GaWx

Thanks for posting this. In case there’s any confusion, here are some quotes from this: the Sun has reached its solar maximum period, which could continue for the next year. “This announcement doesn’t mean that this is the peak of solar activity we’ll see this solar cycle,” said Elsayed Talaat, director of space weather operations at NOAA. “While the Sun has reached the solar maximum period, the month that solar activity peaks on the Sun will not be identified for months or years.” Scientists will not be able to determine the exact peak of this solar maximum period for many months because it’s only identifiable after they’ve tracked a consistent decline in solar activity after that peak.

But -ironically JB often says “the weather in November the winter will remember”. -JB keeps hinting at cold in November but so far I see no sign of it

This is one of my favorite times of year, when the first pushes of cool/dry Canadian air plunge down following soon after most of 5 months with 65+ dewpoints mostly 70+). Makes walking enjoyable again and will likely give me lots of opportunities through mid April even if a mild winter.

That very high first half of Oct record high ACE estimate in 1893 is based partially on my own adjustment of the 63.5 total ACE generated by storm #9 (4th highest on record) by looking at the best track data available (yes, the 63.5 ACE is their educated guess based mainly on ships but also on land data from Bahamas/SE US) for the latest on record E MDR storm that made it to the CONUS. This caused major damage in SC: https://en.m.wikipedia.org/wiki/Accumulated_cyclone_energy urricane Nine 1893 Category 3 hurricane 63.5 20 days I also had to add ACE for another MH, storm #10 that hit SE LA as a 948 mb MH Oct 1-2.

12Z UKMET text still has TCG/STCG for the initially baroclinic low off the E coast. Not likely to bother any land regardless: NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 42 HOURS FORECAST POSITION AT T+ 42 : 35.0N 70.9W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 1200UTC 17.10.2024 48 36.1N 70.0W 1003 45 0000UTC 18.10.2024 60 38.1N 68.7W 994 48 1200UTC 18.10.2024 72 37.8N 66.4W 1000 46 0000UTC 19.10.2024 84 35.8N 63.3W 1008 38 1200UTC 19.10.2024 96 33.3N 61.9W 1013 31 0000UTC 20.10.2024 108 CEASED TRACKING

There’s still no ONI/RONI update for JAS. I’m assuming this is related to the Asheville data outage.

Been quite awhile. 2005-6, which followed El Niño, didn’t double and then was followed by El Niño. Prior to that, 1963-4, 64-5, 65-6 (Nino, Niña, Nino).

Very much fwiw: last 2 CANSIPS run show Modoki El Niño forming next summer.

The last two Euros at least have had no BN anomalies in Canada or in any of N America on the latest one for that matter for DJF as a whole. The runs are pretty strongly suggesting AN dominating at least the E half of Canada. I haven’t seen the month by month breakdown but the Euro has a much stronger warm signal than the CFS.

Also, the models have a surface low forming well offshore the E US. This year NHC hasn’t been naming these types. Not a big deal most likely but could it become T or ST? 12Z UK has it as one or other: (I think 0Z also had it) NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 60 HOURS FORECAST POSITION AT T+ 60 : 33.4N 72.4W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 0000UTC 17.10.2024 60 33.4N 72.4W 1011 33 1200UTC 17.10.2024 72 35.7N 69.9W 1006 42 0000UTC 18.10.2024 84 37.8N 66.5W 1001 43 1200UTC 18.10.2024 96 38.6N 63.3W 1001 46 0000UTC 19.10.2024 108 36.4N 59.5W 1008 38 1200UTC 19.10.2024 120 33.5N 56.5W 1014 32 0000UTC 20.10.2024 132 CEASED TRACKING

12Z Euro and CMC both approach Hispaniola moving WSW and then hook sharply right moving NNE to near Bermuda

12Z UKMET: further S than prior runs moving WSW through E Cuba into the NW Caribbean. This is similar to the 12Z Icon and JMA hit on E Cuba moving SW/WSW, a climatological rarity. Cuba is one of the more favored land areas for a landfall this time of year but not in that manner: TROPICAL DEPRESSION 94L ANALYSED POSITION : 17.0N 38.5W ATCF IDENTIFIER : AL942024 LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 1200UTC 14.10.2024 0 17.0N 38.5W 1014 23 0000UTC 15.10.2024 12 16.3N 40.5W 1013 23 1200UTC 15.10.2024 24 15.9N 42.1W 1012 24 0000UTC 16.10.2024 36 15.9N 44.6W 1011 24 1200UTC 16.10.2024 48 16.1N 47.8W 1012 26 0000UTC 17.10.2024 60 16.5N 51.1W 1011 27 1200UTC 17.10.2024 72 17.2N 55.1W 1012 28 0000UTC 18.10.2024 84 17.8N 58.6W 1011 26 1200UTC 18.10.2024 96 19.1N 61.6W 1011 27 0000UTC 19.10.2024 108 19.9N 64.7W 1010 28 1200UTC 19.10.2024 120 20.4N 67.9W 1009 30 0000UTC 20.10.2024 132 20.8N 71.1W 1007 31 1200UTC 20.10.2024 144 20.7N 74.0W 1006 31 0000UTC 21.10.2024 156 20.6N 75.9W 1005 31 1200UTC 21.10.2024 168 19.6N 78.1W 1005 28

Don, I just realized that this Euro winter outlook has 01/09/24 stamped on it. Did you realize that? Is this the latest? What about 01/10/24?

0Z UKMET: moving WSW underneath a deep high toward E Cuba: TROPICAL DEPRESSION 94L ANALYSED POSITION : 17.3N 36.3W ATCF IDENTIFIER : AL942024 LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 0000UTC 14.10.2024 0 17.3N 36.3W 1013 24 1200UTC 14.10.2024 12 17.2N 38.4W 1014 23 0000UTC 15.10.2024 24 16.7N 40.3W 1012 23 1200UTC 15.10.2024 36 16.4N 42.4W 1012 23 0000UTC 16.10.2024 48 16.6N 45.2W 1011 24 1200UTC 16.10.2024 60 16.8N 48.3W 1012 26 0000UTC 17.10.2024 72 17.7N 51.8W 1011 29 1200UTC 17.10.2024 84 18.6N 56.0W 1011 30 0000UTC 18.10.2024 96 19.9N 59.3W 1011 29 1200UTC 18.10.2024 108 21.4N 62.4W 1012 27 0000UTC 19.10.2024 120 22.3N 65.3W 1012 28 1200UTC 19.10.2024 132 22.5N 67.8W 1011 27 0000UTC 20.10.2024 144 22.2N 70.1W 1010 29 1200UTC 20.10.2024 156 21.4N 72.0W 1009 29 0000UTC 21.10.2024 168 20.8N 73.5W 1007 25

*Reposted to correct thread* The ACE calculations are in for the period 9/30-10/13 based on best track data: -2024 had a whopping 63.6, 3rd highest since 1851! This compares to 1991-2020 avg of only 12.3! Since 1851: -1893 had ~67 -2016 had ~65.5 -2024 had 63.6 -1878 was just below at ~59-60 Breaking it down into weeks back to 1951: 9/30-10/6: 1991-2020 avg 7.7 ~47.5 in 2016 32 in 2024 ~30 in 2015 So, 2024 had 2nd highest 9/30-10/6 ACE back to 1951 only behind 2016 and just ahead of 2015. 10/7-13: 1991-2020 avg 4.6 31.6 in 2024 24 in 2018 ~18 in 2016 ~11.5 in 2017 11 in 1995 10 in 2010, 2001 8 in 2020, 2014 So, 2024 by a large margin had the highest 10/7-13 ACE since 1851! Kudos to Euro Weeklies predicting weeks in advance significantly greater than avg ACE 9/30-10/13 (delay of peak by 4 weeks)!

*Reposted to correct thread:* The busiest week on today’s Euro Weeklies for ACE is unusually enough for this late, week 4: Nov 4-10. It projects as per the image below 2.7 times the 2004-23 mean ACE, which is 2. So, the prog is for 5-6 ACE for then. The prog for each of the two weeks prior is for ~5 each. So, 15-16 is progged for the 3 week period that’s often pretty quiet, 10/21-11/10. But with Nina and very warm Caribbean/Gulf, it would make sense. The most active areas per the run for 10/21-11/10 go from SW Gulf through W Car through far SE FL, and Bahamas/Bermuda. 11/4-10: 2.7 x mean 2004-23 ACE 11/4-10: most active areas are shaded

*Fwiw* JB keeps hinting at a cold Nov/Thanksgiving/Dec for the E US. I’m not putting much weight on that for obvious reasons. Also, on Oct 8th he ditched his +2 for Megapolis for Nov-Mar for a NN (+1). And that’s obviously subject to further cooling in later updates. Keep this in mind: Since at the very least 2014-5 (because they’re all circulating on the internet back to then), JB has yet to have a mild FINAL Megapolis winter forecast. With the number of mild winters (5 of the 10) there have been, that’s not a good record. The ones 3+ AN at NYC since 2014-5 for those who don’t know were 2015-6, 2016-7, 2019-20, 2022-3, and 2023-4. A. The 5 mild NYC winters (vs respective 30 yr mean): -JB had -1 for Nov-Mar 2023-4 vs actual of +4 (DJF N/A). So, he missed by -5 -He had +0.5 for DJF 2022-3 vs actual of +5. So, he missed by -4.5 -He had -2 for his final DJF 2019-20 (vs earlier fcast of +0.5) vs actual of +3.5. So, his final missed by -5.5. So, his earlier fcast was not as bad (miss by -3). -He had -2 for his final DJF 2016-7 (vs earlier fcast of 0) vs actual of +4. So, his final missed by -6. So, his earlier fcast wasn’t as bad (miss by -4). -He had -2 for both his initial and final fcasts for DJF 2015-6 vs actual of +5.5. So, he missed by -7.5. So, for the 5 mild NYC winters: -The avg of the absolute value of his final fcast misses was 5.5 and his avg bias was -5.5. The range was -4.5 to -7.5. -He revised 2 of the 5 significantly colder, which resulted in larger - misses. ————————— B. The 5 non-mild NYC winters: -2021-2 had -0.5 for final Nov-Mar (vs 0 for initial). The actual was +1 (DJF N/A). So, his final missed by -1.5 and his earlier fcast was slightly better (missed by -1.0). -2020-1 had +0.5 for his final DJF (vs +3 for his earlier). The actual was +0.5. So, his final was perfect! Also, his earlier fcast wasn’t so good (missed by +2.5) meaning his change was great! -2018-9 had -2 for his final/initial DJF vs actual of +0.5. So, he missed by -2.5. -2017-8 had 0 for his final DJF (vs +0.5 for initial). The actual was +0.5. So, his final missed by only -0.5. His earlier fcast was perfect. -2014-5 had -2.5 for his final DJF (vs -3 for initial). The actual was -4. So, his final missed by +1.5. This is the only one of the 10 that was actually cold, for which he missed too warm, and for which he revised warmer. This also was his coldest fcast. His earlier fcast was slightly better (miss by +1). So, for the 5 non-mild NYC winters: -The avg of the absolute value of his final fcast misses was 1. The avg bias was -0.5. The range: -2.5 to +1.5. -He revised 4 of the 5 (3 cooler and 1 warmer). ——————————— C. Summary of all of last 10 winters at NYC: -He did well when winter wasn’t mild as his bias for those was only -0.5 and avg absolute value of misses was only 1. His coldest fcast was for the coldest winter. -He did poorly when winter was mild with a bias/avg miss of -5.5 (avg absolute value of misses was 5.5). He didn’t predict a single mild winter. He was able to predict well the one cold winter. He’d be a much better forecaster if he’d improve on forecasting mild winters but that’s hard to do when he doesn’t forecast them. That’s why I route for him to predict mild and stick with it. -None of his 10 final forecasts were mild (warmest +0.5/NN) (5 were NN and 5 were BN) as they were from warmest to coldest: +0.5, +0.5, 0, -0.5, -1, -2, -2, -2, -2, -2.5 That means that IF his final fcast of +1 for 24-5 doesn’t change, it would still be the warmest since at least 2014-5 despite the cooler revision from +2 to +1. -6 of the 10 winters were +1 or warmer. The avg of the winters was +2 vs his avg of final fcasts of -1. So, he was too cold by 3 on avg for the 10 winters! So, a bias correction of +3 would probably be appropriate. -He predicted on avg -1.3 for the 5 warmest winters and -0.9 for the 5 coldest winters -He had revisions for 6 of the 10. Of these 6, 5 resulted in a worse forecast and only one a better forecast. Of these 6, 5 were revised cooler just like the one he just did for 2024-5. Only 2014-5 was revised slightly warmer. @bluewave @donsutherland1

Like clockwork and even earlier than I expected, predictable JB has just cooled his Nov-Mar forecast. Warning: this may just be a baby step on the way to more cooling…we’ll see. In 2020-21, he also had an initially mild E US that he drastically cooled in November. He has since at least 2014-5 not had a mild FINAL cold season forecast as 20-21’s was changed to NN (which in all fairness verified pretty well). Old one (8/22/24): New one (10/8/24): ~1F cooler from +2 to +1 in NE Megapolis, which isn’t trivial as +1 is NN to me meaning he’s ditched his somewhat mild NE fcast: @donsutherland1

1. Not officially because that (on ONI basis) is done retrospectively since several months of SST anomalies have to be -0.5C or colder in Nino 3.4 and it has just gotten there in recent weeks. 2. I actually prefer to look at it on a Relative ONI basis (RONI) because that much better takes into account recent warming of global tropical waters. Based on that, it entered La Niña territory nearly 3 months ago.

94L on 12Z UKMET: keeps it near steady state through entire run, which ends with it moving slowly (<10 mph) WNW well N of the Greater Antilles (I’d have to see H5 maps to determine if that would likely recurve safely from the US):MET OFFICE TROPICAL CYCLONE GUIDANCE FOR NORTH-EAST PACIFIC AND ATLANTICGLOBAL MODEL DATA TIME 1200UTC 13.10.2024TROPICAL DEPRESSION 94L ANALYSED POSITION : 17.9N 33.8WATCF IDENTIFIER : AL942024LEAD CENTRAL MAXIMUM WINDVERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)-------------- ---- -------- ------------- -------------1200UTC 13.10.2024 0 17.9N 33.8W 1013 250000UTC 14.10.2024 12 17.6N 36.6W 1013 241200UTC 14.10.2024 24 17.2N 38.6W 1013 230000UTC 15.10.2024 36 17.0N 40.3W 1012 231200UTC 15.10.2024 48 17.0N 42.4W 1011 250000UTC 16.10.2024 60 17.0N 45.2W 1011 261200UTC 16.10.2024 72 17.5N 48.3W 1011 290000UTC 17.10.2024 84 18.5N 51.8W 1011 321200UTC 17.10.2024 96 20.6N 55.5W 1011 330000UTC 18.10.2024 108 22.0N 58.1W 1011 301200UTC 18.10.2024 120 23.2N 60.3W 1013 290000UTC 19.10.2024 132 23.9N 62.3W 1013 251200UTC 19.10.2024 144 24.0N 64.5W 1012 300000UTC 20.10.2024 156 24.2N 66.0W 1011 311200UTC 20.10.2024 168 24.7N 67.5W 1009 29

Note that the Euro doesn’t even have the cold Canada like some others. Actually, the E half is downright mild (for Canada)!

Except that normals have warmed so much that modestly BN isn’t all that cold anymore. And then wait til we get to 2001-30 normals!

Only 6 of the last 45 winters averaged -NAO (sub -0.25): 1984-5, 1986-7, 1995-6, 2009-10, 2010-1, and 2020-1. All 6 had averaged sunspots under 35 and were within about 2 years of solar cycle minimums. Coincidence? Some feel there is a partial negative correlation of winter -NAO and winter sunspots. I’m leaning that way.

Despite things tending to calm down starting in late Oct, I fully expect more storms due to La Niña and the very warm Atlantic. I just hope that they’re not nearly as impactful especially in the CONUS as the westerlies come further south per climo. We’ll see. Impacts on the US generally go down late in Oct despite exceptions like Wilma and Sandy. GFS does tend to have a lot of phantoms in the long range in the W Caribbean/Gulf, regardless. So, we’ll have to see about those as I do expect more activity there.

Hopefully no more hits this season! Whereas nobody knows what will happen, climo is our ally now as usually things calm down overall a lot past mid Oct. So, fingers crossed, especially since average ACE has increased for late season.