Mid to Long Range Discussion ~ 2023

[GaWx]

 The late 12Z GEFS taken literally (yes I know this is way out in Lala land and thus has limited credibility) says don't give up on the rare chance (only 1 in 25 odds based on last ~140 years) for a 3"+ snow month at RDU during an overall mild winter month. It suggests two Canadian highs may come down late this month with a somewhat split flow bringing in Gulf moisture up against a solid +PNA between the two highs. Again, just fwiw but that's appropriate speculation imo for this thread.

 Yes, the Canadian source regions will be mild for awhile. But keep in mind that even with that, a solid +PNA is usually cold relative to normals in the South. So, regardless of whether or not there'd actually be a winter storm threat, a pattern change to much colder late month is looking more and more likely.

 Edit: 12Z EPS is still on board for the colder change/+PNA for ~1/21. The trough axis is slightly further west than the 0Z, which is a good H5 flow for a potential winter storm wet/chilly vs dry/cold).

[NorthHillsWx]

18z GFS op run might be the worst mid January run from end to end I have ever seen. Absolutely not even close to anything anywhere in SE. GEFS was slightly better towards the end of the month 

[JoshM]

0z GFS, in a nutshell

[LakeNormanStormin]

As a UGA alum, tonight's domination makes me okay about the torch.

We can't win them all.

[GaWx]

 The 0Z EPS held onto the pattern change to +PNA/much colder very nicely. This goes back 4 or so days of runs now. The west coast ridge is the strongest yet. The mean trough is west of the SE allowing for ample moisture and a potential chilly wet period late this month, especially when also considering the progged drop in the AO.

[GaWx]

 The 3 major ensemble means continue to show a -AO late in their runs along with at least a moderate +PNA. This combo in itself is a positive for a BN dominated period in the SE late this month. Next up: 12Z EPS.

[BooneWX]

It’ll be great to have a +PNA, but one thing that concerns me is the position of the ridge on the west coast. The center of that ridge being in the eastern pacific just west of Seattle ain’t gonna cut it unless you’re moving to Ohio shortly. 

[wncsnow]

19 minutes ago, BooneWX said:

It’ll be great to have a +PNA, but one thing that concerns me is the position of the ridge on the west coast. The center of that ridge being in the eastern pacific just west of Seattle ain’t gonna cut it unless you’re moving to Ohio shortly. 

While that's true, the ridge will hopefully continue moving east past the 20th and setup in a better spot. 

[GaWx]

 The 12Z EPS is the strongest yet with its +PNA with (in dm at H5) +17 peak anomaly W coast and +15 peak E US. This is much stronger than the 12Z GEFS, which itself was stronger than its own 0Z. The 12Z CMC is similarly strong to the 12Z EPS. My very rough guess as to the 12Z PNA peak on the EPS is +1.5. How strong is that? The peak on 12/26/22 was +1.3. In January, the only ones since 1950 with a daily PNA peak higher were during 2016, 2002, 1995, 1981, 1977, and 1961. So, that is fairly rare in January (~8% of them).
 

 The GEFS mean based AO forecast is for ~-1 for then. So, what if the EPS isn't exaggerating the PNA (which it sometimes does) and there is a +1.5 PNA peak combined with a -1 AO? I wonder whether or not that is a significant indicator for cold in the SE in any part of January that has that.

[Upstate Tiger]

Thanks for all the work. Hopefully see something on Ops soon. Still like to see the NAO be neutral or negative but can’t have it all.  PNA is a more important teleconnection so I’ll take it.  

[Coach McGuirk]

Look at it this way, the snowless years make you appreciate the snow even more!

[strongwxnc]

5 minutes ago, Coach McGuirk said:

Look at it this way, the snowless years make you appreciate the snow even more!

Thats one way to look at it for sure. Im a little greedy though

 

[calm_days]

i don't know if there is a current thread for solar-terrestrial interactions, but this is at least interesting enough to post!!  I'm not sure of the hydrometeorological significance of this specific small interaction, but that the solar cycle is getting going and could make unique changes in some upper atmospheric and whole atmospheric phenomena is interesting to note as we wonder what the upcoming winter months, and seasons to follow, will be like!!

 

SOLAR FLARE CAUSES RARE 'MAGNETIC CROCHET': The X-flare of Jan. 9th did something rare. It jerked Earth's magnetic field. Here is a composite of magnetometer recordings from Boulder, Colorado; Honolulu, Hawaii; and Fredericksburg, Virginia:

Full recordings: FRD, BOU, HON. Credit: International Real-time Magnetic Observatory Network (INTERMAGNET)

The "jerk" is circled in yellow. It began around 1846 UT, and was detected by many magnetic observatories across the dayside of Earth.

The phenomenon is called a 'magnetic crochet.' Radiation from the flare ionized the top of Earth's atmosphere and caused currents to flow 60 km to 100 km above Earth's surface. These currents, in turn, briefly altered Earth's magnetic field. Everything returned to normal a few minutes later.

 

[PackGrad05]

The 23/24 time period looks like it could be worth watching.  EPS and GEFS both show some members with some snow for NC.  Way out I know, but the only thing even remotely interesting over next 2 weeks unless something random pops up.

[lilj4425]

You know things are bad when we’re depending on solar flares to help get us snow. 

[GaWx]

 Since November 23rd, there has been a -AO every day, which is 49 days straight. Today's GEFS 14 day forecast mean keeps the -AO steak going to the end, which would be 63 days in a row should it verify.

 

 Since 1950, longest -AO streaks: 

1. 102 days: 12/25/1959-4/4/1960

2. 69 days: 2/2-4/11/1958

3. 64 days: 2/5-4/9/2013

4. 63 days: 12/23/1962-2/23/1963

 

 So, if the GEFS mean were to verify, the current -AO streak would tie for 4th longest and be just one day from tieing for third. It would be 6 days from tieing for 2nd.

[wncsnow]

3 minutes ago, GaWx said:

 Since November 23rd, there has been a -AO every day, which is 49 days straight. Today's GEFS 14 day forecast mean keeps the -AO steak going to the end, which would be 63 days in a row should it verify.

 

 Since 1950, longest -AO streaks: 

1. 102 days: 12/25/1959-4/4/1960

2. 69 days: 2/2-4/11/1958

3. 64 days: 2/5-4/9/2013

4. 63 days: 12/23/1962-2/23/1963

 

 So, if the GEFS mean were to verify, the current -AO streak would tie for 4th longest and be just one day from tieing for third. It would be 6 days from tieing for 2nd.

 

Some interesting winters there. 1960 was the snowiest stretch in modern history for WNC where it basically snowed every week for a month or more and the national guard had to get called in to save mountain folks. 27 inches of snow fell at the Asheville airport in the month of March alone (much more in the mountains). 

 

2013 was one of the least snowy winters here the last 20 years with just a trace of snow and 1/2 of sleet and 1/10 freezing rain the only measurable winter precip imby and if I recall most of NC and SC saw below average snowfall that winter. 

 

Not sure about the other winters but thats a big range of options already. 

[GaWx]

46 minutes ago, wncsnow said:

 

Some interesting winters there. 1960 was the snowiest stretch in modern history for WNC where it basically snowed every week for a month or more and the national guard had to get called in to save mountain folks. 27 inches of snow fell at the Asheville airport in the month of March alone (much more in the mountains). 

 

2013 was one of the least snowy winters here the last 20 years with just a trace of snow and 1/2 of sleet and 1/10 freezing rain the only measurable winter precip imby and if I recall most of NC and SC saw below average snowfall that winter. 

 

Not sure about the other winters but thats a big range of options already. 

Thank you for that info. That's quite a contrast for wintry precip!

I just checked to add to your info by using RDU:

1960: March coldest by far on record; Jan N; Feb: B; Feb-Mar 18.7" SN/IP plus a good bit of ZR it appears!

2013: hardly any wintry precip; Feb N; March MB: 7th coldest, coldest since 1965

1958: 6th coldest Feb with 3.9" SN/IP; Mar tied for 5th coldest (T of snow) but that was El Niño

1962-3: 4th coldest DJF (behind 3 weak El Niño winters); major ZR 12/25, 7" snow in Feb

  So, regarding temps, all four long -AO periods were cold to very cold overall even though wintry precip varied a lot.

[wncsnow]

6 minutes ago, GaWx said:

Thank you for that info. That's quite a contrast for wintry precip!

I just checked to add to your info by using RDU:

1960: March coldest by far on record; Jan N; Feb: B; Feb-Mar 18.7" SN/IP!

2013: hardly any wintry precip; Feb N; March MB: 7th coldest, coldest since 1965

1958: 6th coldest Feb with 3.9" SN/IP; Mar tied for 5th coldest (T of snow) but that was El Niño

1962-3: 4th coldest DJF (behind 3 weak El Niño winters); major ZR 12/25, 7" snow in Feb

  So, regarding temps, all four long -AO periods were cold to very cold overall even though wintry precip varied a lot.

The 1960 winter is what all my grandparents talked about when they were here and aunts and uncles talk about still to this day. Snow drifts 8 to 10 feet high. Roads impassable for weeks to months. It's the standard for WNC and it all fell within 5 or 6 weeks pretty much in February and March. There were a few big (18 inch type) storms, but mostly 8-12 inch type storms repeating every 5 to 10 days (3 Wednesdays in a row at one point). I think 4 or 5 were gulf lows and there were lots of clippers and NWFS too. I think Boone had 6 feet or more in 6 weeks. 

 

Some pictures here https://www.citizen-times.com/picture-gallery/life/2019/12/16/historic-photos-1960-snowstorm-asheville-and-western-north-carolina/2665218001/

 

 

 

[wncsnow]

This is a good article on it with some meteorological background. Seems like the NAO was deeply negative. 

 

https://climate.ncsu.edu/blog/2016/03/hump-day-javu-the-three-wednesday-snows-of-march-1960/

[GaWx]

39 minutes ago, wncsnow said:

This is a good article on it with some meteorological background. Seems like the NAO was deeply negative. 

 

https://climate.ncsu.edu/blog/2016/03/hump-day-javu-the-three-wednesday-snows-of-march-1960/

  Great stuff!

  Per NOAA:

1. That 3/11/1960 storm gave Charleston accumulating snow and it nearly did that even down here! It was barely too warm and was just a very cold rain here per the records.

2. ATL had not one or two but THREE major winter storms in the first 11 days of Mar of 1960!!! (one ~4" snow and 2 mainly ZR/IP). That's insane!

3. Many areas of the SE had March temperatures that were BN for January! Get a load of this: March of 1960 was colder than any month of that as well as the prior met. winter!

 

 

[WeatherHawk]

4 hours ago, wncsnow said:

The 1960 winter is what all my grandparents talked about when they were here and aunts and uncles talk about still to this day. Snow drifts 8 to 10 feet high. Roads impassable for weeks to months. It's the standard for WNC and it all fell within 5 or 6 weeks pretty much in February and March. There were a few big (18 inch type) storms, but mostly 8-12 inch type storms repeating every 5 to 10 days (3 Wednesdays in a row at one point). I think 4 or 5 were gulf lows and there were lots of clippers and NWFS too. I think Boone had 6 feet or more in 6 weeks. 

 

Some pictures here https://www.citizen-times.com/picture-gallery/life/2019/12/16/historic-photos-1960-snowstorm-asheville-and-western-north-carolina/2665218001/

 

 

 

I grew up in the NC Piedmont...and my dad used to tell me about those 3 Wednesdays...back to back.  However, I'm afraid we've screwed up our climate, but hopefully it's not too late, if we can make some major changes soon.  If not, I fear the crazy stuff happening out in CA is just a tip of iceberg heading our way. 

[Upstate Tiger]

3 hours ago, WeatherHawk said:

I grew up in the NC Piedmont...and my dad used to tell me about those 3 Wednesdays...back to back.  However, I'm afraid we've screwed up our climate, but hopefully it's not too late, if we can make some major changes soon.  If not, I fear the crazy stuff happening out in CA is just a tip of iceberg heading our way. 

Likewise, my parents and grandparents spoke often about that famous March.  Grandfather said ice was on their back porch til the end of April.  I've heard this period referred to as the "Holy Grail" of SE weather patterns with a persistent cross polar flow that lasted throughout March.   

BTW...looking at overnight models.  The western ridge is showing up consistently in the long range but a Nina like Ohio Valley storm track continues to dominate.  Hopefully the ridge axis shifts a bit east.  Would not take a lot for the SE to be in the game with cold air over eastern Canada.  

[wncsnow]

15 minutes ago, Upstate Tiger said:

Likewise, my parents and grandparents spoke often about that famous March.  Grandfather said ice was on their back porch til the end of April.  I've heard this period referred to as the "Holy Grail" of SE weather patterns with a persistent cross polar flow that lasted throughout March.   

BTW...looking at overnight models.  The western ridge is showing up consistently in the long range but a Nina like Ohio Valley storm track continues to dominate.  Hopefully the ridge axis shifts a bit east.  Would not take a lot for the SE to be in the game with cold air over eastern Canada.  

Think that was the perfect example of what blocking can do when all the chess pieces are in the perfect spots. 

[NorthHillsWx]

06z GFS punts the pattern change till February, if at all

[NorthHillsWx]

GEFS gets a western ridge, but it’s situated too far west. That’s a cutter look late January 

[BooneWX]

55 minutes ago, NorthHillsWx said:

06z GFS punts the pattern change till February, if at all

The latter would probably be more likely in a Nina year. We desperately need things to flip this month or it might be time to start getting the lawn mower serviced.

[CaryWx]

47 minutes ago, BooneWX said:

The latter would probably be more likely in a Nina year. We desperately need things to flip this month or it might be time to start getting the lawn mower serviced.

Please look at the composite ensembles for the other major LR models.  Criminy folks

[BooneWX]

14 minutes ago, CaryWx said:

Please look at the composite ensembles for the other major LR models.  Criminy folks

I was just making a generalization about the pattern and likelihood of a Nina year producing Feb cold. We need those same ensembles to start showing a change in the medium range because they’ve been showing a long range “change” for about 2 and a half weeks.

[Met1985]

1 hour ago, NorthHillsWx said:

GEFS gets a western ridge, but it’s situated too far west. That’s a cutter look late January 

The freaking GFS  is broke. The government turn of mediocre model into shit.  Don't believe a dang thing that model spits out. The verification scores with that model since the upgrade have been atrocious.