GaWx

Indeed, taken at face value (yes I realize that’s a huge risk due to major unreliability and a tendency of recent years’ progs to be cold biased from what I can recall), this would mean a significantly colder NE than last winter. For example, it has NYC at only +2 vs +5 last winter, a large difference. For the SE, this map has a major +5+ torch, which would be much warmer than last year’s mainly NN to +3. Ouch but I’ve been expecting a warm winter here. That’s why I keep thinking about 2025-6 so much lol. It also has the SE mainly drier than normal. That’s common for especially the deep SE in a Niña. Totally expecting that but not worried about drought here right now. *Corrected for typo….cold not warm biased

0Z UKMET: TS landfall Wed (9/11) evening C LA; moves NE to far E TN, where it dissipates Fri night (9/13-4) NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 36 HOURS FORECAST POSITION AT T+ 36 : 20.5N 94.4W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 1200UTC 09.09.2024 36 20.5N 94.4W 1005 40 0000UTC 10.09.2024 48 21.8N 93.5W 1006 36 1200UTC 10.09.2024 60 23.1N 95.0W 1005 31 0000UTC 11.09.2024 72 24.7N 94.0W 1001 30 1200UTC 11.09.2024 84 26.9N 93.3W 998 38 0000UTC 12.09.2024 96 29.2N 91.6W 996 36 1200UTC 12.09.2024 108 31.8N 89.6W 999 32 0000UTC 13.09.2024 120 32.9N 88.8W 1002 20 1200UTC 13.09.2024 132 34.4N 87.9W 1006 16 0000UTC 14.09.2024 144 36.6N 84.0W 1008 14 1200UTC 14.09.2024 156 CEASED TRACKING ———————————- 0Z Euro: landfall W LA at 1001 mb TS on Thu 9/12; significantly weaker than 12Z but much stronger than yesterday’s 0Z, which had very little ——— TS landfall in LA at is my best guess as of now

This (Nov-Mar actually) is a nationwide torch? 1. Only torch is in S corridor like where I am (yippee lol although so I’ve been expecting it). 2. The NE is only ~+2, which is only modestly AN. Also, that would be ~3 colder than last winter. Midwest is NN, much colder than last winter. 3. He’s already doing his typical “monkey-wrenching” when he doesn’t go cold to keep his customers interested. For example, he’s already emphasizing cold Dec as well as things that can go “wrong” with his forecast. So, take the emphasis off the +2 and place it on a BN Dec. while also leaving the door wide open in clients’ minds of a colder revision. 4. His warmest initial forecast (+3 in NYC for example) of last 10 years was in 2020-1. But in Nov, that was revised significantly colder to NN. All of these years’ maps are on the internet via googling. That’s how I know.

Followup: CPC Aug NAO came in at +0.63, about where I expected it. So, despite that other version of Aug NAO being at a record high for that version (over +3), this one was only moderately positive. https://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/norm.nao.monthly.b5001.current.ascii.table

Other than the Gulf/Caribbean in the immediate future, I think that the most interesting AEW isn’t even in your list: one not coming off Africa til ~9/10. Looking at ensembles/ops, that’s the one leading to these operational (GFS/Euro/ICON/CMC) E MDR TCs. I don’t recall seeing one that active right off Africa on ensembles/operationals in at least quite awhile. And note that this is coming off Africa at about the same latitude as recent ones. Not further south. And yet it still may turn into something. Looking back at history for AEWs that developed in the E Atlantic near or just after Sept 10th, these were 3 of the worst. -Hugo (1989) -Gloria (1985) -Long Island Express (1938) I’m by no means saying a track anything like that would likely occur as many that develop early also recurve early. Rather I am saying that 9/10 still isn’t at all too late for a long-tracked CV storm, especially with cold neutral/weak Niña. Hope not but that’s a fact.

I suggest you put him/her on ignore if you don’t like the posts to keep from getting frustrated. It isn’t worth getting into a battle and disrupting the thread.

Here in the SE, 1957-8 was a top notch winter with very cold in Jan/Feb. along with a pretty rare 1” of snow way down here (in mid-Feb)! Savannah actually had a very rare 3 wintry precip events in JF, two of which were traces. ATL had a major winter storm in Feb. A near perfect El Niño for the Deep South! Maybe again in 2025-6??

I nominate @salbers to start the Invest 90L thread for two reasons: 1) I don’t want to. 2) salbers has been right on top of this and thus deserves the honor. If salbers doesn’t want to, I’d then nominate the ICON to start the thread.

That is ~-0.7 ONI low point, which compares to -0.3 last month and -0.1 two months back, but was similar to what the May and March runs were suggesting. It looks like it is correcting its typical warm bias and perhaps is also responding to the recent 3.4 drops and the new +SOI. The implied RONI based on my recent analysis of RONI minus ONI is that it would probably dip to ~-1.0 to -1.2 (moderate Nina) if the ONI were to actually dip to -0.7.

The idea is that high solar, which itself apparently contributes to atmospheric stability, may very well be a major contributing factor, not the sole factor. Was this stability forecasted? Anyone know? And can stability caused by high solar even be predicted by wx models?

Confirmation that NW GOM low is now Invest 90L: https://ftp.nhc.noaa.gov/atcf/btk/bal902024.dat

For the first time like the GFS/CMC, the Euro (12Z) has this NW Gulf low (1011 mb now). It then drifts S (similarly to ICON/UK/others) while getting stronger. It doesn’t reach peak strength til Saturday, when it gets down to 1003 mb at 27N. Keep in mind that the Euro like the GFS/CMC is playing catch-up. Rumor (i.e., unconfirmed) from an outside source is that this is now Invest 90L. ICON has been amazing with this although the 12Z Euro may have been the main deciding factor.

As you know I’ve been hoping to see actual research papers backing up the idea of a connection of very high sunspot numbers and the recent quiet in the Atlantic basin to supplement my own analysis of the actual numbers and your confidence. Fortunately, I just became aware of a good number of papers thanks to @jconsorwritten dating back to 2008 suggesting a partial negative correlation between sunspots and hurricane activity. The idea is (as we’ve already suspected) that when the sun has an increasing level of sunspots, the upper troposphere and lower stratosphere immediately get warmer (more of a rise than lower down) thus increasing atmospheric stability in a general sense. Of course proving this relationship isn’t easy due to other variables. But the authors discuss this and seem to have done well taking these other variables into account. (I was first made aware of a possible direct connection only last week by Joe D’Aleo and seconded by Bastardi.) The August SSN of 215 is the highest of the active era for any August. And August had only two NS (even though both were hurricanes). Furthermore, since Ernesto it has been exceedingly quiet relative to climo. In light of the following papers, this is probably a major contributor to the quiet: https://agupubs.onlinelibrary.wiley.com/doi/pdfdirect/10.1029/2008GL034431 https://myweb.fsu.edu/jelsner/PDF/Research/HodgesElsner2010.pdf http://myweb.fsu.edu/jelsner/temp/PDF/Research/ElsnerJaggerHodges2010.pdf https://onlinelibrary.wiley.com/doi/pdf/10.5402/2012/517962 https://sci-hub.ru/10.1016/j.jastp.2009.09.012 https://ephyslab.uvigo.es/publica/documents/file_358JASTP_2015.pdf @snowman19 Edit: though not as high as most of August, sunspots are still quite high with an avg of 184 so far this month. The dailies will be worthwhile to monitor throughout the month to see whether a significant drop occurs: 2024 09 01 2024.668 180 16.2 26 33 2024 09 02 2024.671 197 19.4 24 31 2024 09 03 2024.673 180 22.4 19 22 2024 09 04 2024.676 179 29.7 19 23 2024 09 05 2024.679 180 13.7 13 16

Fwiw, I added ENSO as per Webb’s table: 1874-75: 2nd coldest weak Nina 1875-76: 19th warmest neutral 1876-77: 19th coldest weak Nino 1877-78: 16th warmest Super Nino 1878-79: 14th coldest cold neutral 1879-80: 12th warmest weak Niña 1880-81: 13th coldest weak Nino 1881-82: 1st warmest. neutral

Regarding NW Gulf: Latest UKMET (12Z) now has TCG at hour 6, much sooner than the hour 60 of the 0Z run. It then drifts S through the weekend: NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 6 HOURS FORECAST POSITION AT T+ 6 : 27.9N 95.1W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 0000UTC 06.09.2024 12 28.1N 94.9W 1008 23 1200UTC 06.09.2024 24 28.3N 94.3W 1006 27 0000UTC 07.09.2024 36 27.7N 94.3W 1005 34 1200UTC 07.09.2024 48 25.3N 94.5W 1004 32 0000UTC 08.09.2024 60 24.2N 93.9W 1003 35 1200UTC 08.09.2024 72 CEASED TRACKING

The NW Gulf notwithstanding, there very well may be a connection between very high sunspot numbers and the recent quiet in the Atlantic basin. I just became aware of a good number of papers thanks to @jconsorwritten dating back to 2008 suggesting a partial negative correlation between sunspots and hurricane activity. The idea is that when the sun has an increasing level of sunspots, the upper troposphere and lower stratosphere immediately get warmer thus increasing atmospheric stability in a general sense. Of course proving this relationship isn’t easy due to other variables. But the authors discuss this and seem to have done well taking these other variables into account. I was first made aware of a possible connection only last week by Joe D’Aleo and seconded by Bastardi. But I didn’t feel comfortable depending on them saying this and thus wanted to see some actual studies. Well, now that I have seen the papers, I feel more confident that there really is something to this. The August SSN of 215 is the highest of the active era for any August. And August had only two NS (even though both were hurricanes). But since Ernesto it has been exceedingly quiet relative to climo. In light of the following papers, this may be a major contributor to the quiet. https://agupubs.onlinelibrary.wiley.com/doi/pdfdirect/10.1029/2008GL034431 https://myweb.fsu.edu/jelsner/PDF/Research/HodgesElsner2010.pdf http://myweb.fsu.edu/jelsner/temp/PDF/Research/ElsnerJaggerHodges2010.pdf https://onlinelibrary.wiley.com/doi/pdf/10.5402/2012/517962 https://sci-hub.ru/10.1016/j.jastp.2009.09.012 https://ephyslab.uvigo.es/publica/documents/file_358JASTP_2015.pdf

Kudos to @salbersbut also kudos to the ICON. No other model has even been close as far as consistently showing a closed surface low getting going around now in the NW Gulf. Folks can see it for themselves by looking at old runs going back many days right now at TT. That model has also been showing it move south toward the Bay of Campeche and getting stronger through the weekend. A few runs of the UKMET have had something but the ICON looks like the easy winner.

Thanks. I have no idea why the Arctic is shown as being cooler than the 1991-2020 normal on this weathermodels.com map.

Thank you. From your link per Joe D.: “The only year since 1998 since I have been doing this which has significantly departed for the seasons was 2001/02 winter when a strong second solar max in terms of solar flux and UV warmed low and mioddle latitude atmospheres and shrunk the polar vortex. I presented this at NWS regional winter workshops in the fall of 2002 and was invited the present that to CPC in Maryland. High ultraviolet produces warming through ozone chemistry, a finding that was speculated by Labitzke and van Loon (1997) and confirmed by Hansen's super modeler Drew Shindell (1999) who included ozone chemistry and flux/UV in a special climate model and got improved verficiation retrospectively..They all found a tendency for the warmth to work its way down from the high atmosphere where to the middle troposphere where it affected the jet stream and flow patterns. The peak in flux/UV in 2001/02 winter was very clear (from September 2001 to March 2002. The resultant warming in the low and middle latiudes was likewise very clear. This is the 500mb height in February. This looks more like the southern hemispehre with a tight polar vortec in blue - trapping real cold air in the polarregions and a warm ring in low and middle latitudes.” My concern is that he is showing only one period, the 2001-2 winter. For statistical credibility reasons, I’d like to see other years/analogs.

But Phil has yet to say that the high solar is even a possible factor in the upper atmospheric warming. I had hoped he would in yesterday’s update. Not even a mention of solar. To their credit the two Joes at WxBell have been. I’m open to that possibility, especially about the idea of a theoretical lowered ceiling on ACE during very high solar seasons based on my own analysis, but would also like to see peer reviewed studies to either back it up or else refute it. I don’t want to depend on WxBell just saying it. I’m open minded. I had never heard of this possible connection til last week thanks to Joe D.

It isn’t pointless because the NHC handles both tropical and subtropical. So, it is their responsibility. Don’t forget that ST storms get named, too.

The point I’m making in showing the progression of the last 6 is to see what the trend of the difference is going toward winter. The difference is important because the models only project ONI. I take those modeled ONIs and adjust them downward based on what I expect RONI-ONI to be. The last 6 have been -0.63, -0.62, -0.64, -0.61, -0.54, and -0.49. It looks like they’re finally starting to trend less negative. Based on that, I feel the difference could be near -0.40 by, say, SON.

This has been on the UKMET, Euro, and others for several days. I’ve been wondering whether or not it would be T, ST, or ET.

Let me restate as I wrote it wrong. I said JJA ONI-RONI was -0.49. I meant to say RONI-ONI was -0.49. RONI was -0.44 and ONI was +0.05. -0.44 - 0.05 = -0.49.

Would you please provide a link to this Arctic SST anomaly plot? I guess I’m not looking in the right place.