS run is implying that the low of this period would probably be sub -300.

https://downloads.psl.noaa.gov/Public/map/teleconnections/epo.reanalysis.t10trunc.1948-present.txt

[ShawnEastTN]

I can't remember if it was the Feb storm or the big Jan 96 blizzard, but one of those storms gave us almost 6" of sleet down here. It was like a marble countertop everywhere. Absurd sledding. MRX is missing KCHA ASOS data from that winter, so I can't look up when it actually happened.

Yes! I live about 70 miles north of Chatt but that's what we got too a crazy ton of sleet with just a little snow on it at the end.

Sent from my Pixel 7 using Tapatalk

[Carvers Gap]

Models are feeling the MJO this morning.   It will be interesting to see if they continue trending that way today.  They have the MJO rolling into phase 4 by the 15th.  By the 21st, modeling(running on about a 7 day lag) has a ridge in the East.  So, I think our window is reasonably set.  From Jan 14-21st.....that is the first real window and probably need to focus on that last storm in the series.   Of note, the Euro ext rolls that ridge right on through, and it gets cold after about a week of what will likely be a welcomed warm-up.

Whew! The 6z GEFS and 0z GEPS got colder last night.  Their ensemble snow means(GEPS/GEFS) are much stronger today for the entire state.  The 0z EPS is warmer(not crazy warmer or anything like that) so that is something to watch.  

Operational modeling was off-and-on a bit warmer overnight.  However, we are seven days out from what is likely the first cold front to roll through.  The core of cold air arrives about 5 days after that - I think(I probably should go back and check).  I still think it wise to let the ensembles lead this.  

As a final note, when extremely cold air is forecast for the United States....modeling(especially operationals) are going to bounce around all over the place.  As a general rule, I think modeling tends to very much underestimate how far surface level cold advances.  Beware of ice.

[Carvers Gap]

Cosgrove had his weekly update last night.  Here is a quote from him:

That rare case of a cAk vortex in Michigan is important in that it will be very tough for anyone living east of the Rocky Mountains to see any warm air. Most of the schemes show a brief  moderation to the right of the Mississippi River and Great Lakes in the 16-20 day time frame. But the weeks 5 and 6 outlines seem to have a +PNA/-AO/-NAO alignment.So for all of you who were singing the blues about being bypassed for winter from the Great Plains to the East Coast, this is a chance for normality. And maybe something more. Like perhaps a "for real" snow and ice event in the Mid-Atlantic and New England states in the last week of January and much of next month.

[Matthew70]

2 hours ago, Carvers Gap said:

Cosgrove had his weekly update last night.  Here is a quote from him:

That rare case of a cAk vortex in Michigan is important in that it will be very tough for anyone living east of the Rocky Mountains to see any warm air. Most of the schemes show a brief  moderation to the right of the Mississippi River and Great Lakes in the 16-20 day time frame. But the weeks 5 and 6 outlines seem to have a +PNA/-AO/-NAO alignment.So for all of you who were singing the blues about being bypassed for winter from the Great Plains to the East Coast, this is a chance for normality. And maybe something more. Like perhaps a "for real" snow and ice event in the Mid-Atlantic and New England states in the last week of January and much of next month.

Does he not think the MJO will rule the pattern?

[Daniel Boone]

2 hours ago, Carvers Gap said:

Models are feeling the MJO this morning.   It will be interesting to see if they continue trending that way today.  They have the MJO rolling into phase 4 by the 15th.  By the 21st, modeling(running on about a 7 day lag) has a ridge in the East.  So, I think our window is reasonably set.  From Jan 14-21st.....that is the first real window and probably need to focus on that last storm in the series.   Of note, the Euro ext rolls that ridge right on through, and it gets cold after about a week of what will likely be a welcomed warm-up.

Whew! The 6z GEFS and 0z GEPS got colder last night.  Their ensemble snow means(GEPS/GEFS) are much stronger today for the entire state.  The 0z EPS is warmer(not crazy warmer or anything like that) so that is something to watch.  

Operational modeling was off-and-on a bit warmer overnight.  However, we are seven days out from what is likely the first cold front to roll through.  The core of cold air arrives about 5 days after that - I think(I probably should go back and check).  I still think it wise to let the ensembles lead this.  

As a final note, when extremely cold air is forecast for the United States....modeling(especially operationals) are going to bounce around all over the place.  As a general rule, I think modeling tends to very much underestimate how far surface level cold advances.  Beware of ice.

The ice thing is what has me concerned. I started to touch on that last night. Many times when an Arctic airmass dives into the west then gradually presses east and southeastward you get an an off and on stall as waves ride the front and the SER fights against it. If my memory serves me correctly, many if the Ice occurences in our area were also during warm ph MJO Periods.

I can remember the OV getting lambasted with Heavy Snow while we just got cold enough for freezing rain with ultimately no Snow and a very modified glancing blow of what was a huge Arctic Airmass I think in January if 89 or 90. Wish I hadn't lost my Records. 

    Let's hope this doesn't come to a scenario like that. 

[John1122]

GFS is gonna be a big one for at least Western areas and maybe the whole forum area. Looks better than 00 or 06z.

[Matthew70]

19 minutes ago, John1122 said:

GFS is gonna be a big one for at least Western areas and maybe the whole forum area. Looks better than 00 or 06z.

I’d feel more comfortable if the GFS was not alone.  Though ensembles do favor the GFS.  Euro is one I like to have saying yes instead of no. 

[jaxjagman]

32 minutes ago, Matthew70 said:

Does he not think the MJO will rule the pattern?

I know,but where is the MJO actually gonna be at?Seems to me it has the potential as it goes into the Maritime  to start heading back towards the COD with the possibility of going back into the NH much faster than the Euro is showing

[Carvers Gap]

The 12z CMC is flirting with greatness.  The cold outbreak at the end of that run is simply brutal, and like the 18z GFS last night, a glimpse of the pattern’s potential.  Wow.

[jaxjagman]

21 minutes ago, jaxjagman said:

I know,but where is the MJO actually gonna be at?Seems to me it has the potential as it goes into the Maritime  to start heading back towards the COD with the possibility of going back into the NH much faster than the Euro is showing

To add onto to this the MJO does a loop basically,this is from a strong  Kelvin wave moving across Africa today and will enhance the MJO signal into the western IO

[Carvers Gap]

The good thing about that loop....it appears to push the MJO more quickly through the warmer phases.  It is less of a crawl.  It only takes 7 days to get across 4 and 5 instead of 15 as some previous models runs had it.  It makes me think that time in warm phases will be short lived.

[jaxjagman]

5 minutes ago, Carvers Gap said:

The good thing about that loop....it appears to push the MJO more quickly through the warmer phases.  It is less of a crawl.  It only takes 7 days to get across 4 and 5 instead of 15 as some previous models runs had it.  It makes me think that time in warm phases will be short lived.

Me too,just look at the MJO starting back Nov 25 with the CHI map i posted,we saw the strong Pac Jet coming off Asia,it shouldn't be as strong right now but its still coming by the models

[Daniel Boone]

25 minutes ago, Carvers Gap said:

The good thing about that loop....it appears to push the MJO more quickly through the warmer phases.  It is less of a crawl.  It only takes 7 days to get across 4 and 5 instead of 15 as some previous models runs had it.  It makes me think that time in warm phases will be short lived.

Also, relatively low Amp looks like. We can handle that with good blocking I think.

[Carvers Gap]

I think the GEPS ensemble has this - meaning it is correctly modeling the pattern.   

[1234snow]

The 12z CMC is flirting with greatness.  The cold outbreak at the end of that run is simply brutal, and like the 18z GFS last night, a glimpse of the pattern’s potential.  Wow.

It was a major shift from the 0z CMC where on that run it dumped the trough out west at the end of the run.

[1234snow]

The 12z ICON made a similar move as the CMC with moving the trough and cold air eastward at the very end of the run. -63 degrees show up in the model for 12z Jan 14th just north of the border of Montana.

[Silas Lang]

Runs not over, but it looks like the Euro is caving towards the GFS as well. Good trends overall today if you want snow. 

[Carvers Gap]

The 12z GFS looks to warm in relation to it own ensemble and other modeling.   

[tnweathernut]

3 minutes ago, Silas Lang said:

Runs not over, but it looks like the Euro is caving towards the GFS as well. Good trends overall today if you want snow. 

Euro will cut.  Northern and southern stream started interacting with each other way out west….   Maybe it’s a step in the right direction, time will tell.  There are differences even at hour 120 evident, so will likely work out the correct (west vs east) sooner than later.

[Silas Lang]

1 minute ago, tnweathernut said:

Euro will cut.  Northern and southern stream started interacting with each other way out west….   Maybe it’s a step in the right direction, time will tell.  There are differences even at hour 120 evident, so will likely work out the correct (west vs east) sooner than later.

Yeah, maybe cave was too strong, but it looked like an improvement on the surface from the 0z run at least. 

[Carvers Gap]

Both the Euro and CMC oddly have followed the 18z GFS in producing extreme temperatures racing eastward.  Both end as the cold air enters west TN.  We will see what the Euro control has....