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Great post. And welcome to AmericanWx. I'll add some commentary of my own. The Charney sensitivity is most closely related to the fast-feedback equilibrium climate sensitivity (ECS). It is important to note that slow-feedbacks are often omitted from the ECS estimates you often see. Generally speaking fast-feedbacks are those that complete in < 150 years. Slow-feedbacks include those that longer than 150 years to complete like would be the case for Greenland and Antarctic ice sheets and some carbon cycle processes. Sherwood 2020 - An Assessment of Earth's Climate Sensitivity Using Multiple Lines of Evidence is great comprehensive study that I suspect will be referenced heavily by AR6. The 1-sigma and 2-sigma envelopes for 2xCO2 is 2.6 - 3.9C and 2.3 - 4.7C respectively. Official Link: https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019RG000678 Free Copy: https://climateextremes.org.au/wp-content/uploads/2020/07/WCRP_ECS_Final_manuscript_2019RG000678R_FINAL_200720.pdf

Does Koonin present a model of the climate system in his book that makes predictions from 1880-present that are better than say CMIP5 or CMIP6? General relativity and quantum mechanics disagree by 120 orders of magnitude regarding the cosmological constant. It is called the worst prediction in all of science. But I trust you still feel that GR and QM are settled enough to continue relying on GPS to get you where you need to go or on MRI to diagnose a potentially serious medical issue you might have in the future. No? Fine grained details regarding AGW are still heavily debated, but the fact that the planet is warming and that humans have played a significant role is about as settled as anything can get in science.

I didn't make the chart. Nick Stokes did. I'm guessing he downloaded the netcdf files and did a lot of manual stuff on his side. He also just mentioned something else last night...50 of the 68 members in Dr. Spencer's graph come from CanESM5 which runs very hot. It appears that KNMI does not yet have all of the CMIP6 data yet.

I'm really trying to be patient with Dr. Spencer. Afterall he and Dr. Christy did pioneer satellite measurements of tropospheric temperatures which is useful. But he just keeps posting misleading articles. http://www.drroyspencer.com/2021/04/an-earth-day-reminder-global-warming-is-only-50-of-what-models-predict/ Here he says the warming is only 50% what models predict. That's not true at all. This post is misleading at best because even though the graph is labeled as "Sea Surface Temperature" he's actually comparing observed SSTs with modeled air temperature. The problem...the atmosphere warms faster than the sea surface. Nick Stokes kindly created a graph in which observed SSTs are compared correctly with modeled SSTs. Note that "tas" is air temperature and "tos" is sea surface temperature. Is modeling perfect? Nope. Is it as bad as Dr. Spencer claims? Not even close.

JTWC estimated its minimum central pressure at 888mb. JMA at 895mb. This shatters the record for the most intense cyclone prior to May 1st and is in the elite top 20 highest wind speeds at any time of year. https://weather.com/storms/hurricane/news/2021-04-16-typhoon-surigae-philippines-forecast BTW...this was a well forecasted cyclone. Both the GFS and ECMWF had been consistently showing a low 900's intensity at least 5 days out.

The latest JMA advisory is 895mb.

Surigae is a beast. ADTv9 shows CI T# is 8.0 with estimated pressure of 890mb and winds of 170 kts. I've not been able to find the official 12Z pressure estimate yet, but JTWC is saying 155 kts. ADT90 LIST 02W.ODT CKZ=YES ===== ADT-Version 9.0 ===== ----Intensity--- -Tno Values-- --------Tno/CI Rules-------- -Temperature- Time MSLP/Vmax Fnl Adj Ini Cnstrnt Wkng Rpd ET ST Cntr Mean Scene EstRMW MW Storm Location Fix Date (UTC) CI (CKZ)/(kts) Tno Raw Raw Limit Flag Wkng Flag Flag Region Cloud Type (km) Score Lat Lon Mthd Sat VZA 2021APR17 054000 7.2 916.7 146.0 7.2 7.7 7.9 1.3T/6hr OFF OFF OFF OFF 10.69 -84.01 EYE 18 IR 97.0 11.36 -130.19 ARCHER HIM-8 18.1 2021APR17 061000 7.3 913.5 149.0 7.3 7.8 8.0 1.3T/6hr OFF OFF OFF OFF 16.61 -84.24 EYE 20 IR 97.0 11.35 -130.10 ARCHER HIM-8 18.1 2021APR17 064000 7.4 910.3 152.0 7.4 7.8 7.9 1.3T/6hr OFF OFF OFF OFF 14.37 -83.97 EYE 20 IR 97.0 11.43 -130.07 ARCHER HIM-8 18.2 2021APR17 070000 7.5 907.1 155.0 7.5 7.9 8.0 1.3T/6hr OFF OFF OFF OFF 18.17 -83.19 EYE 20 IR 97.0 11.55 -130.03 ARCHER HIM-8 18.4 2021APR17 074000 7.7 900.5 161.0 7.7 7.8 7.8 NO LIMIT OFF OFF OFF OFF 9.07 -83.17 EYE 18 IR 97.0 11.58 -129.95 ARCHER HIM-8 18.4 2021APR17 081000 7.8 897.2 164.0 7.8 7.9 8.0 3.2T/18hr OFF OFF OFF OFF 14.12 -83.98 EYE 18 IR 97.0 11.62 -129.81 ARCHER HIM-8 18.6 2021APR17 084000 7.8 897.2 164.0 7.8 7.9 8.0 3.2T/18hr OFF OFF OFF OFF 17.99 -84.15 EYE 18 IR 70.7 11.67 -129.78 ARCHER HIM-8 18.7 2021APR17 091000 7.8 897.2 164.0 7.8 7.9 7.9 NO LIMIT OFF OFF OFF OFF 10.49 -83.78 EYE 19 IR 70.7 11.74 -129.72 ARCHER HIM-8 18.8 2021APR17 094000 7.8 897.1 164.0 7.8 7.9 7.9 NO LIMIT OFF OFF OFF OFF 9.30 -84.51 EYE 21 IR 79.9 11.80 -129.67 ARCHER HIM-8 18.9 2021APR17 101000 7.9 893.7 167.0 7.9 8.0 8.0 NO LIMIT OFF OFF OFF OFF 16.97 -84.71 EYE 20 IR 79.9 11.87 -129.51 ARCHER HIM-8 19.0 2021APR17 104000 7.9 893.7 167.0 7.9 8.1 8.1 NO LIMIT OFF OFF OFF OFF 20.34 -84.85 EYE 20 IR 79.9 11.87 -129.49 ARCHER HIM-8 19.1 2021APR17 111000 7.9 893.7 167.0 7.9 8.0 8.0 NO LIMIT OFF OFF OFF OFF 18.33 -84.50 EYE 20 IR 79.9 11.94 -129.38 ARCHER HIM-8 19.2 2021APR17 114000 7.9 893.7 167.0 7.9 7.9 7.9 NO LIMIT OFF OFF OFF OFF 8.16 -84.74 EYE 19 IR 79.9 12.03 -129.26 ARCHER HIM-8 19.4 2021APR17 121000 7.9 893.7 167.0 7.9 8.0 8.0 NO LIMIT OFF OFF OFF OFF 16.59 -84.31 EYE 19 IR 79.9 12.05 -129.10 ARCHER HIM-8 19.5 2021APR17 124000 8.0 890.3 170.0 8.0 8.1 8.1 NO LIMIT OFF OFF OFF OFF 20.18 -84.63 EYE 20 IR 79.9 12.04 -129.06 ARCHER HIM-8 19.5 2021APR17 131000 8.0 890.3 170.0 8.0 8.0 8.0 NO LIMIT OFF OFF OFF OFF 15.77 -84.25 EYE 18 IR 79.9 12.06 -129.05 ARCHER HIM-8 19.6 2021APR17 134000 8.0 890.3 170.0 8.0 8.0 8.0 NO LIMIT OFF OFF OFF OFF 16.61 -84.06 EYE 18 IR 79.9 12.13 -128.98 ARCHER HIM-8 19.7 2021APR17 141000 8.0 890.3 170.0 8.0 8.0 8.0 NO LIMIT OFF OFF OFF OFF 19.79 -84.06 EYE 18 IR 79.9 12.16 -128.91 ARCHER HIM-8 19.8 2021APR17 143000 8.0 890.3 170.0 8.0 8.0 8.0 NO LIMIT OFF OFF OFF OFF 20.34 -83.52 EYE 18 IR 79.9 12.20 -128.87 ARCHER HIM-8 19.8

So the big question...will the IPCC AR6 stick with the likely ECS of 1.5-4.5C or refine it? Sherwood 2020's 1σ range is 2.6-3.9C and 2σ range is 2.3-4.7C. The IPCC uses 66% as the standard for "likely". Using this standard with Sherwood 2020 an argument could be made for 2.5-4.0C. That would be a big change. I'm wondering if 2.0-4.0C might be a more reasonable choice for now. With each passing decade we can constrain the lower bound further. I think at this point 1.5C is all but impossible at this point.

Sherwood 2020: An Assessment of Earth's Climate Sensitivity Using Multiple Lines of Evidence (official / free) suggests a TCR of 1.8C with 66% upper bound of 2.2C. If the PDF was normally distributed that would imply a 95% upper bound of 2.6C. However, the PDF is not normally distributed and has a long tail on the right side so 95% upper bound is likely higher than 2.6C. Sherwood 2020 is probably the most comprehensive study on climate sensitivity to date.

Some of you probably saw news articles regarding the Kramer et al 2021 publication which for the first time measures the net instantaneous radiative force using CERES and AIRS between 2003 and 2018. News Article: https://www.ecowatch.com/greenhouse-effect-nasa-study-2651319284.html Official: https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2020GL091585 Free: https://www.essoar.org/doi/10.1002/essoar.10506610.1 From the publication... Total-IRF = +0.033 W/m2/year +/- 0.007 LW-IRF = +0.027 W/m2/year +/- 0.006 SW-IRF = +0.006 W/m2/year +/- 0.003 The SOCRATES radiative transfer model predicts LW-IRF to be +0.023 W/m2/year +/- 0.003. The model computes the RF for increases in most of the GHG species found in the atmosphere. Note that measurement and modeling are consistent here. The MERRA reanalysis attributes +0.006 W/m2/year +/- 0.003 to aerosol declines. Note that this matches well with the measured value. The integrated IRF for 2003-2018 is +0.53 W/m^2 +/ 0.11 with 0.40 W/m^2 +/- 0.1 being in the LW band. Modeling predicted the LW band to be 0.35 W/m^2 +/- 0.05 over this same period which implies good agreement between theory and observation. In summary about 80% of the net heat uptake for the period 2003-2018 is the result of GHGs while 20% is the result of aerosol reductions. It used to be that aerosols were increasing which was suppressing the warming. They stabilized around 1980. But at least for this 15 year period efforts to reduce pollution are now contributing to the warming. This may explain why the EEI has increased to +0.87 W/m^2 +/- 0.12 (Schuckmann 2020) in recent years.

I could see it making a run at the low 1060's. :But I'll be extremely surprised if it hits 1070mb. There is going to be a pretty steep pressure gradient either way. The Euro actually shows slightly higher sustained winds than does the GFS even though it is much weaker with the anti-cyclone. It certainly looks like Fram export will be in high gear shortly.

There is no holding back by the GFS. The 12Z cycle is now showing a 1096mb high against a 971mb low.

https://nsidc.org/arcticseaicenews/2021/03/arctic-sea-ice-reaches-uneventful-maximum/ "On March 21, 2021, Arctic sea ice likely reached its maximum extent for the year, at 14.77 million square kilometers (5.70 million square miles), tying for the seventh lowest extent in the satellite record with 2007. This year’s maximum extent is 870,000 square kilometers (336,000 square miles) below the 1981 to 2010 average maximum of 15.64 million square kilometers (6.04 million square miles) and 360,000 square kilometers (139,000 square miles) above the lowest maximum of 14.41 million square kilometers (5.56 million square miles) set on March 7, 2017. Prior to 2019, the four lowest maximum extents occurred from 2015 to 2018."

It looks like there may have been a mesoscale boundary south of the storm that was forcing junk convection. It looks like the cell is starting outrun that now. Once it finishes ingesting this last bit of convection it looks like the inflow notch might clear out. We'll see what happens.

The spatial and temporal size of the 90 tornado ingredients contour from the 9Z SREF has doubled since last night. I'm pretty sure we've seen larger in the past, but this is high risk worthy for sure.

21Z SREF tornado ingredients product is somewhat aggressive. We've certainly seen larger spatial and temporal sizes of the 90 contour, but this one is respectable nonetheless.

In addition we had this publication come out last year with a comprehensive analysis of the Earth Energy Imbalance. It is now up to +0.87 W/m^2. https://essd.copernicus.org/articles/12/2013/2020/essd-12-2013-2020.pdf

We've seen 3 local peaks. One on Feb 15th, one on Mar 6, and the most recent on Mar 12 with a 5D average of 14.75 per NSIDC extent. We cannot eliminate the possibility of a higher max (the 2012 max occurred on Mar 20), but with each passing day the probability decreases. It looks to me like the melt season is going to start lower than it did last year.

Copernicus reports that February 2021 was coolest since 2014. https://climate.copernicus.eu/surface-air-temperature-february-2021

JAXA data showed a pretty significant surge the last few days which puts Mar 2nd above the mid Feb peak. The winter max will almost certainly occur in Mar per NSIDC as well.

Here is the NSIDC's update regarding the sea ice data problems. https://nsidc.org/arcticseaicenews/2021/03/nsidc-continues-to-investigate-sea-ice-processing-errors/

Oh...you're right. Between both Chrome and Edge cutting off support for ftp and having to switch to WinSCP to download the data I didn't even notice that it hadn't updated.

I usually just go to NSIDC directly. https://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/ I did see that glitch on that site earlier today. I was assuming the glitch was isolated to that site. The data on the NSIDC site looks good.

We've seen a pretty substantial decline in the NSIDC sea ice extent the last few days. The last time the winter max occurred in February was 2015. So there is recent precedent.

We cannot eliminate the possibility that we've seen the winter max for 2021.