GaWx

Looking back 115 years ago tomorrow, 4/25/1910, Atlanta had an absolutely amazing event: 1.5” of snow!!! The high on 4/25/1910 was only 39! After March 26th (going back to 1879), they have had highs below 40 only three times: 39 on 4/3/1987, 36 on 4/5/1891, and 39 on 4/25/1910. So, the 4/25/1910 very cold high really stands out in the record books for how late it is. This accumulating snow so late in April could easily be a once in several hundred year event and could even be a once in a thousand year event. The old Atlanta newspapers that I read (on microfiche at the public library) and copied forecasted rain and warmer temperatures on April 25th, not snow and colder. April 24th was 18 BN (high of 56 and low of 38) and they thought that that was to be the coldest day of the cold snap. So, this was a big surprise even to the meteorologists! Edit: It appears that even down at @dsaur’s location there was nearly 1”!!

I realize that. 1990-1 was quite mild. I even mentioned that in my subsequent post. He had no choice but to include it. But that doesn’t stop the 5 winter average from being quite cold (~-4). If the 5 winter average had not been cold, I seriously doubt that he would have even posted about the 2nd year La Nada analog so far in advance of next winter. His biggest problem is using 1991-2020 as climo for all 5. That makes these analogs average a solid cold -4, which is deceptive. It’s more like -2 using a more appropriate climo base as I said in the post you quoted.

-Don’t forget 1990-1. -I agree that 2014-5 is a 3rd year La Nada based on RONI even though the ONI is weak El Nino.

I worded that poorly. I should have said I followed his methodology. I just edited my original post. Yes, five is a small dataset. And of the 5, 1990-1 was mild. It’s easy to guess that JB is showing this because of his seemingly ever-present desire to forecast a cold NE US winter.

Yesterday, JB was already strongly hinting at a cold winter in the NE US and Midwest based on his expectation of it being the 2nd La Nada winter in a row. I follow his methodology, which is clearly explained. His analog 2nd year La Nada winters are 1960-1, 1967-8, 1990-1, 1993-4, and 2013-4. However, there are flaws in what he presented. -Even though 2024-5 was officially (i.e., per ONI) La Nada, it unlike his other 1st year La Nada winters in the dataset was clearly La Niña per RONI (it dipped all of the way to moderate Niña),which I think is more relevant. So, that disqualifies 2025-6 as potentially being a 2nd year La Nada from my perspective. -Somehow he left off the pretty cold winter of 1981-2, which clearly was a 2nd year La Nada per both ONI and RONI. -He included 1993-4. Although he’s right that that qualifies per ONI as a 2nd year La Nada, I’d exclude it because 1992-3 was a weak El Niño per RONI. -The biggest problem imho is that he uses 1991-2020, the warmest climo at the website, for his base climo for the entire dataset. That makes his analog map too cold considering that 1960-1 and 1967-8 shouldn't be using 1991-2020 as climo. Also, 1990-1 should use 1981-2010 for its climo. Even 1993-4, which I said I wouldn’t even include in the set, could arguably also more appropriately use 1981-2010 for its climo as 1993-4 is in the middle of that period. If it were me, I’d use 1951-2010 from the website’s choices for all of the years for the best balance rather than 1991-2020. So, this is JB’s map to try to predict 2025-6: centered near a quite cold -4 in NE/Midwest However, if I were to do it myself by accepting 2025-6 as a potential 2nd year La Nada winter, I’d get it centered near -2 for the NE/Midwest instead of -4: still chilly no doubt but with only half the anomaly that JB’s map has:

That’s exciting! I hope the experiments are successful.

Since that mid April IRI 3.4 projection model summary was released, the CFS 3.4 progs have cooled significantly. It had had (per what I bolded above) +0.62 in OND and was still rising. Now, based on the image below, OND is only ~+0.05. So, any chance that there had been for weak El Niño (though only small), which had been based on the +0.62 in OND, is even smaller by a good bit. I’m saying that as of now the chance for a weak El Niño has dropped to extremely low. I won’t say near zero yet only because it’s too early. But I’m probably at 5-10% at most. 4/22/25 Nino 3.4 CFS run: OND only +0.05 @jburnsplease pin this thread and unpin El Niño 2023-2024. That one is just a bit outdated.

@donsutherland1and others, This is from Joe Bastardi today. He’s totally convinced that that large amount of cooling in the Atlantic (20N to 20S) over the last year is due to a >50% drop of seismic activity in the “mid-ocean spreading zone” because the area of cooling surrounds a portion of the Atlantic part of that zone. Any comments?

Thanks for posting this. Here are my thoughts fwiw: 1. The Euro has a significant warm bias from spring predictions. The April run has Nino 3.4 max at only +0.42 (in JAS) before starting to drop. Considering its warm bias, that in itself is signaling a trimonth peak near 0. 2. However, the CFS, which has tended to have a cool bias the last 2 years, is one of the warmest with a peak of +0.62 in OND and still rising slowly. That tells me to not completely dismiss the chance for a weak El Niño. 3. MetFrance over the last 2 years has averaged a modest warm bias though it has missed somewhat too cold in some months. It’s April has a peak of +0.19 in ASO and still very slowly rising. If anything, that suggests a trimonth peak that could be ~~0. 4. BoA (Aus-Access) has it up to +0.57 in JAS and still very slowly rising. Due to a strong warm bias in 2023, a moderate warm bias in 2024, and this being the warmest for ASO of any major dynamic model, I feel this is signaling a low end warm neutral. 5. I consider the combo of the UKMET and the JMA as having the lowest bias of any kind. The UK has -0.31 in JAS (coldest of major dynamic models) and still falling significantly. The JMA has -0.14 in ASO and still falling slowly. These two suggest cold neutral as being most likely in autumn. 6. So, based on the above, I currently favor anywhere from ~0.0 to cold neutral for autumn to winter. 7. None of this takes into account RONI, which I currently favor to be at least 0.3 cooler than ONI. So, RONI could drift into weak La Niña territory based on UK/JMA.

Here’s some good news for a change:

I see very little chance for El Niño at this point. The only thing that I recall that ever explicitly hinted at it was CANSIPS a number of months ago when looking ahead to August showing a significant central Pacific equatorial warming. However, it has since been modifying this each run and no longer shows anything of note. In addition, Nino regions have cooled notably from highs in March/earlier this month (see below). When also considering the Euro’s notable warm bias in spring for the subsequent autumn, I’d also say very low chance. La Niña may very well have a better chance than El Niño.

I agree as I see very little chance for El Niño at this point. The only thing that I recall that ever explicitly hinted at it was CANSIPS a number of months ago when looking ahead to August showing a significant central Pacific equatorial warming. However, it has since been modifying this each run and no longer shows anything of note. In addition, Nino regions have cooled notably from highs in March/earlier this month (see below). When also considering the Euro’s notable warm bias in spring for the subsequent autumn, I’d also say very low chance. La Niña may very well have a better chance than El Niño.

Because it was straight warming from the prior Niña and DJF was up to +0.1

2012-3, 2001-2, 1996-7, 1985-6, 1950-1, 1943-4, 1934-5, 1894-5, 1875-6, 1870-1

-Those 2 each had a major SE snow. -85-6 had “deep SE” snows -Nov 1950 had alltime record Nov cold in SE -Other: 1996-7 had nothing overly notable in SE -1894-5 had the coldest and snowiest Feb on record in the SE

This looks to end up as the 2nd earliest major SSW that also ends up as a FW since records began in 1958. This one reversed ~3/9/25 and has remained reversed since. The earliest on record is Mar 5th (2016). The 3rd earliest is Mar 11th (1984).

If anyone is interested in a Masters contest, go to the sports forum’s PGA thread. Thanks.

Heavy thunderstorms now coming into the Atlanta area. I’d get off the road now if you can or delay any driving if you’re able to.

Per JB today: if the downward trends continue, we should see a slowdown in the thermohaline circulation, coupled with declines in SST and lower tropospheric temps going forward. We MAY be at the inflection point we've wanted to see. Fingers crossed! ——————— Global seismic activity (Mw 5.3 and greater) from 1/1/1977 - 12/31/2024. Data in yellow indicate yearly projections for 2025 but should be accorded low confidence at this time. @donsutherland1

That was for 4/3. For 4/4, RDU’s low was 73, which beat old record by 10, is new alltime April high min beating 72 of 4/29/2017, and crushed the old earliest in season 73 by 38 days!

Thank you, Chuck. I did conclude that CSU has had an overactive bias in April though only when it had a very active forecast. This is a link to what I posted on 4/7/24, which addressed that: Here’s how 2024 actual ended up vs CSU’s extremely active April prediction. Indeed, they once again came in too active in most though not all categories: NS: 23 (too high by 5) NS days: 115 (too high by 38) H: 11 (perfect) H days: 45 (too high by 7.5) MH: 5 (perfect) MH days: 13 (too high by 1.5) ACE: 210 (too high by 48) This year’s April predictions are for a still active season but not nearly as active as they were calling for last April: NS: 17 vs 23 NS days: 85 vs 115 H: 9 vs 11 H days: 35 vs 45 MH: 4 vs 5 MH days: 9 vs 13 ACE: 155 vs 210 So, these are significantly lower than last April and thus seem quite reasonable as Chuck implied. So, unlike last year, I don’t feel comfy saying that the April CSU #s have a good chance to come in too high. Actually, I’m not predicting either way right now.

Yes, GFS backed off a good bit again for the lows on 4/9. It like usual has been jumping around. Now the Euro is colder than the GFS for then (they’ve been trading places). And now the coldest for the GFS is later (4/11) with its coldest run for then yet (major outlier and thus I expect the next few runs to not be as cold for 4/11. 4/3 12Z Euro for 4/9’s lows: 4/3 12Z GFS for 4/9’s lows: 4/3 12Z GFS for 4/11’s lows:

Good news, Tony. Since early yesterday FFC pulled back on the prior forecasted high of near 90 at ATL for tomorrow to the upper 80s, similar to RDU. Both cities’ highs are now forecasted to be in the upper 80s for tomorrow and Saturday.

The March 2025 30 mb QBO came in at +11.82, a slight rise vs Feb. I still think this has a good chance to go negative by summer.

12Z runs for April 9th minimums: GFS (not quite as cold as that very cold 6Z): Euro (not as cold as GFS):