GaWx

Tip, Thanks for your reply. We know that the Arctic has warmed considerably more than middle latitudes, especially in winter. Thus, the contrast between the avg Arctic temp. and the avg mid latitude temp has lowered, which has reduced the avg speed of the polar jet. Thus per the source noted below: “A slower and more contorted jet stream allows cold air to move further south and warm air to move further north, and it also allows weather systems to persist longer than usual. Under these circumstances, episodes of severe cold or protracted heat, as the UK experienced in spring and summer 2018 respectively, become more likely.” https://theconversation.com/arctic-breakdown-what-climate-change-in-the-far-north-means-for-the-rest-of-us-123309#:~:text=The exceptional rate of Arctic ( the,and determines the paths of weather systems. But I still have to wonder if this phenomenon along with the up to 3F warmer globe were strong enough factors on their own to result in the W US heatwave being a record producer or would it without CC still have been a record producer but just at a lower level? I don’t see how this can be proven one way or the other. With the extreme heat so much hotter than the prior record, that would be quite the feat for CC’s influence. So, I’m at least for now maintaining what I said on April 3rd: “had there been no GW the US still could have had their warmest month since the late 1970s but with not as warm temps.” All I said on April 3rd was “could”. After all, one would have to prove that it “could not” to conclude that I’m wrong. Fair enough?

The final strat. warming occurred on April 9th, 13 days earlier than average: @snowman19

Does anyone disagree with what Chris Martz says here? He says that a record hot W US March would still have occurred had there been no GW because that elevates the starting temperature by no more than about 3F whereas records were smashed by 10-20F. So, this heat wave would still have been unprecedented in the records in scope. It just wouldn’t have been quite as hot, which is consistent with my thinking. I essentially already had said all of this ITT on April 3rd at this link: I’d like to add that the extreme cold over AK/W Canada and the record strong March +NAO were likely all associated with each other. Also, note that on a seasonal basis, cold/warm E US winters are often associated with warm/cold W US winters due to the opposite reaction idea. Also, a cold US winter is often associated with a warm Canadian winter. The W heat was caused by a record strong upper level ridge over the W US. But the ridge, itself, was associated with an atmospheric Rossby wave. Because of La Niña, there was low frequency convection over the W and C tropical Pacific. That caused a cyclonic circ. (deep low) to form over Hawaii. Downstream of that, a record strong ridge was pumped up over the W US:

So far as regards the effects on Nino 3.4 SSTa, it’s been all bark and little or no bite with it still at ~-0.2 to -0.3C. It should resume warming shortly, but it’s done none the last 3 weeks.

The latest official weekly for 3.4 was semi-stalled at -0.3 after being -0.2 the week before and -0.3 two weeks before: https://www.cpc.ncep.noaa.gov/data/indices/rel_wksst9120.txt

Latest 10 day CFSv2 ensemble mean forecast of RONI: +2.0 peak OND. Note that unlike the BoM’s nearly impossible +0.6 for April, this has a much more sensible -0.3:

The newest BoM prog (dated April 11th) is unchanged and thus still has a RONI of +0.6 for April averaged out. This is almost certainly going to end up much too warm for April: How do I know it is almost definitely going to bust much too warm for April? Weekly RONI equivalent: 3rd column is 3.4 01APR2026 0.6 -0.3 -0.2 0.3 08APR2026 1.0 -0.2 -0.3 0.2 https://www.cpc.ncep.noaa.gov/data/indices/rel_wksst9120.txt So, the weeks centered on April 1/April 8 were -0.2/-0.3. Here’s the current OISST, which isn’t relative and thus one needs to subtract ~0.5 from it: As the above chart shows, there’s been no net warming for the last 3 weeks and the latest few days of OISST have been only +0.05 to +0.15. Subtracting 0.5 gives ~-0.4 for the RONI equivalent. April 1-11 OISST are likely no warmer than ~-0.3 for RONI equiv. To be conservative in converting from OISST to ERSST, I’ll call it -0.2 for RONI MTD. The weeklies I showed suggest between -0.2 and -0.3. How is it even possible for April RONI as a whole to come in anywhere near as warm as +0.6? These daily OISST readings (don’t forget these are not relative) would need to skyrocket to an avg of at least ~+1.5 for Apr 12-30!! And with OISST starting off at <+0.2, there are going to have to be some +2++ dailies starting no later than 2 weeks from now! Nothing even remotely close to that extremely rapid rate of warming has occurred on record. Thus, BoM is looking to bust much too warm for Apr RONI. With Apr being way off, the credibility of the rest of the run is compromised.

QBO (30 mb) still has not updated for March! I don’t recall it ever taking nearly this long for any month, which has me a bit concerned: https://psl.noaa.gov/data/correlation/qbo.data

Latest OHC:

I’ll compare 2026 to others. Here’s 2026 with its first strong -SOI period not til days 98-102: 2026 98 1010.27 1010.30 -17.45 2026 99 1009.30 1011.45 -32.74 2026 100 1009.19 1011.45 -33.53 2026 101 1009.56 1011.00 -27.62 2026 102 1010.69 1010.75 -17.67 1) 1994: already had strong -SOI days 75-90: 1994 75 1009.95 1009.25 -16.33 1994 76 1011.21 1009.00 -9.08 1994 77 1010.30 1008.65 -11.78 1994 78 1009.25 1009.30 -19.92 1994 79 1009.33 1009.25 -19.32 1994 80 1010.65 1008.60 -9.86 1994 81 1011.61 1009.45 -9.32 1994 82 1012.00 1010.25 -11.30 1994 83 1010.73 1009.80 -15.23 1994 84 1009.74 1010.30 -22.37 1994 85 1011.13 1011.00 -19.08 1994 86 1012.49 1011.90 -16.86 1994 87 1012.66 1011.95 -16.27 1994 88 1012.31 1012.15 -18.90 1994 89 1012.79 1011.85 -15.19 1994 90 1012.12 1011.85 -18.36 2) 1997: already had strong -SOI days 81-90: 1997 81 1011.33 1011.55 -20.69 1997 82 1009.53 1010.25 -23.08 1997 83 1009.46 1010.35 -23.92 1997 84 1009.17 1010.95 -28.17 1997 85 1009.38 1011.65 -30.50 1997 86 1008.01 1011.85 -38.04 1997 87 1007.55 1011.15 -36.91 1997 88 1010.10 1010.60 -22.07 1997 89 1011.92 1011.00 -15.24 1997 90 1011.97 1010.55 -12.85 3) 2002: already had strong -SOI days 72-80 2002 72 1010.71 1012.50 -28.24 2002 73 1010.25 1011.40 -25.18 2002 74 1011.11 1011.10 -19.62 2002 75 1010.70 1010.90 -20.63 2002 76 1009.60 1010.35 -23.27 2002 77 1010.04 1010.55 -22.13 2002 78 1012.20 1010.55 -11.78 2002 79 1013.25 1010.20 -5.07 2002 80 1010.45 1008.90 -12.26 4) 2004: already had strong -SOI days 87-97 2004 87 1010.56 1010.65 -20.11 2004 88 1009.84 1011.25 -26.42 2004 89 1009.20 1011.25 -29.49 2004 90 1008.64 1011.75 -34.56 2004 91 1007.47 1011.75 -40.16 2004 92 1006.10 1012.30 -61.94 2004 93 1005.85 1012.25 -63.38 2004 94 1006.74 1011.55 -51.92 2004 95 1005.93 1011.20 -55.23 2004 96 1007.71 1011.00 -40.96 2004 97 1008.59 1010.60 -31.73 5) 2014: already had strong -SOI days 73-80 2014 73 1010.53 1009.55 -14.98 2014 74 1009.38 1010.70 -25.99 2014 75 1008.55 1009.75 -25.42 2014 76 1009.09 1010.40 -25.94 2014 77 1009.21 1009.75 -22.26 2014 78 1007.89 1010.20 -30.73 2014 79 1007.49 1009.30 -28.34 2014 80 1009.69 1008.25 -12.78 6) 2015: already had strong -SOI days 67-79: 2015 67 1007.50 1008.10 -22.55 2015 68 1008.11 1008.65 -22.26 2015 69 1008.73 1008.20 -17.14 2015 70 1009.33 1008.65 -16.42 2015 71 1009.24 1008.45 -15.89 2015 72 1009.91 1007.55 -8.38 2015 73 1010.42 1007.65 -6.42 2015 74 1010.41 1008.90 -12.45 2015 75 1006.90 1010.15 -35.23 2015 76 1005.66 1009.05 -35.90 2015 77 1008.13 1008.65 -22.16 2015 78 1010.35 1009.55 -15.84 2015 79 1008.79 1011.20 -31.21 7) Even the non-Nino 2012, which psyched out the Euro, had an earlier strong negative period: 2012 90 1011.39 1009.80 -12.06 2012 91 1009.90 1010.70 -23.50 2012 92 1010.45 1011.70 -26.25 2012 93 1012.60 1012.20 -14.35 2012 94 1012.53 1013.55 -24.59 2012 95 1011.19 1013.45 -33.53 2012 96 1010.10 1012.15 -32.01 2012 97 1009.94 1011.85 -31.01 2012 98 1009.98 1011.60 -28.91 2012 99 1010.16 1011.65 -27.98 2012 100 1011.50 1011.45 -16.87 OTOH, 2026’s strong -SOI is ahead of 2006, 2009, 2018, and 2023.

Chris, 1. The writeup you linked us to specifies what we already knew: the U.S. now incorporates RONI for its official ENSO updates vs the Euro still not doing so. So, to approximate RONI based on the current difference, ~0.5C should be subtracted from the Euro progs since they are still predicting a straight ONI. 2. The following shows that although the Euro’s too warm ASO ONI prog was highest for April progs in 2017 (+1.4), it was also significantly too warm in 2025 (+0.8), 2022 (+0.7), 2021 (+0.6), 2020 (+0.8), 2014 (+1.2), and 2012 (+0.6). Moreover, misses to the cold side were much less frequent and smaller. So, based on averaging out the misses, a notable warm bias is evident although it isn’t as large when El Niño actually verifies. None of this means ONI will definitely verify colder than the April Euro prog, but rather to not be surprised if it verifies several tenths colder based on a bias corrected ONI prog:

Today from JB: any comments? Is he making sense saying that in the cold season it’s harder to get record cold further N?? That doesn’t sound right. What am I missing? Aren’t SDs/variances larger at higher latitudes? See what I bolded below. OTOH, due to GW, if he had said it’s harder to get record cold than record heat, I’d agree. So, in that regard, much of AK/Canada having its coldest March on record in this 2-3F warmer world certainly is quite remarkable. From JB: Comment on the March Hype Wave “Yes it was a heat wave and for the US in March it was unprecedented in times of reliable records But countering it was Canada and especially Alaska which was brutally cold This winter (2025-26) was the coldest on record in Fairbanks, surpassing the previous record set in 1965-66. Now think about this as far as the greater deviation The colder it gets, the harder it is to get colder in the cold season. If you have an extremely cold place, and Fairbanks is a longstanding site. So this is remarkable. The deviation from normal both high and low in NAMER was about the same. But at lower temperatures its easier to get it that much warmer than it is at colder temps. So the cold in Canada was more impressive than the warmth in the US as far as competing against the averages, if one is considering the fact that in cold areas in their cold season, its harder to get it that cold over a 30 day period” However, later he says this, which I agree with since variances in summer are not as large as March: “Now lets look at the March map again off the PSL site. you have got areas 12 above normal in the time of the year when its much easier to get that warm, then when you are at the hottest time of the year, pulling this off like 1934,1936 is much harder to do.” ——————— PHX was 6.5 warmer than any other Mar on record whereas Fairbanks was only 2.4 colder than any other Mar on record. But, 2.4 colder in a warmer world might be about as impressive. Opinions?

My water bills are looking to be outrageously high, but I have no choice if I want to keep the grass healthy.

UKMET has been one of the better models in recent years. It’s going ~+2.05 for Sep ONI and would likely rise a few more tenths from there. Then take off ~0.5 to convert to RONI. So, ~+1.5-1.6 C RONI in Sept and rising per UKMET. Euro ONI is just over +2.2 in Sept and rising, but it has tended to verify too warm although not as much warm bias verified on average in actual El Niños. This all suggests to me a mid to high grade strong RONI peak as of now. I’ll continue to update.

That’s the coldest March for Canada, overall, since 2002, which is below: