GaWx

1. I’ve never heard about this. Interesting. 2. Ronnie unfortunately didn’t post a link to the study from which the tweet’s figure 1 analysis of SSN vs TC count comes. Ronnie says that strength is affected, but figure 1 says nothing about strength. 3. The study cited by the tweet says no connection between annual TC count/SSN. But it does suggest -correlation between 11 yr moving avgs. It shows 1964-2021. From late 80s-2021 as 11 year moving avg of TC count has risen, the 11 year moving avg of SSN has been dropping. I’m wondering if this could really be correlation without causation. We know the 11 year moving avg of TC count has been rising the last few decades due to +AMO/rising SSTs. But also NHC seems to have been naming more weak systems. Did the weakening in the prior few sunspot cycles also contribute to those increased TC counts? If so, we should start to see a drop in 11 year moving avg TC count as we go through next few years due to last 2 yrs of very active sunspots causing a new rise in SSN 11 yr avg. If there really is a connection, what is the scientific reasoning? 4. Looking at individual years, highest TC counts vs nearby averages included 2020, 2005, 1995, 1969, 1954, 1950, 1949, 1936, 1933, 1916, and 1887. What was ASO SSN for those high TC count seasons? 2020: 8 2005: 37 1995: 22 1969: 135 1954: 8 1950: 93 1949: 189 1936: 140 1933: 5 1916: 73 1887: 20 AVG: 39 Longterm avg SSN is likely ~~75. Thus, the avg of 39 for high TC seasons is pretty low. So, out of these 11 seasons, 6 had well below avg SSNs in ASO. Only 3 of the 11 has well above avg SSNs. Thus, this data suggests there may be a modest correlation between high TC count years and low SSN years though nothing earth shattering, especially considering a fairly small sample size.

I forgot to mention this. Note that a good number of these extreme cold E US WB CFS maps have been showing near normal in/near N Lower Michigan/E Upper MI while many of the same ones also show the strongest cold anomalies just 200-250 miles to the S near Chicago. That’s obviously from a flaw.

Here we go again. Yesterday, JB posted an insanely cold WB CFS 2m map for Jan-Mar 2025 as if it were worthy enough to show. The crazy map is shown in this American Wx post below (thank you @FPizzfor letting the members know about this insanity): For those who haven't been following this, the WB versions of the CFS model have been way out in left field compared to both the Tropical Tidbits versions (yes the SAME model!) as well as other long ranged models. One thing the WB CFS maps have literally been showing are polar opposite SST anomalies to TT CFS for the same periods! JB is posting these likely due to a combo of his off the chart weenieness and for increased WB clients/clicks. He's sunk to a new low imho. This map is literally showing the coldest Jan-Mar 2025 in the E 2/3 of the US going back to the late 1800s and by a significant margin. He picks and chooses the coldest individual WB CFS 2m runs to post. And they're not even real! There obviously are serious flaws in the WB algos related to its CFS output. JB needs to be called out for this nonsense as often as he posts flawed/fake crapola like this. This is bottom of the barrel. Note that a good number of these extreme cold E US WB CFS maps have been showing near normal in/near N Lower Michigan/E Upper MI while many of the same ones also show the strongest cold anomalies just 200-250 miles to the S near Chicago. That’s obviously from a flaw. *Edit: I don’t think JB even realizes that WB CFS output is flawed. I’m confident he doesn’t compare it to TT CFS. @donsutherland1

LMAO! I assume you're posting this for the comedy aspect. For those who haven't been following this, the WB versions of the CFS model have been way out in left field compared to both the Tropical Tidbits versions (yes the SAME model!) as well as other long ranged models. One thing the WB CFS maps have literally been showing are polar opposite SST anomalies to TT CFS for the same periods! JB is posting these likely due to a combo of his off the chart weenieness and for increased WB clients/clicks. He's sunk to a new low imho. This map is literally showing the coldest Jan-Mar 2025 in the E 2/3 of the US going back to the late 1800s and by a significant margin. He picks and chooses the coldest individual WB CFS 2m runs to post. And they're not even real! There obviously are serious flaws in the WB algos related to its CFS output. JB needs to be called out for this nonsense as often as he posts flawed/fake crapola like this. This is bottom of the barrel. *Edit: I don’t think JB even realizes that WB CFS output is flawed. I’m confident he doesn’t compare it to TT CFS.

CSU updated 2024 forecast unchanged from April: https://tropical.colostate.edu/Forecast/2024-06.pdf

This is now the 1st Invest of the season, 90L.

0Z UKMET: 1. keeps streak going to 7 of runs with a TC off the SE US coast: NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 42 HOURS FORECAST POSITION AT T+ 42 : 30.3N 77.4W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 0000UTC 13.06.2024 48 30.6N 77.5W 1010 31 1200UTC 13.06.2024 60 32.4N 74.1W 1009 35 0000UTC 14.06.2024 72 33.3N 73.8W 1010 32 1200UTC 14.06.2024 84 34.9N 71.9W 1011 28 0000UTC 15.06.2024 96 38.6N 67.7W 1007 36 1200UTC 15.06.2024 108 42.4N 62.9W 1004 37 0000UTC 16.06.2024 120 CEASED TRACKING —————————————- 2. Again the UKMET doesn’t have a W GOM TCG.

Today’s 12Z run is the 6th UKMET run in a row with the TCG off the SE coast with this one stronger (TS) but back to moving NE safely off the E coast (0Z was moving N toward NC): NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 48 HOURS FORECAST POSITION AT T+ 48 : 28.6N 78.9W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 1200UTC 12.06.2024 48 28.6N 78.9W 1007 35 0000UTC 13.06.2024 60 29.0N 78.3W 1009 33 1200UTC 13.06.2024 72 30.8N 75.2W 1007 44 0000UTC 14.06.2024 84 31.7N 74.5W 1008 36 1200UTC 14.06.2024 96 31.6N 73.3W 1009 33 0000UTC 15.06.2024 108 33.6N 71.4W 1008 31 1200UTC 15.06.2024 120 CEASED TRACKING Meanwhile, the 12Z UKMET dropped the W Gulf TCG that it had on its prior 2 runs.

The latest daily WCS PDO update continues the rapid bounce back to -1.47 (implying NOAA PDO has probably bounced back up to ~~-2.5) after being ~-3 (NOAA ~~-4) just eight days earlier:

The UKMET and JMA did best last year. The updated JMA (June run) for autumn ONI is very similar to the May run with a very slightly warmer prog that is still borderline weak Nino/cold neutral for ONI near -0.5 (implying RONI near borderline weak/moderate La Niña)(no significant bc needed since did well last year and longterm bias fairly small):

Actually though, with a fairly predictable bias correction, it can still be useful for trend purposes. Like if the next run were to be, say, +0.5 or -0.5, that would tell me the true trend of the progged ONI/RONI is probably warmer or cooler.

June 8th BoM updated run: SON ONI +0.07. The prior run (2 weeks ago) had -0.10. So, it rose slightly. But keep in mind it was the worst last year with the 6/3/23 run having +2.7 for SON and the 6/17/23 run having +3.0 for SON. Actual SON ONI was only +1.8. So, these runs were +0.9 and +1.2 too warm, respectively. Thus, if we cool their +0.07 SON prog by 0.9 to 1.2, we get -0.8 to -1.1 for a bc ONI prog. And then this implied bc RONI prog would be -1.2 to -1.5 or cooler. Thus, the bc implied 6/8/24 BoM RONI prog for SON is for a moderate to strong La Niña.

The 0Z UKMET has a borderline TD/TS making landfall in W LA a week from now. This is the 2nd UKMET run in a row with this. The other run aimed for middle to upper TX but was still offshore at 168: NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 162 HOURS FORECAST POSITION AT T+162 : 28.6N 91.8W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 0000UTC 17.06.2024 168 29.5N 92.3W 1002 34

@mreaves @kdxken @Chrisrotary12 and others: if interested in AmericanWx US Open pool (no prizes…just for fun), go to the 2024 PGA Tour thread in the Sports Zone forum and pick SIX golfers along with your guess of the winning score to par of the US Open. To keep it more interesting and to add incentive/make it fairer to enter earlier, I will not allow any entrant with the identical six golfers that any earlier entrant already picked. To avoid confusion, I’m asking folks to enter only in that thread as opposed to here. Scoring rules will be identical to what was used for the PGA except you need to pick 6 instead of 5 golfers. Deadline is Thursday (6/13) at 6:30AM EDT. Thanks. There’s already one entrant (not me).

There have been another two days of steep rises with the latest WCS PDO all the way up to -1.70. It was ~-3.00 just one week ago! But it still looks like merely a big deadcat bounce after the prior plunge. The NOAA PDO is likely still down near -2.5 to -2.75.

1) UKMET runs since yesterday have been showing a very weak TC forming Wed or Thu off the SE US coast followed by NE movement OTS: Here’s today’s 12Z run for that one: NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 90 HOURS FORECAST POSITION AT T+ 90 : 29.4N 77.6W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 1200UTC 13.06.2024 96 29.8N 76.6W 1012 28 0000UTC 14.06.2024 108 30.8N 75.7W 1012 21 1200UTC 14.06.2024 120 32.2N 75.0W 1014 23 0000UTC 15.06.2024 132 CEASED TRACKING 2) This is the first UKMET run showing a TCG in the W GOM as it has just gotten to within the 168 hr range. This one has significantly lower SLP than the TC it has for off the SE US. It is then moving NW toward the middle to upper TX coast: NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 162 HOURS FORECAST POSITION AT T+162 : 26.1N 92.9W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 1200UTC 16.06.2024 168 27.2N 93.8W 1003 26

I was at 96.2 at 3:10PM. Some 3PM temps: KSAV 95, KCHS 95, KSSI 97, KJAX 97, KGNV 95, KTLH 97, KVLD 96, KAYS 95. Skies are clear with no haze and winds are from the W, the typical direction for the hottest highs in summer. These are all at or near the hottest of the YTD. One good thing is that DPs aren’t too bad with upper 50s to low 60s most areas. Edit: 97.5 for me at 3:43PM! Edit #2: I hit my high at 97.5 again at 4:20PM Highs: SAV, CHS, GNV: 96; SVN: 97; JAX, VLD: 98; TLH: 99; Mods, please pin this thread. Thanks. @buckeyefan1

Chesco, Have you analyzed # of lows by decade at or above a certain high level, such as # aoa 75?

If you’re referring to ONI, I’d largely agree as of now at least. I count -1.5- low point as strong. But in terms of RONI, the data I’ve analyzed suggests a -1.5- low point is still a good possibility, especially when considering the bc June Euro implied prog of -1.4 or lower for RONI per my analysis above.

# of highs of 100+/95+ in Savannah, GA: 1900s: 7/83 1910s: 7/108 1920s: 10/136 1930s: 18/178 1940s: 27/190 1950s: 24/221 1960s: 3/118 1970s: 10/112 1980s: 47/289 1990s: 26/228 2000s: 9/159 2010s: 26/293 AVG: 18/181 Largest#: 1980s/2010s Smallest #: 1960s/1900s (2020-3: 1/79)

Note that the far EPAC MDR has a decent sized area near 31C with no area anywhere near that big in the nearby WCAR/GOM. That is actually at record warmth there just like the WCar/BoC have record warmth. Do you think that this being the warmest area could keep energy from concentrating enough in the WCar/GOM to form a TC?

June OND Euro prog for ONI/actual ONI/RONI ’23 +2.04/+1.92/+1.49 ’22 -0.25/-0.92/-1.03 ’21 -0.30/-0.98/-1.21 ’20 -0.49/-1.27/-1.52 ’19 +0.67/+0.51/+0.24 ‘18 +1.1/+0.9/+0.8 ’17 +0.4/-0.8/-1.1 ‘16 -0.4/-0.7/-1.1 ’15 +2.4/+2.6/+2.3 ’14 +1.3/+0.6/+0.5 ’13 +0.6/-0.2/-0.2 ‘12 +1.2/+0.1/-0.1 *’11 +0.1/-1.0/-0.9 *’10 -1.0/-1.6/-1.7 *’09 +1.3/+1.0/+0.9 *’08 +0.3/-0.4/-0.4 *’07 -1.1/-1.3/-1.3 AVG +0.5/-0.1/-0.3 Analysis: - The June Euro avg miss for ONI was 0.6 too warm. - It missed too warm 16 of 17! - When there was no El Niño, it missed on avg too warm by 0.7. - When there was El Niño, it missed on avg only by +0.2. - Out of 17, biggest misses were +1.2 (‘17) and +1.1 (‘12 and ‘11) - June Euro is progging SON/OND at -0.3 (vs -0.5 in May). - Based on avg miss of +0.7 for non-Nino, bias corrected June Euro prog for OND ONI is -1.0. Based on largest miss of +1.2, OND ONI could end up as low as -1.5. Based on smallest miss for non-Nino of +0.2, OND ONI could end up as high as -0.5. - Based on the assumption that RONI, which in MAM was 0.64 cooler than ONI and has been at least 0.4 cooler than ONI for a year, will be at least 0.4 cooler than ONI in OND, this implies that bc June Euro OND RONI prog is for -1.4 or cooler. *SON instead of OND (OND N/A) Sources: Euro progs https://iri.columbia.edu/our-expertise/climate/forecasts/enso/current/?enso_tab=enso-sst_table Actual ONI: https://www.cpc.ncep.noaa.gov/data/indices/oni.ascii.txt Actual RONI: https://www.cpc.ncep.noaa.gov/data/indices/RONI.ascii.txt

Wow, what a two day rise of the WCS PDO! It rose ~0.6, the fastest two day increase on this chart. But this is likely just a dead-cat bounce reaction to the prior two week very steep drop. Even after this bounce, it is still very low (at -2.26) and the corresponding NOAA PDA is probably still down at ~-3 to -3.5.

I’m hopeful for the winter after this next one. I’m hoping El Niño will return in 2025-6. The Hunga Tonga volcano may favor a multi-year El Niño within 2025-9 per a paper I’ve linked the forum to. If so, maybe the PDO would finally go back to positive with the WPAC perhaps finally cooling down. If we get that combo, I could see 2025-6 being much colder than recent winters for much of the E US. 2025-6 would probably also have a falling -QBO, which during El Niño would favor a major SSW. Also fwiw, it would be the 2nd winter after the most recent major land based volcano eruption of earlier this year. Those winters tend to be somewhat cooler than the prior winter. Then as we approach the next solar min, I could see a -NAO driven winter either in 2028-9 or more likely in 2029-30. Coincidence or not, all six -NAO winters since 1979-80 have been with sunspots under 35 and within two years of a minimum. So, perhaps??

- There looks like an acceleration in the rise since 2011. - The largest annual rises (based on peak to peak) have been associated with the four strongest El Niño years but also in 2012 (following a two year La Niña) and 1999. 1999 is hard to explain. 1999’s rise over 1998 was so large that it nearly rose back to the 1997 peak, which is weird since it was in the midst of a similar strong La Niña to the 1998 Niña! - The biggest annual drops (based on peak to peak) were after the three strongest El Niño years. Thus, there’d be a nice drop for the 2024 peak vs 2023 peak assuming the pattern holds. Edit: - Looking at the animation, the annual peaks have been mostly in Oct (22) although I see 4 in Sep. and 4 in Nov. Why are the peaks almost always in autumn? - The one exception to the autumn peaks is 1998, which technically peaked on Jan 1st as it was slowly dropping from the big late Sep 1997 El Niño related peak. The 1998 autumn peak, which was in mid Sep, wasn’t able to quite reach the Jan 1st level. This can be clearly seen by slowing the animation way down. This slowdown can be done by pausing the animation and then manually controlling the animation via the bottom scroll bar. - So, summary of the annual peaks: -22 in Oct -4 in Sep -4 in Nov. -1 in Jan - There’s also a very minor secondary peak in most years within a month of March. Why? My hypothesis is that it is related to the typical 60N to 60S annual global ocean SST peak, which is in/near March as per the image at this link: https://climate.copernicus.eu/july-2023-global-air-and-ocean-temperatures-reach-new-record-highs - Based on peak to peak rises, 2015 looks like it was pretty close to 2023. Both peaks rose over 1 cm from their respective prior year peaks. - This article attributes El Niño related rises to more rainfall over the oceans. But I would have thought it would be due to spikes of warmth during El Niño leading to ocean expansion. Any opinions about this?