GaWx

2 hours ago, NorthHillsWx said:

We have eclipsed 90 for the third straight day at my house 

Back to back 90+ at KSAV with 3rd so far this spring. Today’s was a doozy at 93!

Great news on today’s EW for short term drought relief 4/27-5/3:

Yesterday’s run:

 

Today’s run is even wetter:

1 hour ago, snowman19 said:

 

Keep in mind that these are straight 1991-2020 anomalies rather than RONI equivalent anomalies that are relative to warm average global tropical anomalies. So, there’d still be some blue if that were the case being that there’s ~0.5C diff.

42 minutes ago, snowman19 said:

Subsurface anomalies over +5C showing up:
 

The 5+ is centered pretty far west (140-160 W, which is west central 3.4. Hoping that’s a sign that El Niño will be center to west based like Cansips suggests and not east based like NMME shows.

50 minutes ago, jconsor said:

University of Arizona has a bold forecast, much more active than other forecasts to date: 9 hurricanes and 4 majors with an ACE of 155.  Their model is based on machine learning initialized with ECMWF seasonal forecast SSTs.  They cite forecast significantly above normal tropical Atlantic SSTs as the main factor.  News release:
https://has.arizona.edu/news/forecast-2026-hurricane-activities-over-north-atlantic

More technical summary:
https://has.arizona.edu/sites/default/files/2026-04/April-2026-Tropical-Cyclone-Forecast.pdf

Seasonal hurricane predictions that have been issued so far:
https://seasonalhurricanepredictions.bsc.es/forecast/seasonal-prediction

Univ. of Arizona has a very good track record.  They started issuing Apr outlooks in 2022.  Their Jun forecasts were notably higher than almost all others in 2017, 2019 and 2023 and ended up verifying well (In Jun 2017 they forecast 181 ACE and actual was 225, while most other outlooks were in the 100-130 range).  In Jun 2019 they forecast 151 ACE and actual was 132, while most other outlooks were in the 80-105 range.  In Apr 2023, they forecast 163 ACE and actual was 148, while most other outlooks were in the 90-130 range).  Notice that all 3 years had El Nino conditions at the time of forecast initialization and the Nino was forecast to strengthen - but in 2017 and 2019 that strengthening failed to occur and in 2023 the Nino ended up weaker than many models had forecast and while it limited Atlantic activity to a degree, it was less impactful than expected.

In 2022, 2024 and 2025 their Apr outlooks were notably lower than almost all others (In 2022 UA forecast 129 ACE and actual was 96, while almost all other outlooks were in the 150-190 range. In 2024, they forecast 156 ACE and actual was 162, with almost all other outlooks in the 185-230 range.  In 2025, they forecast 110 ACE and actual was 133, with most other outlooks in the 145-190 range.) 

You can download all of the historical hurricane season prediction data for past years from the Univ of Barcelona site linked above.

Personally I would go with an ACE range of 80-130 right now.  Main reason is I believe the standing wave of low-level westerlies over the eastern Atlantic and west Africa will help lead to an Atlantic Nino, energize the W. African monsoon (WAM) and lead to an active wave train, while as we know El Nino influence on shear is mainly west of 60W.  Also, the persistent very warm SST anomalies in the NW Pacific from E of Japan to S of AK and the SW Pacific east of AU/NZ (e.g. negative IPO) along with the above-mentioned Atlantic Nino and African standing wave would likely lead to resistance toward WWBs reaching the eastern Pacific (with the focus remaining near the dateline).  This would tend to shift the Walker circulation west of a typical moderate to strong Nino.

I think there's a 55% chance RONI stays below strong Nino levels through Aug-Oct.  Not ruling out a strong Nino, but I think a super Nino RONI-wise is unlikely (<15%) through Aug-Oct. 

My main analog years are 1951, 1963, 1969, 2006, 2015, and 2018, with more emphasis on the first three given the strong WAM that prevailed.

Thanks, Yaakov. Hoping the AZ forecast busts way too high as I’d like a quieter ACE for a change.

1 hour ago, LakePaste25 said:

 

 

 Based on the above maps for Jan, I’m going to consider renting a place in Anniston, AL, just for that month. 

2 hours ago, olafminesaw said:

 I’m targeting November for the change to consistently wetter than normal in much of the SE, which is typical for strong El Niño autumns. Until then lots of watering is anticipated during dry periods.

 But good news is that for well before then, the model consensus is showing a pattern change to wetter than normal in ~10 days and going into early May in my general area, where the drought is the worst in the SE. Fingers crossed that from then through Oct will be closer to normal overall.

Latest Euro Weeklies for Apr 27-May 3:

2 hours ago, GaWx said:

 

1. March ‘26 QBO: I just emailed the PSL

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”

23 hours ago, GaWx said:

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.

 

 

29 minutes ago, snowman19 said:

 

 

 

 

 

 

 

 

 

 

 

 

 

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

31 minutes ago, TheClimateChanger said:

Incredible! Downloaded data from SERCC (observations from March 1-April 14, forecast values through April 19) reveals nearly 80 long-term threaded stations are in the midst of their warmest spring on record, calculated by average daily high temperature. Led by Huntington, West Virginia, where the first 50 days of spring has seen a mean high temperature of 72.8F, an astounding 12.1F above the 1991-2020 mean. Again, that's a 50-day average!

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.

14 minutes ago, TheClimateChanger said:

 

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):

2 hours ago, Typhoon Tip said:

His linear, arithmetic approach to the question is not how nature works. 

He doesn't appear even aware of "synergy" in the system, emergent properties of complex systems that are wholly dependent upon the interactions of products, that cannot be very coherently pre- assessed or predicted because they do not exist until they are manufactured by the system.  

A+B -->  A'         C+D --> C'          ;       A' + C'   -->   A''       where A'' is the synergistic bi-product.

If we really wanna roll sleeves in how nature works, A, B, C, and D, are all partial derivatives occurring in time - it's really more like

d(A)+d(B) -->  A'         d(C)+d(D) --> C'          ;       d(A') + d(C')   -->   A''

We've been talking about this for years at this point in here.   The increased frequency of 'extra special' heat waves, Globally, surpassing all predictive tools ( sometimes by very large margins ), have already been denoted as "synergistic heat waves" in various climate publications/among the compendium of accredited sources.   

There's probably going to need some discrete reanalytic study, but it's much more likely that the heat in the SW U.S. during March was a phenomenon of this ilk.  

 

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:

 

18 hours ago, snowman19 said:

 

 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.

1 hour ago, mitchnick said:

Weekly SSTA (just updated) for Enso 3.4 and 4 have been stuck at +.2C and +.6C respectively for the past 3 weeks. Looking forward to a month from now since we're still in a Niña hangover of sorts that should be wiped out by then.

https://www.cpc.ncep.noaa.gov/data/indices/wksst9120.for

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:

1 hour ago, snowman19 said:

 

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.

3 hours ago, bluewave said:

Great write up from ECMWF on how to interpret the recent El Nino forecast so early in the development process.

https://www.ecmwf.int/en/about/media-centre/science-blog/2026/el-nino-2026

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: