GaWx

In addition to a suggested warm bias of the Euro ensemble and probably some other models, the current subsurface is another reason to feel that a super Nino is only at a low chance. The current subsurface has the warmest anomaly below Nino 3.4 at just over +3 C. I'll call it +3.25. That's a good indicator of impending El Niño: But, compare this to those at this time of year before both the 2015 and 1997 super Ninos: 2015: warmest anomaly near +5.5 C: 1997: warmest anomaly near +6 C: So, whereas a significant El Niño is still likely based on the subsurface below Nino 3.4, a super Nino is not being suggested based on the subsurface comparisons of warmest of +3.25 now vs +5.5 in 2015 at this time and +6 in 1997 at this time.

In developing El Niños since 1982, the fastest 3 month warmings in Nino 1+2 prior to the current 3.5 were: - In 1997, it was 3.0 (Apr 16-July 16 of 1997): rose only 0.2 subsequent 4 weeks to that Nino's max followed by fall of 0.9 the two weeks after that - It also rose 3.0 Feb 26-May 28 - Fastest in 1982 only 2.3 - Looking back at other Niños that reached 2.0 in Nino 3.4 (1972-3, 1965-6, 1888-9, 1877-8), the fastest 3 month warming in Nino 1+2 was only 2.25. - So, with Jan of 2023 being -0.35, climo suggests that it won't be easy for April of 2023 as a whole to average much more than about +2. Thus, the +2.7 that was just released smells strongly like a max at least for awhile. So, I kind of expect a "correction" or at least a stall of sorts in Nino 1+2 for at least the rest of this month as history suggests this highly volatile relatively small region's 3.5 warming in 3 months has sort of gotten ahead of itself. It wouldn't at all surprise me if it cools notably in the update to be released this coming Monday though that isn't an outright prediction.

Have 1+2 anomalies recently warmed the fastest on record? - it has risen 3.5 the last 13 weeks/3 months, the fastest on record (since 1982) for 13 weeks just beating the old of 3.3 set Feb-May 1983 - fastest in 2 weeks is 2.3, set in March of 2003, twice as fast as the fastest two weeks this time Going back to 1870 (monthly), the fastest one month rise has been 1.95, set April to May, 1905. I don't think that will be broken. The fastest two month rise has been 2.65, set in Jan to March of 1957. It exceeded 2.0 two other times: - rose 2.32 Feb to April 1935 - rose 2.19 April to June 1997 - depending on how well the rest of April holds the warmth, there will be a chance for Feb to Apr to exceed 2.0.

The last two evenings have been absolutely beautiful and perfect for walking. Tomorrow will be another. Meanwhile, I saw a red fox in my backyard this afternoon! It didn't appear to just be passing through as it was out in the open for several minutes and in no hurry to leave. So, there may be a den in my bushes near the fence in back or perhaps in the back yard of the neighbor behind me. I do recall seeing several foxes (sometimes together) around my property (including walking in the middle of the quiet street at night) last year.

Looking back all of the way to 1870, here's a link to monthly SST anomalies in Nino 1+2: https://psl.noaa.gov/gcos_wgsp/Timeseries/Data/nino12.long.anom.data Looking at April, the warmest April monthlies all of the way back to 1870 in 1+2 by far are 1998 and 1983, which were as previously mentioned after rather than before their respective El Niño peaks. All other Aprils were over a degree cooler! I then focused on April anomalies in Nino 1+2 just prior to the El Niños that reached +2.0+ in Nino 3.4 for 3 month averaged periods: 2015, 1997, 1982, 1972, 1965, 1888, and 1877. - 2015: +0.6 - 1997: +1.0 - 1982: -0.5 - 1972: +1.1 - 1965: +1.7 (warmest of any pre-Nino April back to 1870) - 1888: +0.9 - 1877: +0.0 The first week of April of 2023 was +2.7. But it is as many know by far the most unstable Nino region from week to week. So, it could easily fall back sharply during the next few weeks. But if it doesn't fall back much, we'd end up with by far the warmest pre-El Nino April in Nino 1+2 for all El Niños back to at least 1870! We'd be so far into uncharted territory.

For an ONCOMING El Niño in the highly volatile Nino 1+2, the current +2.7 is way warmer than any other one in April since 1982. The old record warmth in 1+2 during April in an oncoming Nino back to 1982 was +1.3 set in 2015 and in 1997. April 2015 peaked at +1.3 April 2009 peaked at +0.6 April 2002 peaked at +1.1 April 1997 peaked at +1.3 April 1982 peaked at -1.0 (yes, it was still negative) https://www.cpc.ncep.noaa.gov/data/indices/wksst9120.for

Here's the way I'm looking at the ENSO climo from year to year based on looking at the combination of the CPC table since 1950 and Eric Webb's tables prior to 1950 that go back to 1850: - The greatest rise since 1850 in the 3 month average from one fall/winter to the next is 3.1, which was from the 1971-2 moderate Niña to the 1972-3 super Nino. - Next largest rises were 2.9 (1996-7 to 1997-8), 2.8 (1964-5 to 1965-6), 2.6 (1975-6 to 1976-7 and 1917-8 to 1918-9), 2.5 (1924-5 to 1925-6), 2.4 (2008-9 to 2009-10 and 1981-2 to 1982-3), 2.3 (1910-1 to 1911-2), and 2.2 (1956-7 to 1957-8 and 1898-9 to 1899-1900). - So, there have been 11 rises greater than 2.0 since 1850. The 2022-3 ENSO dipped to a low of -1.0. So, in order for 2023-4 to reach super Nino strength (+2.0+), it would take THE largest rise since the late 1800s (the 3.1 rise from 1971-2 to 1972-3) to accomplish that. - Based on this, alone, the chances of a super Nino peak in 2023-4 are low. - It would take a rise of 2.5 to 2.9 to get a strong Nino peak in 2023-4. There have been five rises of 2.5 to 2.9 since 1850. That, alone, suggests a significantly higher chance for a strong Nino peak than a super Nino peak in 2023-4. - Fwiw after adjusting for an implied warm bias, the April 1st Euro ensemble is suggesting that the highest chance is for strong over high end moderate or super. - Thus, as of now, I'm leaning toward a strong Nino three month averaged peak (+1.5 to +1.9) as most likely for 2023-4 with high end moderate (+1.3 to +1.4) as second most likely and super (+2.0+) as third most likely.

46.7 here now and 46 at KSAV/KSVN as of 3AM with drizzle and a steady N wind. That's crazy raw for down in this area in April! Corduroys on April 8th!!

Today has been a cloudy/wedgy day though with not much rain yet. At KSAV, the highest so far today is 57, which is tied with the record low high. The Masters had one of its most miserable golfing days ever with it suspended at mid afternoon.

Trees fell at the Masters due to winds! Thankfully, apparently nobody was hurt, thanks to just enough warning time as a result of cracking sounds just before the trees hit the ground to allow spectators to scramble. Here's the video: 0425 PM NON-TSTM WND DMG 2 NNE AUGUSTA DANIEL FI 33.50N 82.03W 04/07/2023 RICHMOND GA BROADCAST MEDIA BROADCAST MEDIA REPORTED TWO LARGE PINE TREES FELL NEAR THE 17TH TEE BOX AT AUGUSTA NATIONAL GOLF COURSE. SOCIAL MEDIA PHOTOS ALSO CONFIRMED THE DOWNED TREES. TIME ESTIMATED BY RADAR AND COINCIDES WITH THE COLD FRONT PASSAGE. NO INJURIES REPORTED.

At 2PM: 82 CAE vs 48 CLT!

Per the link below, DJF EPO for 1972-3 averaged modestly negative with D/F averaging negative and Jan positive. The EPO tended to have one to two week long periods alternating between + and -. Daily EPO: https://downloads.psl.noaa.gov/Public/map/teleconnections/epo.reanalysis.t10trunc.1948-present.txt The Deep South had not just one but two historic winter storms that winter (though in different areas): 1) The aforementioned record breaking snowstorm of Feb 9-11, which even gave us way down here a very rare 3.2" thanks to a GOM Miller A storm that crossed way south (central FL). That was at the end of a weeklong solid -EPO. There was a slight +PNA, a strong +AO, and a +NAO: https://www.weather.gov/ilm/Feb1973Snow 2) A terrible icestorm that was at or near the worst ever in Atlanta Jan 7-8, which was in the midst of a 12 day long solid -EPO, a short-lived strong -NAO (one of only three that season), a slight +AO that was surrounded by strong +AO, and a neutral PNA. There was a very cold, large 1045 mb high centered over the N Plains with CAD/E winds ridging way down on the E side of the Appalachians being overrun by moist, mild WSW flow (with a very weak Gulf coast low): Maps: https://library.oarcloud.noaa.gov/docs.lib/htdocs/rescue/dwm/1973/19730108-19730114.pdf Story: https://www.army.mil/article/198866/45_years_ago_georgia_national_guard_responds_to_1973_winter_storms

That's him! In the latest from "57", it appears that he's subtly caved somewhat. Earlier he said "non-tropical", which usually implies neither tropical nor subtropical since subtropical has some tropical characteristics. Now he's saying "not remotely tropical" and that the NHC could classify it as "STS Arlene": "I do think that a low pressure center will develop south of Louisiana next Tue-Wed, but it will not be remotely tropical. Winds may reach 35kts along the SE LA coast by Wednesday. We see these type of low centers often during the winter months. Wouldn't put it past the NHC calling it STS Arlene. Winds may peak at 35-40 kts, with little chance of becoming stronger, given the extremely high wind shear over it. High pressure to its north will produce the gradient north of the low center."

Per another BB per pro met "57": "WSW jet stream of 80-110 kts over the NE Gulf next week. Looks like a non-tropical west Gulf low. Not uncommon in winter and early spring. Tremendous shear" With it being only April and with the GFS having numerous fakes the last few years, I'm going with "57" on this even knowing that he tends to be bearish.

So, the April 1st Euro ensemble mean 3.4 plume for ASO is ~+1.7. How does this compare to some past actual El Niño ASOs? 2015: +2.2 1997: +2.1 1965: +1.9 1972, 1982: +1.6 1957: +1.3 1963: +1.2 For these 7, the average increase from ASO to peak was 0.4 with a range of 0.1 to 0.6. So, that would imply based on the April 1st Euro ASO forecast of +1.7 a later peak between +1.8 and +2.3 (mean of +2.1). https://origin.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ONI_v5.php Keep in mind though that none of this takes into account whatever forecast bias the Euro may or may not have (see below). And of course even if the bias is negligible, there is mean forecast error to keep in mind when looking ahead that far (as much as 6 months). How does the April 1st Euro plume mean of +1.7 for ASO compare to some past April 1st Euro progs for ASO? - 2017: +1.1 (the year of worst forecast) vs -0.4 actual - 2015: +2.0 vs +2.2 actual - 2014: +1.5 vs +0.2 actual - 2012: +1.0 vs +0.4 actual - 2009: +0.8 based on May 1st forecast vs +0.7 actual So, for these 5 years, the April 1st forecast mean for ASO ended up too warm 4 times and too cool once. On average for these five years, the April forecast for ASO was 0.6 too warm. Even if I were to throw out the 2017 forecast debacle, the April forecast for ASO for the remaining four years was still 0.45 too warm. So, perhaps the April 1st forecast for ASO has a too warm bias. If so, the odds would favor the actual ASO end up lower than +1.7. But regardless, the +1.7 ASO prediction being the 2nd warmest for the Euro in April is a significant indicator that a pretty robust El Niño is probably on the way. Even if I were to reduce the +1.7 ASO forecast to +1.2 or +1.3 to account for Euro warm bias, that would still imply that the later peak would most likely end up in the strong (+1.5 to +1.9) category though most likely not super-strong and with high end moderate also in the mix. Then again, the trend from last month's Euro forecast is significantly warmer. So, we'll see! Lots of uncertainty but the chance for a robust El Niño has increased significantly from last month based on the Euro.

The trend from last month's plume is significantly more robust (see last month's plume below). Per eyeballing the Euro ensemble mean for each month: - July increased from March 1's forecast of ~+1.0 to this forecast of ~+1.3. - Aug increased from ~+1.1 to ~+1.5 - Sep increased from ~+1.2 to ~+1.8 - So, JAS increased from ~+1.1 last month to ~+1.5 this month. - Oct is ~+1.9 - So, ASO is ~+1.7 on this month's. - Keep in mind that this is based on 1981-2010 climo. But even if it were based on 1991-2020, it would be about the same per this: https://origin.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ONI_change.shtml ------------ Last month's not as robust plume for JAS, which was near +1.1:

Maybe they had AN entire E coast in an earlier winter forecast. However, their latest one as per this link had AN only on the SE US coast with NN NE US: https://www.weatherbell.com/final-winter-2022-23-forecast

937 mb is high for a cat 5. This must be because background pressures were higher than usual increasing the pressure gradient. There was a 1030 mb Canadian high that had come down into the MW. I bet that had something to do with it. Had that instead been, say, 1020 mb or lower, I bet it wouldn't have made cat 5.

The GFS suite the last few runs has continued to say "What cold? The suite had for days been showing a cold shot (30s lows much of the SE) for 4/12-13. Now that period on it is near normal at the coldest.

Here (and in a lot of the SE) today was a near perfect day for outdoor activities with sunshine, pleasant temperatures, and very low dewpoints. I took advantage of it with an early evening walk.

The 6Z GFS for the record is the coldest run yet in GA for 4/12 and the coldest since 3/22 there. It has a light freeze all the way down to some of the N and W suburbs of Atlanta as well as upper 30s to south of the Columbus-Macon-Augusta corridor and low 40s to Savannah and Valdosta. Most of the non coastal Carolinas get down into the 30s then. I'm assuming this will end up as a too cold run by at least several degrees, at least in GA since it is the coldest yet there and it is way out at day 10, but the signal for the coldest in the SE since 3/22 is getting stronger and will be interesting to follow. Edit: At 12Z on 4/12, this run is the coldest yet at 850 mb with -10C down to the NC/VA border and 0C down to just below Jacksonville. These are some 14-16 C BN in much of the SE. Edit: 12Z GFS is nowhere near as cold as 6Z in GA (as much as 11 warmer) and not as cold anywhere in the SE on 4/12. Not surprising due to how cold was the 6Z Edit: After 13 GFS runs in a row with a cold shot during 4/11-13, the 0Z 4/3 run says, "what cold shot?". Wow!

Based on the last couple of days of model runs, here are some thoughts: - Warm 4/4-6 in SE - Masters/CAD areas: warmest day of tournament Thu; much cooler due to CAD is becoming more likely Fri-Sat; looks like a wet tourney as every day has threat of rain, especially Fri-Sat - More speculative because further out but subsequent Canadian high probably brings in BN/dry period 4/11-13. Frosts possible (mid to upper 30s especially northern areas??), especially northern areas on 4/13. Coldest lows of the month to date in much of SE are being hinted at for 4/12-13, but nothing out of the ordinary for a decent mid April Canadian high. No freezes indicated outside of mountains.

These El Niño winters that quickly followed La Nina were significantly colder in the SE US than the prior winter: 1876-7 (cold), 1880-1 (cold), 1904-5 (very cold), 1911-2 (cold), 1925-6 (normal), 1939-40 (very cold), 1957-8 (cold), 1965-6 (cold), 1972-3 (normal), 1976-7 (very cold), 2009-10 (very cold) These weren't: - 1887-8 was slightly warmer than 1886-7 and near normal - 1918-9 was much warmer than 1917-8 and was near normal. It followed the very cold 1917-8, which was one of the coldest La Niña winters on record - 2006-7 was warmer than 2005-6 and warmer than normal - 2018-9 was warmer than 2017-8 and warmer than normal --------- Tally: - 11 of 15 were significantly colder than the prior winter - 9 of 15 were cold to very cold - 4 of 15 were near normal - 2 of 15 were warmer than normal, two of the three most recent cases Conclusion: As one living in the SE who prefers a cold winter, I'd take my chances with El Niño this winter on a normal or colder winter based on the above history despite two of the three most recent cases being warmer than normal, which would keep from betting heavily on it. I certainly would prefer it over other ENSO! Keep in mind that four of these 15 were historically cold. Although this analysis is centered on the SE US, much of this can be used for other areas as well. That includes seeing which were the 15 El Niño winters since the late 1800s that quickly followed La Niña and analyzing those 15 winters for one's own region.

More on El Niños in the SE that quickly follow La Niñas: These El Niño winters that quickly followed La Nina were significantly colder in the SE US than the prior winter: 1876-7 (cold), 1880-1 (cold), 1904-5 (very cold), 1911-2 (cold), 1925-6 (normal), 1939-40 (very cold), 1957-8 (cold), 1965-6 (cold), 1972-3 (normal), 1976-7 (very cold), 2009-10 (very cold) These weren't: - 1887-8 was slightly warmer than 1886-7 and near normal - 1918-9 was much warmer than 1917-8 and was near normal. It followed the very cold 1917-8, which was one of the coldest La Niña winters on record - 2006-7 was warmer than 2005-6 and warmer than normal - 2018-9 was warmer than 2017-8 and warmer than normal --------- Tally: - 11 of 15 were significantly colder than the prior winter - 9 of 15 were cold to very cold - 4 of 15 were near normal - 2 of 15 were warmer than normal, 2 of the 3 most recent cases Conclusion: As one who prefers a cold winter, I'd take my chances with El Niño this winter on a normal or colder winter based on the above history despite two of the three most recent cases being warmer than normal, which would keep from betting heavily on it. I certainly would prefer it over other ENSO! Keep in mind that four of these 15 were historically cold.

I'm also expecting El Nino and I'd welcome it with open arms as they in the SE overall average a fair bit colder than La Niña and even somewhat colder than neutral due to the tendency for a higher PNA working in concert with a typically more active subtropical jet. This means that the stubborn SE ridge is usually weaker during El Niño. El Niño right after La Niña can really shake up the pattern and help lead to a much colder winter. Examples: 1904-5, 1911-2, 1939-40, 1957-8, 1965-6, 1972-3, 1976-7, and 2009-10. But we'll have to see about the SER as the near record warm western equatorial Pacific and strong AMO have been supporting it. The major El Niño forecasting failure year (including for me) of 2017 gives me pause and thus prevents me from getting overconfident about it returning. This was a post I made yesterday in the main ENSO thread: "Currently, 14 of 16 dynamic models (88%) are predicting an oncoming El Niño. How does this stack up to prior March predictions? I can see them going back to 2005 at the link below. That gives us a decent sample size of 19 years. - This March's 88% is 3rd highest of all 19 and 2nd highest of the 14 not already El Niño. That's strong support for an upcoming El Niño. - 2015 was at 94%, but that was already El Niño unlike now. Regardless, the models did very well in not only calling for El Niño to continue but for it to strengthen. - The other one at 94% was the already noted 2017, which turned out to be by far the worst failure of the 19 being that it ended up La Niña. - What % of models were predicting El Niño before other El Niños that materialized? - 2018: only 46% though it was still La Niña then making it challenging for the models. - 2014: 69%, a good job since ENSO was still cold neutral at the time - 2009: 60%, a good job since ENSO was still La Niña at the time - 2006: 67%, a good job since ENSO was still La Niña at the time So, this also reiterates that 2023 being up at 88% is strong support for El Niño. The main inconsistency is 2017. ----------------- Monthly ENSO model predictions back to 2005: https://iri.columbia.edu/our-expertise/climate/forecasts/enso/current/ "