raindancewx

CFS has an unusual look for June for the US temperature profile. Not common in El Nino from some quick looks. I was able to get a decent match by warming up a blend of 1963, 1992, with -2018 added in. Ignore the color template scale - just pretend its -7 to +7 - I made the blend much warmer. The actual pattern is essentially a -3 to +3 look. I do intend to list the analog model I use for global conditions for purchase or at least download somewhere. Since I have annualized solar conditions there for July-June, I'm going to wait until June is over before I release it.

I've been thinking about listing my analog model online for purchase online. Would any of you be interested? You basically type in your expected winter outcomes on seven global variables. Then all years back to 1931 are scored based on a weighted statistical model I developed off of a multi-factor polynomial regression. The scoring is then sortable, and I have a listing of what each variable corresponds to over the long-term (rain, snow, temps, etc in winter). Since ENSO is important but not dominant in the model, you can get strong scoring matches for ENSO years that are not in the same third of the scale (i.e. a rogue La Nina or Neutral might match this year) in special circumstances. Usually there are one or two odd ducklings in the seven variable set. So I pick a fixer year among the medium-level match years to bring the pack to the point of mimicking actual global conditions. The main purpose of the tool is to systematically score years as similar or dissimilar without needing to run through hundreds of maps manually. Knowing the most dissimilar years can actually be useful too, to see if reversing the exact opposite years produces similar matches to the most similar years. The objective scoring last year had both 1984 and 2016 as strong matches as an example. Pretty cold and severely wet winters in the West, just like we actually saw. 1995 was in there as among the least similar La Ninas, which is part of why I was pretty bullish on a shitty season for snow for most of you in the Northeast.

My current working blend for Summer, at least for precipitation is May 1972/1997. I think maybe 1972/2012 is better for temperatures, but haven't really looked at that yet. Here is that blend in May v. May 2023 to date. You can see the wet spots are similar running up the front range, NE, and in the SW, with the dry spots similarly placed too. Keep in mind, I'm incorporating this verifying in some form by month end -

I don't think anyone is actually dumb enough to forecast seasonally just based on ENSO. I have a seven factor method for seasonal stuff nationally. Then once the general idea is determined, I try to narrow it on the monthly patterns. But that's much harder. The atmospheric river thing in La Nina is not really new though either. The Great Flood of 1862 in the West was not an El Nino as an example. These are not new patterns. https://en.wikipedia.org/wiki/Great_Flood_of_1862 Any of this sound familiar? The Great Flood of 1862 was the largest flood in the recorded history of California, Oregon, and Nevada, inundating the western United States and portions of British Columbia and Mexico. It was preceded by weeks of continuous rains and snows that began in Oregon in November 1861 and continued into January 1862. This was followed by a record amount of rain from January 9–12, and contributed to a flood that extended from the Columbia River southward in western Oregon, and through California to San Diego, and extended as far inland as Idaho in the Washington Territory, Nevada and Utah in the Utah Territory, and Arizona in the western New Mexico Territory. The event dumped an equivalent of 10 feet (3.0 m) of water in California, in the form of rain and snow, over a period of 43 days.[3][4] Immense snowfalls in the mountains of far western North America caused more flooding in Idaho, Arizona, New Mexico, as well as in Baja California and Sonora, Mexico the following spring and summer, as the snow melted. ...The weather pattern that caused this flood was not from an El Niño-type event, and from the existing Army and private weather records, it has been determined that the polar jet stream was to the north, as the Pacific Northwest experienced a mild rainy pattern for the first half of December 1861. In 2012, hydrologists and meteorologists concluded that the precipitation was likely caused by a series of atmospheric rivers that hit the Western United States along the entire West Coast, from Oregon to Southern California.[6] An atmospheric river is a wind-borne, deep layer of water vapor with origins in the tropics, extending from the surface to high altitudes, often above 10,000 feet, and concentrated into a relatively narrow band, typically about 400 to 600 kilometres (250 to 370 mi) wide, usually running ahead of a frontal boundary, or merging into it.[7][8] With the right dynamics in place to provide lift, an atmospheric river can produce astonishing amounts of precipitation, especially if it stalls over an area for any length of time. ...The floods followed a 20-year-long drought.[9] During November, prior to the flooding, Oregon had steady but heavier-than-normal rainfall, with heavier snow in the mountains.[10]: 76–83  Researchers believe the jet stream had slipped south, accompanied by freezing conditions reported at Oregon stations by December 25. Heavy rainfall began falling in California as the longwave trough moved south over the state, remaining there until the end of January 1862, causing precipitation to fall everywhere in the state for nearly 40 days. Eventually, the trough moved even further south, causing snow to fall in the Central Valley and surrounding mountain ranges (15 feet of snow in the Sierra Nevada).[11][12]

The Jamstec seems to have a lower peak than a lot of the other models. Also has the transition away from an east-based event in Fall. I've mentioned that as a fairly likely outcome. For now, my assumption is an early peak in Nino 3.4. Halloween, plus or minus 30 days. Slow weakening after. The 1972-73 event weakened quickly despite a very healthy peak. Part of that is just how many La Ninas surrounded it: 1970-71, 1971-72, 1973-74, 1974-75, 1975-76. Never really had much of a chance. We've had multiple multi-year warm ENSO year events recently. I don't buy three initializing El Nino events in a row lasting two years each initialization. The image showing Nino 3.4 falling below +0.5C by winter 2024-25 matches my expectations. But I'd expect to be on the low side of the envelope starting around Jan-Feb.

We're still running neck and neck with the great El Nino of 2017. Nino1+2 Nino3 Nino34 Nino4 Week SST SSTA SST SSTA SST SSTA SST SSTA 10MAY2017 25.3 0.7 27.7 0.4 28.3 0.4 28.9 0.2 10MAY2023 27.0 2.4 28.2 0.9 28.3 0.5 29.0 0.2 In all seriousness though, we're in May now. Nino 3.4 has never warmed more than 0.4C from May to DJF in any year since 1950. Here are the similar Jan-Apr Nino 3.4 years I listed awhile ago in May. 1957: 28.55C - we're running behind 1963: 27.63C - we're warmer 1972: 28.32C - continues to be dead on 1997: 28.58C - behind 2014: 28.25C - very close I'm increasingly convinced 28.0C for winter 3.4 (+1.5C v. 1951-2010) is the right ballpark rather than the 28.5C - 29.0C the models try to show. In the modern climate, Nino 3.4 averages around 27.9C in May and falls off by over 1.3C or so from May to Winter. So you essentially need the ONI (difference to average) to grow by over 1.3C to even offset the normal trend. If you use 2014 as an example, it fell off from 28.25C in May to 27.19C in DJF, which is pretty close to the normal 1.3C fall off. The 1997 event grew to 28.87C by DJF, one of the biggest gains ever, but only 0.3C. 1963 fell off by raw temps. 1972 was the same in May and DJF. 1957-58 cooled off 0.4C or so from May. I'd expect DJF to be around 0.4C less than whatever May finishes at in Nino 3.4, give or take 0.2C or 0.3C. We'll see though.

I'm always amused by the talk of ENSO losing effectiveness over time as a driving factor. The truth is, it was never particularly important as a driver of temperature for most of you. I talk about it, because it is actually important where I am. But it's not really relevant in the Northeast really. PDO is more predictive for temperatures by a country mile in the NE US. In the deserts, you get phenomena if you really look through the records. In the high/colder desert/steppe land, the increase in cloud cover, snow and rain is correlated to lowering highs much more than lows in El Nino. In the warmer deserts at higher lattitudes, this is also true, but the effect is much more pronounced in Spring when there is hardly any rain normally. In La Ninas, you tend to have colder nights in the deserts as the dry air is even drier. Also fewer than average cloudy nights. As an example, we had well over 110 lows 32F or colder for Oct-May 2023, most since 2009-10, and well above the 30-year average of 92. It was 21F as recently as early April with dew points near 0F. When I look at only El Nino years, the biggest y/y changes in Nino 3.4 account for anywhere from 0.25 - 0.55 r-squared for changes in winter highs in the high terrain of NM and also old Mexico, parts of AZ and TX.

Nino 1.2 leads changes in the PDO. For now I still like the PDO to be negative in the winter. But of course it's going to revert toward less negative conditions. I just noted it was third lowest in almost 100 years. It's not going to stay that severe. The entire north Pacific could warm. Without the cold tongue east of Japan, that's still a neutral or negative PDO. The PDO has a tendency to behave differently in the high-sun half of the year v. the low-sun half of the year anyway. It could easily flip very positive by winter, but won't be clear until October. The interesting thing with 1972-73 is it kept flipping positive/negative within the cold season. Part of why that's such an interesting winter. I generally think of Nino 4 as the immediate connection to the PDO. So Nino 1.2 eventually becomes Nino 4 / PDO changes because it has to spread out. But right now, Nino 4 is only slightly warm, with no immediate pressure from severe warming. The 2020-21, 2021-22, and 2022-23 winters saw very cold Nino 4 readings - coldest in over a decade at times - and so yes, the PDO went severely negative. 1972-11-01T00:00:00Z 0.26 1972-12-01T00:00:00Z -0.09 1973-01-01T00:00:00Z 0.18 1973-02-01T00:00:00Z -0.07 1973-03-01T00:00:00Z -0.32 1973-04-01T00:00:00Z -0.74

Nov-Apr PDO finished at -1.65 on the JISAO/Mantua index. That's third most negative back to 1931-32 for a Nov-Apr. These are your -1 to -2 PDO Nov-Apr years. 1971-72, 1948-49, 1961-62, 1949-50, 1990-91, 1970-71, 1975-76, 2008-09, 1950-51, 2011-12, 1973-74, 1956-57. Of those, 1971, 1990, 1975, 2008, 1950, 1956 turned into El Ninos. These are your "El Nino following major -PDO" years then. 1951-52, 1957-58, 1972-73, 1976-77, 1991-92, 2009-10. Actually not a bad match for April, which is a good sign. That blend is actually severely cold in most of the US in the Fall, but then it lets up December. Would be a pretty good winter in the Southern US, but not particularly cold anywhere in winter itself. There is some tendency for severe cold in the Fall in volcanic years - this might actually be a decent blend for now.

1995-96 is interesting as a near perfect anti-log, at least conceptually: - First full recovery from Pinatubo (2023 is still seeing volcanic distortions) - East-based La Nina (east based El Nino) - Positive PDO (Negative PDO) - Followed an El Nino (followed a La Nina) - Near solar minimum (near solar maximum) - Weak ENSO (strong ENSO)

One weird thing about this sequence is that the Modoki La Nina and traditional El Ninos often both favor the West for heavy snow. I wouldn't necessarily expect massively different snowfall patterns in a traditional El Nino - I'd look for good snows for a lot of the West, with fluky heavy snows in the South. I thought the NE would do alright for snow by Northern New England last year. But this year, you'd probably just see more fluky snows in the East generally. If you look at snow in the five years I listed (1997-98, 1991-92, 1972-73) minus (1957-58, 2014-15), it's likely quite similar. If we have a strong El Nino, that is traditional (not a Modoki and east based), with a -PDO, then the obvious years to subtract out are 2014-15 and 1957-58 which are super +PDO events and pretty snowy in the Northeast. The blend for this winter is going to need three unusual/rare components: - Huge warm up year over year in DJF (+2.0C y/y is doable - and very rare) - Volcanic winter - PDO & ENSO in opposite phases These are your "cold to warm" by +2C or greater warm up years for Nino 3.4 -

Conceptually, the Canadian look for winter is close to 1972-73, 1991-92, 1997-98 minus 1957-58, 2014-15. I did warm that blend up by 0.2C since it is centered on the mid-1980s. PDO, ENSO, and IOD are in the right phases, with the Atlantic/North Pacific not super far off. Big heat east of Japan, at 60E, 0N, El Nino centered at 120W, etc. The paper on the IOD has the right idea. I'm always a bit skeptical about the lead time, especially since the Indian Ocean seems to be warming faster than the other oceans. But the 14 month lead idea is consistent with an 11/2023 peak for this event.

I didn't run the absolute value calculation each year. But I suspect these are the closest Nino 3.4 transitions since 1950 for Jan-Apr to observations in 2023. 1957 26.04 26.54 27.46 28.23 28.55 28.36 28.17 27.69 27.44 27.42 27.62 27.90 1963 25.77 26.22 27.18 27.78 27.63 27.62 27.78 27.48 27.40 27.36 27.47 27.62 1972 25.62 26.30 27.09 27.89 28.32 28.18 28.14 27.95 27.95 28.26 28.61 28.69 1997 26.01 26.38 27.04 27.98 28.58 28.82 28.86 28.75 28.85 29.08 29.12 28.89 2014 26.05 26.14 27.00 27.90 28.25 27.96 27.23 26.82 27.01 27.16 27.46 27.31 Blend 25.90 26.32 27.15 27.96 2023 25.83 26.29 27.18 27.91 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 Those five years would be a pretty severe cold season, outside of a major warm up in January. November and March (kind of like this past year really) would likely be quite severe. The severe fall/spring should play out again in some form with the volcanic activity contributing to that. March 1973 and March 2015 have some really cold storms in the West super far south, with snow down to the suburbs of Guadalajara in March 2015, and historic late season snows throughout New Mexico in 1973. The DJF blend of the five is: 1957-58 (28.15C, +1.65C against 60-year means in DJF in Nino 3.4) 1963-64 (27.36C, +0.86C) 1972-73 (28.33C, +1.83C) 1997-98 (28.87C, +2.37C) 2014-15 (27.18C, +0.68C) Blend: (27.98C +1.48C)

It's been tough finding good matches at this time of year with the SST configuration. But 1972/2012 as a blend has been decent for the main ENSO zones. That's basically a cooler version of what the Canadian shows too, right? -PDO, core of the El Nino centered at 120W.

The great sort-of east-based El Nino of 2023-24. Up to date subsurface readings (Feb, Mar, Apr) for 100-180W, at 0-300m below the surface: 2023: +0.09 / +0.84 / +1.19 ------------------------------- 2014: +0.39 / +1.60 / +1.41 2018: -0.11 / +0.51 / +0.80 2018: -0.11 / +0.51 / +0.80 ------------------------------- Blend: +0.06 / +0.87 / +1.00 Not a lot of similar years for this Feb-Apr for the subsurface progression. Actual weather in May is forecast to be much colder than that blend too. April 1997, 2014, 2015 are the only Aprils since 1979 with a warmer subsurface for 100-180W than April 2023. The cold waters at depth in the 100-180W zone, on the west side of the image, imply an early peak and then steady weakening after the Fall - but we'll see. I don't really have an issue with this getting pretty healthy for a while. Not sold on it lasting through winter though at anything near historical strength though.

The big eruption by Kamchatka recently, Shiveluch, also happened in 1957. Wikipedia has it as a VEI 5 for 2023. I suspect it will enhance the upper level cold any +WPO lows have by Kamchatka. There has been rapid cooling of the ocean near Kamchatka since the eruption, presumably in part due to the aerosol effect from the ~200,000 tons of SO4 released into the air. Really stands out with the warm tongue from the -PDO still running east of Japan. More impressive solar weather recently. Some of the "volcanic" El Ninos also are high solar, which is nice. The high solar El Ninos are 1939-40, 1957-58, 1968-69, 1972-73, 1982-83, 1991-92, 2002-03, 2014-15 among the El Nino initiation group. 1982, 1991, followed major volcanic activity. Another visible night of the Aurora Borealis over New Mexico.

Nino1+2 Nino3 Nino34 Nino4 Week SST SSTA SST SSTA SST SSTA SST SSTA 19APR2023 28.0 2.5 28.2 0.6 28.1 0.3 28.8 0.3 19APR2017 26.2 0.7 28.1 0.6 28.3 0.5 28.7 0.2 We've almost caught up to the great 2017 El Nino...

One thing I'm researching is the best Western snow-pack years in a La Nina to El Nino transition. The level of snow out here is still stupid amazing. We've just about exited Rio Grande Compact restrictions locally with 400,000+ acre feet of water already, even with the mountain snow by the Rio Grande headwaters yet to melt. We're still not really seeing the typical warm Nino 1.2 response in old Mexico yet. Although the wet April in the highlands of Mexico is consistent with the -PDO. I guess you could make the case the places closer to Chiapas are seeing the more conventional (dry) response from a warm Nino 1.2 (look at 90-95W, 16-18N)

Nate is retiring from doing the PDO stuff, but he sent me this awhile ago, along with some other people - I removed his contact info. You guys are jumping the gun on the El Nino strength stuff. Just wait til May. You almost never get Nino 3.4 warmer than May in the following winter - and it's never been more 0.4C warmer. It's not some great mystery why the predictability barrier ends in late Spring. I will no longer be providing PDO index updates. You can get monthly updates for PDO index values based on NOAA's Extended Reconstructed SST (ERSST Version 5) from NOAA's Climate Prediction Center: https://www.cpc.ncep.noaa.gov/products/GODAS/multiora/index/mnth.ersstv5.clim19912020.pdo_current.txt Access to more information about the PDO, including updated graphics, is available from NOAA's Physical Sciences Lab: https://psl.noaa.gov/pdo/ best wishes, Nate ~~~~~~~~~~~~ Nate Mantua NOAA/NMFS Southwest Fisheries Science Center Santa Cruz, CA

The different PDO indexes use slightly different input and formulas for the calculations. I like the Nate Mantua index more because it has considerations regarding biological observations. It's kind of like how the Koppen classification was designed to explain why plant life and animal life changes in certain environments over very small areas. Hitting 90F in NYC at least a month earlier than the 100-year average (5/29) is a good sign for an El Nino historically. Most of the following winters have fierce cold snaps for large areas of the US. We're right between 1977/2002 with the 90F today. 2010 04-07 (2010) 92 09-08 (2010) 90 153 1991 04-08 (1991) 90 09-17 (1991) 93 161 1977 04-12 (1977) 90 09-03 (1977) 90 143 2002 04-16 (2002) 92 09-10 (2002) 90 146 1976 04-17 (1976) 91 08-23 (1976) 90 127 2009 04-26 (2009) 92 08-19 (2009) 90 114 1962 04-27 (1962) 91 08-20 (1962) 91 114 1990 04-27 (1990) 91 08-27 (1990) 90 121

Here is a better way to look at what I was saying. Look at the temperature grid v. the snowfall pattern nationally. The lightest green area is 55-60F average annual temperature. The lighter greens for snow are generally in the same spots.

Anti-logs will be pretty useful again this winter to correct for the unusual-ness of the event. There are quite a few recent La Ninas with +PDO setups - I suspect a few of them will show as useful opposites later on. There are a couple years on the old data sets in the 1930s/1940s where Nino 1.2 gets real warm, for a sustained period, but it never really spreads out (-PDO, super warm 1.2 look)

Also, the Jamstec has an east-central El Nino with a -PDO look.

The Shiveluch volcano that is erupting now has sent ash 12 miles up into the atmosphere. Interestingly, for those of you who like 1957 as an analog, there was also a major eruption that year. Also 1854. The winters of 1957-58 and 1854-55 are both pretty severe. I'd say for New Mexico and Colorado the three most severe winters since 1800 are 1854-55, 1914-15, and 1972-73. I would think a lot of the ongoing gains in +WPO setups/strength has been tied to this volcano semi-continuously erupting and shooting ash up over Kamchatka. https://en.wikipedia.org/wiki/Shiveluch March 1958 is another crazy month - doubt we reach that level of severity though.

What a stupidly amazing month March was -