February 2024 mid/ long range

[Holston_River_Rambler]

I have to think precip. won't be a problem and bowling ball lows in a few weeks. Even though the Maritime continent shallow ocean heat is still intense, the past few weeks have seen the biggest winter time SOI drops since I've been posting.

 

The end of that Euro run was nice, if you like cold. Looked like shortwaves getting slung its way too. 

[Carvers Gap]

LOL.  I knew that would happen.  Send me a Christmas card.

The EURO (aka Dr No) pours cold water on early spring talk....man. It traps a piece of the TPV, and there she goes.  That is a classic SSW response.  That is a -EPO/-NAO couplet.  

 

[Holston_River_Rambler]

I'm probably gonna

A) be wrong

and

B ) get a comment about slinging spaghetti on a wall

but I think we are about 7 - 10 days away from seeing a meaningful end to this cluster             of a pattern we've been in. I was really hoping about this time last week we'd see some better signs by yesterday or today and yeah the Euro above is nice, but I'd like to see all ops at least showing a way out.

Doesn't have to be an epic look. Doesn't mean it has to show snow. All I'm asking is for two weeks without a trough slamming into California. Hopefully the Euro is the first hint of changes brewing. 

 

That satellite imagery Jeff posted yesterday is not too encouraging, but if we can believe the GEFS RMM today (updated late) the mean splits the difference of 30 members between several big phase 8-1-2, several CODs, and several, I guess, status quos: 

 

I especially like the one member that goes back to phase six and stays there for a week. 

GFS OP likes the COD. I still think it lo amp/ borderline traverses COD 8-1-2-3. If it plays out like it did in January, our best chance for a January redo may be around the Raindancewx date of March 1. 

[Daniel Boone]

8 minutes ago, Holston_River_Rambler said:

I'm probably gonna

A) be wrong

and

B ) get a comment about slinging spaghetti on a wall

but I think we are about 7 - 10 days away from seeing a meaningful end to this cluster             of a pattern we've been in. I was really hoping about this time last week we'd see some better signs by yesterday or today and yeah the Euro above is nice, but I'd like to see all ops at least showing a way out.

Doesn't have to be an epic look. Doesn't mean it has to show snow. All I'm asking is for two weeks without a trough slamming into California. Hopefully the Euro is the first hint of changes brewing. 

 

That satellite imagery Jeff posted yesterday is not too encouraging, but if we can believe the GEFS RMM today (updated late) the mean splits the difference of 30 members between several big phase 8-1-2, several CODs, and several, I guess, status quos: 

 

I especially like the one member that goes back to phase six and stays there for a week. 

GFS OP likes the COD. I still think it lo amp/ borderline traverses COD 8-1-2-3. If it plays out like it did in January, our best chance for a January redo may be around the Raindancewx date of March 1. 

JMA has that low amp 8123. Maybe it'll score a coup

[Carvers Gap]

The 12z Euro control went freaking bonkers w/ the cold.  I doesn't even look like the 0z run.  The ensembles does provide some support for that.  Man, this reminds me of the mid-Jan cold snap.  The models didn't have it...until they did.  Time will tell.  

[Carvers Gap]

1 hour ago, Holston_River_Rambler said:

I'm probably gonna

A) be wrong

and

B ) get a comment about slinging spaghetti on a wall

but I think we are about 7 - 10 days away from seeing a meaningful end to this cluster             of a pattern we've been in. I was really hoping about this time last week we'd see some better signs by yesterday or today and yeah the Euro above is nice, but I'd like to see all ops at least showing a way out.

Doesn't have to be an epic look. Doesn't mean it has to show snow. All I'm asking is for two weeks without a trough slamming into California. Hopefully the Euro is the first hint of changes brewing. 

 

That satellite imagery Jeff posted yesterday is not too encouraging, but if we can believe the GEFS RMM today (updated late) the mean splits the difference of 30 members between several big phase 8-1-2, several CODs, and several, I guess, status quos: 

 

I especially like the one member that goes back to phase six and stays there for a week. 

GFS OP likes the COD. I still think it lo amp/ borderline traverses COD 8-1-2-3. If it plays out like it did in January, our best chance for a January redo may be around the Raindancewx date of March 1. 

I think the NAO is the gonna be the driver.  We did this dance during January.  Once the NAO got its act together, things started shaking.  Plus, we are in the zone where the SSW (not the current one, but it could be I guess), but the one before could be showing up on mid range modeling and long range.

edit:  all we need is the MJO(like you have there) to just be not so much a pain in the neck, but just let the potential NAO drive the pattern and force confluence.

[Itryatgolf70]

58 minutes ago, Carvers Gap said:

I think the NAO is the gonna be the driver.  We did this dance during January.  Once the NAO got its act together, things started shaking.  Plus, we are in the zone where the SSW (not the current one, but it could be I guess), but the one before could be showing up on mid range modeling and long range.

edit:  all we need is the MJO(like you have there) to just be not so much a pain in the neck, but just let the potential NAO drive the pattern and force confluence.

It's interesting that the euro is really the only model showing it that cold. If the tpv really goes to southern Canada, the models, imo, should be much colder. Maybe they will catch on. That Raindance guy is good from what I understand but he gets the bighead sometimes. I would take a cold March if we can get a ULL out of it that supports snow

[Itryatgolf70]

Also, the -pdo hurt us alot, which isn't typical in a niño. Very interesting pattern. I'm still hoping we can get enough cold and moisture for one more opportunity here. ULL can provide alot of snow. If the tpv is the real deal, models should adjust accordingly and we got a -epo, which should also allow for a colder pattern than what's indicated imo. 

[Daniel Boone]

28 minutes ago, Itryatgolf70 said:

It's interesting that the euro is really the only model showing it that cold. If the tpv really goes to southern Canada, the models, imo, should be much colder. Maybe they will catch on. That Raindance guy is good from what I understand but he gets the bighead sometimes. I would take a cold March if we can get a ULL out of it that supports snow

Yeah, Radiance did good overall with his outlook. A bit warm in our area with his January call. 

[nrgjeff]

Indeed @Itryatgolf70 this unusual combo of -PDO and El Nino has been fickle. It's how we get a great storm track, but putting cold air in place is like pulling teeth - without Novocain. 

[PowellVolz]

Yeah, Radiance did good overall with his outlook. A bit warm in our area with his January call. 

Yeah I think we are done. Outside of a surprise (March 21’) and a few cold days after a front, I’m turning towards spring severe.


.

[Carvers Gap]

The PDO has been a pain.  We discussed that in depth last fall as a potential thorn.  It certainly(more times than not) puts the default trough in the West.  

That said, the Mountain West has been STRUGGLING w/ precip deficits.  Could be a very rough summer there.  Fortunately, I think Jackson, WY, got some snow this week.   So, it is not helping them a ton.  There are snow machine businesses that haven't been able to run their machines in the dead of winter.  Cooke City, MT, had bare ground two weeks ago, and their main street was pavement.  I have never seen that during winter.  If the PDO was fully on board, there would likely not be bare ground there.   But.......it is incredibly common to have severe cold in the eastern Valley, and then that be it for winter.  Same was true for me as a kid.  I did wonder when it got so cold, if that might be it.  

But I tell ya where it has been cold - Alaska.  I follow Stan Zuray (Yukon Men) on Facebook.  He is a great follow on social media.  He is a fisheries expert.  He has been posting about how cold the interior has been there.  

I think the main culprit this winter was the December GOA low on steroids that created that monster chinook.  It scoured Canada of snow, and made it tough to rebuild the cold there.  To me that has been a problem.  If that had not occurred, we would have been cold from the last week of December through the third week of January.  We managed to get some of that snow/cold deficit back, and even get back into positive territory in terms of snow...but I think that chinook put us in the hole from a source region standpoint.  

But let's see....January changed-up unexpectedly.   It certainly looks like a warm signal, but the atmosphere doesn't have to do what modeling says.  The storm/no-storm on the 18th could change things up much like the Plains storms did in early Jan.

[Daniel Boone]

18 minutes ago, PowellVolz said:

Yeah I think we are done. Outside of a surprise (March 21’) and a few cold days after a front, I’m turning towards spring severe.


.

Not looking great really. The Pacific has really hurt us once again. The Block may still allow for at least one more shot this month. 

[Carvers Gap]

Also, my general rule for pattern durations is 4-6 weeks.  I really just didn't' want to admit that at the time(Jan21st), but that has come to pass.  If that rule holds, the can kicking into late Feb make sense.  That means the actual pattern is Jan 21-end of Feb.  I can almost use that rule and never look at an MJO cycle, and I should have done that this time around. It works almost as well as "thunder in the mountains."  What we thought was a thaw, was really a true pattern change.  I think on modeling we are actually watching models struggle w/ the next pattern change later this month.  The beginnings of that change begin next week.  Remember when the pattern was can-kicked by several days during December?  Same deal IMHO.  

To be clear, pattern changes don't mean better snow chances.  I am simply talking wx at this point.  We need pretty incredible cold come March at this latitude.  But I do think we are going to see a -NAO build.  Is the EPS wrong?  Possibility.  But it really deepened that feature on the 12z EPS run.  Normally, I would just say that warmth is coming and mail it in.  But I am skittish after what happened during January, and modeling missed a monster cold shot.

[John1122]

2 hours ago, Daniel Boone said:

Not looking great really. The Pacific has really hurt us once again. The Block may still allow for at least one more shot this month. 

The strong pac jet is mauling any attempts at blocking there. This time of year it's hard to get cold enough for snow without Pacific help. The models were showing a developing -EPO that stayed in place, but now they are briefly showing it going negative and it moves out quickly. The snow/cold in January coincided with a major EPO ridge. It was negative for 6 days and it unloaded cold onto us. Most of our sub zero type cold comes from -EPO incidents. 

[Carvers Gap]

Right now it is the GEFS vs EPS/GEPS....there is not consensus that a warm-up is permanent.  It may well be the reality, but that is not the case right now.  Pretty substantial model war under way.  The GEFS has had a really bad warm bias this winter. 

[Daniel Boone]

35 minutes ago, John1122 said:

The strong pac jet is mauling any attempts at blocking there. This time of year it's hard to get cold enough for snow without Pacific help. The models were showing a developing -EPO that stayed in place, but now they are briefly showing it going negative and it moves out quickly. The snow/cold in January coincided with a major EPO ridge. It was negative for 6 days and it unloaded cold onto us. Most of our sub zero type cold comes from -EPO incidents. 

Exactly. Need at least a brief interlude of -EPO to inject enough cold with right timing of a Storm System as is with upstream blocking in place. May be enough cold for the higher eles to score regardless with proper Track but, would be tough for lower eles. 

[Itryatgolf70]

9 minutes ago, Carvers Gap said:

Right now it is the GEFS vs EPS/GEPS....there is not consensus that a warm-up is permanent.  It may well be the reality, but that is not the case right now.  Pretty substantial model war under way.  The GEFS has had a really bad warm bias this winter. 

For the time being, the tpv over southern Canada keeps me intrigued. In all seriousness, models should be colder than indicated. Also, Raindance saying beginning of March should resemble mid Jan with a cold blast. Doubt it, but anything is possible. 

[Daniel Boone]

10 minutes ago, Carvers Gap said:

Right now it is the GEFS vs EPS/GEPS....there is not consensus that a warm-up is permanent.  It may well be the reality, but that is not the case right now.  Pretty substantial model war under way.  The GEFS has had a really bad warm bias this winter. 

Very true. The last upgrade apparently implemented too much warmth adjusting. 

[Carvers Gap]

46 minutes ago, Daniel Boone said:

Very true. The last upgrade apparently implemented too much warmth adjusting. 

Modeling was completely blind to the mid-January even until just days prior.  Big storm wen through the Plains and modeling flipped.  I think we are going to have to get this system worked out on the 18th, before we know for sure the hand we are dealt.  

I honestly don't buy the EPO stuff this winter.  We got a decent rotation of the MJO and the NAO fired.  It got cold as the NAO pattern matured.  The EPO helped some, but without that NAO, the cold wouldn't have been there at all.  Same was true last winter.  The reason we have seen severe cold during the last 4-5 winters is the NAO is beginning to fire again.  We went a couple of decades without a true NAO negative trend.  In E TN especially, the EPO is not always a driver.  The storm that brought snow to this area just three weeks ago was driven there by the NAO block.  The EPO would have not allowed for confluence.   E TN almost always does better for snow w/ an NAO block, and that was true this winter w/ Knoxville seeing that record snowfall.

[Carvers Gap]

We just need the Pacific not to have massive jet extensions....that has been a problem for several winters.  I have my theories on why this is occurring(one of you knows my thoughts), but I do wonder.  

[Carvers Gap]

1 hour ago, Itryatgolf70 said:

For the time being, the tpv over southern Canada keeps me intrigued. In all seriousness, models should be colder than indicated. Also, Raindance saying beginning of March should resemble mid Jan with a cold blast. Doubt it, but anything is possible. 

The beginning of March is within the window that we have been talking about since mid Jan.  Glad he is discussing that.

[John1122]

I just disagree about the EPO and how it shapes winter events here. Our best/historical winter events are very much tied to -EPO events, and the most epic ones feature the holy trinity of -EPO/-NAO/-AO, (the temp in Nashville in Jan 1963 dropped 61 degrees with 6 inches of snow in a day when they aligned, which happened fairly often in the 1960s). However a lot of our big events and extended winter periods are EPO driven more so than NAO driven.

 

. This last event in Jan was so impressive because the EPO sent the cold from Siberia/Alaska into the lower 48 and we got a historic duration snow depth record in Knoxville due to it.  The EPO is the bringer of cross polar flow. The NAO was only negative for the first two days of it. The EPO was negative through the week and we remained in the ice box, setting up the additional freezing rain/snow and sub zero cold. When the EPO flipped positive we warmed up 42 degrees in a day 36 hours or so after it flipped and were 50 degrees warmer than we'd been 48 hours earlier the day after that. 

Sometimes we get the -NAO too but often it's a non-factor in our big winter events. The -EPO being absent for big winter (cold/snow) events is more rare in my experience. 

Just looking at our winter events that are memorable to me in the last 40ish years and some notable storms and winter periods a bit earlier.

 

Jan 1st - 15th 1981, 5 inches of snow, 7 days with lows between -1 and 1. +NAO, -EPO. EPO went positive and we warmed up. EPO crashed again by Jan 30th. 4 inch snow event and 0 lows by the 31st. The NAO was neutral/ very +. The EPO remained super negative through mid Feb. Snow fell on 6 of those days and we were below 10 for lows for 8 days with a low of -8. The NAO was very positive the entire time. Knoxville departures from normal during that timeframe were -5, -10, -20, -14, -17, -4, -7, -6, -4, -10, -27, -14. The EPO flipped positive and the rest of the month torched. The NAO actually went neutral/negative during the warm up. 

December 2001 we had a prolonged deeply negative NAO for two weeks. The EPO was very positive and we baked in 70 degree December weather. The EPO went negative around Christmas and suddenly we went  BN. 

The only downside of the -EPO is that it can get dry. It rarely ever fails to deliver cold. 

 

Other memorable events and the teleconnections. 

Epic Jan 1951 winter storm to close the month. Deeply -EPO/+NAO

Big March 2022 event. A week of -EPO set the stage. The NAO was + throughout. 

Blizzard of 1993  neutral/+ NAO, -EPO

February 1996 major snow, super cold, neutral/ rising NAO / very -EPO when we bottomed out at -20 on Feb 4th. 

Dec 1989 record cold. Massive -EPO/ +NAO

January '88 major snow +NAO/-EPO

Jan 29th-30th 2010. mildly -NAO (-0.3) with very -EPO

Jan 10-13 2011, cold, snowy with huge snow event that got most of the forum.  Very -EPO with neutral, rising into + NAO.

2015 epic mid-late February cold/frozen precip,  very +NAO/ -EPO

April 1987 huge snow neutral/+NAO/-EPO

March 1980 big snow/very cold +NAO/-EPO

January 1994 extreme cold/snow +NAO/-EPO

Epic 1998 paste job neutral  NAO/-EPO 

2004 Feb 15th event mentioned in the historic thread. 6 straight days of -EPO leading into it. +NAO.

It's way less common to see big winter here with a +EPO and -NAO combination but I'm sure it's happened. It's also happened with both being neutral or mildly positive. (we got a major Christmas snow in 1969 with both the NAO and EPO positive, but the EPO had been moderately negative a few days before it and the NAO had been mildly negative. The picture below is the NAO for January 1-24th 1978. The EPO was deeply negative during this time frame. 

It featured below zero temps and 12-20+ inches of snow across the region. 

This is why I always want the Pacific on our side. From Mountain City to Memphis the EPO is usually involved in the big winter threats. 

[jaxjagman]

We could get a storm in the long range if the teles work in our favor it seems maybe just a slim chance.The last couple days there was a system going into the Yellow Sea and South Korea basically,so chances are we should see a system further south of us.Right now looking at the teles its gonna be to far south and not really much ample cold air,just something to watch

Sure looks cold tho by Euro AK Rex block and -NAO,probably just cold for us here and more chances if anything for the eastern people

[Holston_River_Rambler]

I've got the H5 gifs from the January system. It looks to me like the EPO knocked the cold our way and then the NAO modulated the TPV in central Canada in just such a way so that the moisture aimed at the the TN Valley. I don't have the H5 gifs for afterwards though.

Alphabet soup indices incoming:

 

I hate to break solidarity with the TRI folks, but I am more of an EPO/ PNA person. This is not an attack on y'all. I love you and want you to live! But y'all can do better with a -NAO that the rest of the TN Valley. If we hadn't had the EPO dislodge the cold and the PNA spike, the TPV that drove the flow beneath it and aimed the moisture at us, might have been pushed by the NAO back to Seattle. (-PDO FTW then?) -NAO 100% helped in that situation, but there was an arm of the TPV acting as a 50/50. I've decided it is not the NAO I want for storms here, it is a semi permanent 50/50 low. You know how the troughs seem to magically try to always drop into the Southwest these days, I want a trough to be like that in the 50/50 spot. You don't have to worry about the NAO then. There will automatically be higher heights over the Davis Straits and Greenland in response to the 50/50. Kind of like Jax's pic above.

I guess we have to wait until the AMO flips, or as the Capital Weather Gang alleged a few days ago, the Atlantic Meridional Overturning (another AMO) dies and the Atlantic dramatically cools. 

 

Honestly I think the January storm was a very rare set up in terms of the Continental synoptics. I don't think 8-10 inches of snow is as rare as some of the news folks who were saying this was our biggest snow since '93., but the TPV being in just the right place at just the right time and to have the NINO STJ there too was unique. It really was like a colder, drier version of my rainy "firehose" pattern, like we saw yesterday in some parts of the state.

Lord have mercy, how I would love to see the .qpf we had yesterday and overnight as snow!

 

 

Flooding gifs. Discussion of the MJO and SSWs. EPO vs. NAO. It must be February in the TN Valley! 

We need the guidance of the elk more than ever in these godless, commercial times. 

 

@Greyhoundhave you taken the abomination down yet? It may wish to be removed. Not blaming you or anything, but creepy metal snowmen can be fickle. 

 

Glad to see the 6z GFS showing more cold in the long range. Even got some TN Valley snow under 200 hours! OP Euro still bringing some cold on the 0z run too. 

This latest SSW looking less impressive to me lately, but I think we will see some atmospheric fallout around mid March. 

Welp, I'm off to float down the road in my raft. Will post pics if I survive or catch any food to feed the neighborhood. 

 

 

 

 

[Daniel Boone]

24 minutes ago, Holston_River_Rambler said:

I've got the H5 gifs from the January system. It looks to me like the EPO knocked the cold our way and then the NAO modulated the TPV in central Canada in just such a way so that the moisture aimed at the the TN Valley. I don't have the H5 gifs for afterwards though.

Alphabet soup indices incoming:

 

I hate to break solidarity with the TRI folks, but I am more of an EPO/ PNA person. This is not an attack on y'all. I love you and want you to live! But y'all can do better with a -NAO that the rest of the TN Valley. If we hadn't had the EPO dislodge the cold and the PNA spike, the TPV that drove the flow beneath it and aimed the moisture at us, might have been pushed by the NAO back to Seattle. (-PDO FTW then?) -NAO 100% helped in that situation, but there was an arm of the TPV acting as a 50/50. I've decided it is not the NAO I want for storms here, it is a semi permanent 50/50 low. You know how the troughs seem to magically try to always drop into the Southwest these days, I want a trough to be like that in the 50/50 spot. You don't have to worry about the NAO then. There will automatically be higher heights over the Davis Straits and Greenland in response to the 50/50. Kind of like Jax's pic above.

I guess we have to wait until the AMO flips, or as the Capital Weather Gang alleged a few days ago, the Atlantic Meridional Overturning (another AMO) dies and the Atlantic dramatically cools. 

 

Honestly I think the January storm was a very rare set up in terms of the Continental synoptics. I don't think 8-10 inches of snow is as rare as some of the news folks who were saying this was our biggest snow since '93., but the TPV being in just the right place at just the right time and to have the NINO STJ there too was unique. It really was like a colder, drier version of my rainy "firehose" pattern, like we saw yesterday in some parts of the state.

Lord have mercy, how I would love to see the .qpf we had yesterday and overnight as snow!

 

 

Flooding gifs. Discussion of the MJO and SSWs. EPO vs. NAO. It must be February in the TN Valley! 

We need the guidance of the elk more than ever in these godless, commercial times. 

 

@Greyhoundhave you taken the abomination down yet? It may wish to be removed. Not blaming you or anything, but creepy metal snowmen can be fickle. 

 

Glad to see the 6z GFS showing more cold in the long range. Even got some TN Valley snow under 200 hours! OP Euro still bringing some cold on the 0z run too. 

This latest SSW looking less impressive to me lately, but I think we will see some atmospheric fallout around mid March. 

Welp, I'm off to float down the road in my raft. Will post pics if I survive or catch any food to feed the neighborhood. 

 

 

 

 

Started to put a laugh emoji due to the elk epo thing but, figured wasn't appropriate for the balance of the post. Lol

[jaxjagman]

Yeah i wasnt laughing at the post,the soup in funny

[Carvers Gap]

You all can dig up my old NAO posts.  It is a key driver for E TN snowstorms.   There isn’t a ton of debate on that.  It is also a key driver in many Kocin storms.  For middle and west TN, the EPO is more important as those areas just don’t benefit very often from coastals.  -NAO has driven many snow storms during the past 4-5 years. It produces confluence.  Without it, everything races out to sea.  When we lost the NAO during late Jan, we torched.  
 

This is key...The NAO will often force the Western ridge to form as the upstream NAO ridge backs flow, forcing a trough over the East, and forces an almost upside down omega by buckling the jet northward as it crosses the West coast.  Without the block over Greenland, the upstream ridge will often not form over the eastern PAC.   It buckles the jet.  Without the NAO, the jet doesn’t buckle this winter.  That is just atmospheric physics.   January’s pattern was NAO driven as it forced the upstream jet to buckle.  And I do have the saved maps for that sequence and also many other recent storms - whenever I ran out of memory on Am Wx...I moved my graphics to cloud based servers.
 

Because E TN is closer to the Atlantic, it makes sense that the Atlantic is our main driver.  When I get time, probably over the summer as I am getting next winter’s forecast ready, I will pull some analytics.  (Now, we haven’t talked about a PNA which is different.).  I will take individual storms and look at those.  Seasonal readings don’t tell the story.  They have to be system by system.  Often NAOs won’t last the entire season.  They can sometimes be brief.  What the NAI does is buckle the jet.  That backs up flow and will often force or sharpen the ridge over the eastern PAC.   Plenty of evidence of that in many great eastern snow storms.

[Carvers Gap]

I will add some scientific journal articles about the NAO itself.  Its influence on EC wx/climatology is well documented and well studied.

But again, the 6z GFS has hopefully a trend towards a colder Feb 18 system.

[Holston_River_Rambler]

1 hour ago, jaxjagman said:

Yeah i wasnt laughing at the post,the soup in funny

No worries @jaxjagman or @Daniel Boone I was trying to ride a line between serious and funny.