GaWx

22, 96, 84

The GEFS and EPS have big disagreement 12/25-1/3! Fwiw, JMA, BOM, and CFS favor GEFS: Meanwhile, phase 8 , which helped bring strong cold Dec 3-7 and Dec 15 but won’t next week, returned on 12/17 and will likely be with us for awhile:

I loved the 3 week cold stretch! I’m still enjoying the cool/dry of yesterday and this weekend. Great for walking! Was down to mid 30s this AM. The impressive torch is progged to be most concentrated during 12/23-8 (and much of that period will still be pleasant with pretty low dewpoints) and with any later torchy days up in the air since good model skill doesn’t go out that far. Despite the warmup Charlotte will still likely end up NN for Dec. ATL likely slightly AN. RDU/GSO likely slightly BN.

Strong SPV during cold and snow Nashville since 79: -Jans of 25, 22, 16, 00, 96, 84…so, 6 of 14 cold and snowy Jans had strong SPV (00 cold/snow last half of Jan) -Feb of 96 Strong Jan SPV has been progged by Euro Weeklies, which have and usually do well:

Todays Euro Weeklies are looking better/pretty good for 1/12-2/1. See the main ENSO thread for maps/more details if interested.

I’ll add that today’s weeklies have a stronger -NAO/-AO forming for 1/12-2/1: 1/12-18: 1/26-2/1:

Today’s Euro Weeklies are similar to the prior ones through Jan 11th with mild for much of the country though the warmest is closer to the C US, well away from the E US. However, today’s weeks 4-5 continue yesterday’s cooling trend: 1/12-18 12/17 run: 12/19 run: 1/19-25 12/18 run: 12/19 run: And then week 6 is similar to yesterday’s in the E US: In summary, whereas the first 3 weeks (through 1/11) remain mild in much of the E US, the last 3 weeks (1/12-2/1) are mainly NN to a little BN in most of the E US with nothing even resembling warmth. The 1/19-25 map suggests a +PNA is trying to form:

The 12Z GFS has 6 days of the rest of Dec having a high of 70+ at KATL (12/24-29): 70, 73, 72, 70, 71, and 73. Granted, 2 of the 6 days on this barely make 70. So, getting 6 won’t be easy. Many models including earlier GFS runs don’t have 70+ on 12/29 with the 5 of 12/24-28 more common for the most. That being said, IF it were to actually occur, 6 days of 70+ at KATL within 12/20+ would obviously be a very impressive anomaly! How rare would that actually be? Extremely! It’s only occurred three times since 1878: -2021 (warmest 75) -2015 (warmest 77) -1984 (warmest 74) Needless to say, this will be very interesting to follow!

The 12Z GFS has 6 days of the rest of Dec having a high of 70+ at KATL (12/24-29): 70, 73, 72, 70, 71, and 73. Granted, 2 of the 6 days on this barely make 70. So, getting 6 won’t be easy. Many models including earlier GFS runs don’t have 70+ on 12/29 with the 5 of 12/24-28 more common for the most. That being said, IF it were to actually occur, 6 days of 70+ at KATL within 12/20+ would obviously be a very impressive anomaly! How rare would that actually be? Extremely! It’s only occurred three times since 1878: -2021 (warmest 75) -2015 (warmest 77) -1984 (warmest 74) Needless to say, this will be very interesting to follow!

As I just posted, this time a year ago had a much colder weeks 3-4 outlook than now. But I also said that a somewhat better comparison might be how it looked for Jan 2022 at this time, when instead of one of the coldest week 3-4 outlooks on record for the SE half of the US, it was suggesting a mild SE half of the US (including Mid-Atlantic) was a better possibility: A little after this point in Dec of 2021, when there was a similar very strong -PNA to what’s being forecasted for late Dec, the weeks 3-4 outlook was far different than it was in 2024: How did Jan 8-21, 2022 verify in Greensboro, NC? They ended up 4 BELOW normal and had two 1”+ snowfalls. So, one would have had no clue from NOAA even as late as Dec 24th that a cold Jan of 2022 in much of the E US was incoming.

I agree that this is nothing like how Jan, 2025 was looking at this point in Dec of 2024, when the Euro Weeklies were much colder and this was the NOAA weeks 3-4 outlook, one of the coldest on record for the SE half of the US: AAM forecast had this then: Current AAM forecast: A somewhat better comparison might be this time in Dec of 2021, when there was a similarly very strong -PNA, Christmas was looking very warm, and there were still no strong hints on the 2 week guidance that a huge change was on the way although some CFS runs were cold in part of Jan.

Well, I just added something to my last post that may cheer you up. The models are actually suggesting a good chance this moved right back into 8 either yesterday or today! So, we might go right back to celebrating as early as tomorrow!

Talk about a turnaround! After one day of glee and bigtime celebration due to our immense accomplishment of getting phase 8 back, it’s already gone. The MJO moved into phase 7 two days ago. Turn out the lights, the party’s over (well as of two days ago at least). But the good news is that the models are suggesting a good chance this moved right back into 8 either yesterday or today! So, we might go right back to celebrating as early as tomorrow!

Todays Euro Weeklies are still not great by any means but they are a bit colder/less mild during 3 weeks of the 4 weeks starting with week 2: 12/29-1/4 yesterday 12/29-1/4 today 1/12-18 yesterday 1/12-18 today 1/5-11 was also a little colder today **Edited for corrections needed in my captioning because I had “today” and “yesterday” reversed. Today’s are less mild as I said.

I have it by luck on my phone as I happened to start saving a few in Dec of 2021 and Jan of 2022 I think because of long range hints on the CFS (of all models, which I also saved a bunch of…so kudos to the CFS then!) starting to show very long range big colder changes in late Dec and especially Jan. Since then, I happened to have saved a lot near and after the 2/16/2023 SSWE, which showed that the -NAO/-AO were initially way underdone/missed. Since then I’ve saved a bunch during the winters. I’m not aware of these being available to the public.

On 12/26/21, when the PNA had been negative all month/way down at -1.8 that day and Baltimore (among others) had just had a miserably mild 68F Christmas high with very mild to continue through New Year’s, this (see image below) was the 12/26/21 GEFS two week PNA forecast, which went to 1/9/22: still down at -0.6 on 1/9/22 and no clearcut sign that 1/9/22 was going to be the start of a 38 day long +PNA as well as Jan ending up the snowiest month by far there since Jan of 2016 along with it being the coldest month since Jan of 2018: @donsutherland1 *Edit: The main points are: - The models can’t see out that far with notable skill and that includes forecasting the PNA/general patterns - -ENSO -PNA Decembers since 1984 all transitioned to +PNA Jans

-Actually, Dec of 1996, indeed, was still another -ENSO strong -PNA that transitioned to a +PNA in Jan after a 1.8+ rise. -Dec of 1999 had a neutral PNA. So, that isn’t in this group. *Corrected for typo…Dec of 1999

I’m very curious to see what happens in Jan with the PNA based on -ENSO strong Dec -PNA analogs like 2021, 2013, 2010, 2008, and 1984 whose Jan PNA all rose 1.8++ from Dec. That’s still well beyond what models can see with any notable degree of skill. My GEFS PNA forecasting images for Dec 2021-Jan 2022 displayed that well.

Yeah, way out in fantasyland! This reminds me of this Euro storm from last January in not as far out fantasyland: While this was gone on the very next run, this turned out to be when the historic 1/21-2/2025 Gulf coast/deep SE winter storm occurred.

Hey Don, This is somewhat related and something I happened to compile yesterday about big NC snowstorms during -PNAs. First, note that the -PNA for the 2010 storm was only weak (-0.3). Also, what’s interesting about the list below of big NC snows during a -PNA is that only one of the 7 most -PNA 6”+ storms there were during a -NAO! Anyone know why or is this likely just from randomness? It’s a somewhat decent sized sample of 7 and 4 of the 7 had a moderate to strong +NAO as opposed to just a weak +NAO: 6”+ storms since 1950 at GSO and/or RDU: most negative PNA:-1.1: 2/12-13/2014 (moderate +NAO)-0.8: 1/22-24/1954 (moderate +NAO)-0.8: 3/2-3/1960 (neutral NAO)-0.7: 1/6-7/2017 (moderate +NAO)-0.5: 3/9/1960 (neutral NAO)-0.3: 12/26/2010 (moderate -NAO)-0.3: 2/24-26/2015 (strong +NAO)Daily PNA: https://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.pna.index.b500101.current.ascii Daily NAO: https://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.nao.index.b500101.current.ascii

The -NAO continues to be very strong for late this month per the 0Z GEFS and EPS:

This Euro storm reminds me of another at 9-10 days out released on 1/12/25 that caused social media to get way out of control and even caused me to be texted in the middle of the night from an Atlanta friend due to his Facebook feed from this as if it were credible: But this did turn out to be when the historic Gulf coast/deep SE winter storm occurred (1/21-22/2025).

Ladies and gentlemen, can I have your attention, please? The results are in and we did it. The MJO went back into phase 8 on Dec 15th, the coldest day of the season to date! Let the celebrations begin! The weenies are gonna party like it’s Feb 1899!

Natural gas closed up nearly 4%, easily its best day since Dec 5th. This is largely based on today’s forecast speculation that the forecasted dominant warmth may not be as widespread, intense, and/or long lasting in the E US as thought yesterday thanks largely to the newly forecasted strong -NAO.

The model consensus is currently forecasting the strongest -NAO on Christmas as well as surrounding days since way back in 2010! In stark contrast, these 6 had a strong +NAO: 2011, 13, 15, 16, 23, and 24.