GaWx

I got a quick email reply, but it contains bad news regarding getting QBO updates: “Hi The QBO we have is produced using the NCEP/NCAR Reanalysis which has ended production. We are trying to determine how we will compute this time series. See https://psl.noaa.gov/news/2026/r1datanotice.html Cathy S. Your PSL Data Team”

1. March ‘26 QBO: I just emailed the PSL 2. More on the 3.4 warming: these are straight rather than relative +0.531 for latest OISST, a rise from +0.15 just 4 days ago and implies a RONI having risen back to just above 0.0. Thus despite this rise, I still see almost no way April will average up at +0.6 for RONI, which is what BoM is forecasting: Latest CDAS, which has a cold bias: +0.25 vs ~0 just 2 days ago

The EWs have cooled considerably for Apr 20-26 in the NE vs 5 days ago: 5 days ago: mild NE Today’s: cool NE

Have you changed from the “Global Warmer” to the “US Warmer”? The US has only 2% of the world’s surface area and only 6% of the world’s land surface area and that’s including Alaska. This is the same argument used against those talking about how hot the US was in the 1930s summers.

Do you have Canada by chance?

It’s the 15th and still no March QBO has been released. What in the wide, wide world of sports is going on? It never has taken more than a few days into the new month to release it.

Nino 3.4 SSTa levels have finally started rising during the last 2 days, a 0.2C increase. Often there’s a delayed response to strong -SOI levels as they usually don’t produce SST rises immediately (reminder: these are straight rather than relative but the point is the rise):

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