GaWx

The last 3 days’ SOIs have been sub -25. Despite them now bottoming out and about to rise back up, the July complete month might end up slightly negative. What’s been driving the recent strong -SOI days have been very high Darwin SLPs. For those who don’t follow the SOI closely, a developing La Niña favors +SOIs in late spring and especially summer+. AN Tahiti SLP and BN Darwin SLP correlates to +SOI. But recent Darwin SLPs have been anything but low. On the contrary, we just had 2 days of 1017.55+ with today in highly rarified territory at 1017.85. How rare is 1017.85? Since 1991 and prior to today, there had been only 4 days with Darwin SLP of 1017.85+: 1018.35: June 22, 2004 1017.90: July 25, 2023 1017.90: Aug 5, 2023 1017.85: Aug 12, 1994 Note that all of these other 4 1017.85+ Darwin days were during an incoming or already existent 1st year El Niño. That’s far from the case now. Since 1991 there’s been only one day during a year with a first year Niña immediately following a Nino that had a Darwin SLP >1017 mb: the 1017.15 mb of Aug 12, 1995. For Niña following Nino, highest daily Darwin SLP: 1995: 1017.15 1998: 1015.35 2005: 1016.00 2007: 1016.00 2010: 1014.65 2016: 1015.25

Chris, Are you able to change the climo periods from 1991-2020 for the bottom 5?

I agree and fully empathize with your view. It can get tiring reading wish-casting (no reasoning) over and over. The extreme example imo is Bastardi, who I can’t recall even one time forecasting a solidly warm NE US winter and sticking with it. That hurts forecasting credibility due to a perception of a lack of objectivity. OTOH, one can also go too far the other way, too, by becoming a “contra-weenie”. Contra-weenies will purposefully always forecast the opposite of what weenies want, whether well supported or not. Like is the case for weenies, forecasting credibility is reduced and is also tiring to read. In summary, having either bias be too dominant is often damaging to forecasting credibility. Although you usually provide excellent support for your posts and are a wonderful contributor/very knowledgeable (these threads wouldn’t be the same without you), I feel you did border on taking on the contra-weenie role at times for last winter’s forecasts. It almost seemed you had joy in emphasizing warm winter expectations just to stick it to the weenies. The best imo are balanced and are not pushed too much in either direction by emotion/desires. Just look at data as objectively as possible, whether or not the data is suggesting an outcome one wants.

The seemingly never-ending lagging of OISST Nino 3.4 continues: (even the RONI version of this would only be down to ~-0.3 to -0.4)

Nobody yet knows what part of the big 2023 step up was due to Hunga Tonga. Plus HT effects are projected to linger for years with only a slow reversal occurring.

Repost: Summary of latest SON ONI forecasts (subtract ~0.5 to estimate RONI): Euro: warmed 0.2 to ~-0.1 (has a longterm warm bias/slightly too warm last year but warm bias stronger when non-Nino) BoM: cooled 0.3 to ~-0.2 (huge warm bias last year) MeteoFrance: cooled 0.5 to ~-0.4 (strong warm bias) JMA: cooled 0.3 to ~-0.8 (no known significant bias/did well last year) UKMET: cooled 0.1 to ~-1.0 (did best last year/no known significant bias) CFS: warmed 0.1 to ~-1.1 (overall limited accuracy; I think it has cool bias) So, with the significantly cooler JMA/MeteoFrance, I’m thinking the chances for a solid weak La Niña per ONI are increasing again (vs cold neutral). This also means the chances for a moderate La Niña per RONI are increasing again (vs weak).

The above animation clearly shows that the top ~100m is solidly holding as a warm layer.

It looks like RDU’s highest today may end up “only” at 97 (high through 4:30PM) though it could sneak up to 98. Comparing to FAY and Winston, that’s not out of line as they have been similar today.

In that tweet Leon Simons said: “Tomorrow will be the 500th day in a row of North Atlantic Sea Surface Temperatures running above pre-2023 records. A year ago, many said this was just natural variability. They should come out and eat their shorts.” When considering the combination of El Niño and Hunga Tonga (both in the “natural” category), I think it might have been wise to not act so cocky and not act so high and mighty. Is he implying that he knows for sure that AGW/sulfate reduction alone, lead to this sudden jump? If so, how is it possible to be 100% sure? AGW has caused a much more gradual warming. Also, the reduction in sulfates has caused warming in recent years though nothing big suddenly happened just before 2023. Why would AGW/sulfate reduction suddenly cause this big jump and how could he be so sure that Hunga Tonga, which shot an enormous amount of greenhouse effect water vapor way up into the stratosphere, wasn’t a significant contributor in addition to El Niño? Also, it supposedly will take the rest of this decade before the bulk of that added water falls back to earth. The ongoing effects of Hunga Tonga are still being analyzed! I’m not saying HT has been a significant contributor and I’m not saying the opposite. It is unknown. His cockiness implying everything is already figured out is what bothers me here

RDU at 4PM is sunny but the temp is down to 96. So, I’m thinking the high will probably end up 100-101 and only outside shot that 102 may have been reached earlier. Edit: high Monday ended up at 101

What are you at now?

Sunny or not, I’m thinking it is too late in the day for RDU to rise all of the way to 105 when they’re “only” at 100 at 3PM. I’d say probably no more than 102-103. A 5 degree rise from 3PM seems like a lot even with full sun, especially with a dewpoint up at 73.

If your definition of hyperactive is # of NS, you may have a point although having 3 through July 22nd is actually above avg vs the mean. So, 2024 may very well not reach a near record # of storms like 2005/20. However, in terms of ACE so far, it is a far different story due to Beryl. In 2020, despite having 7 NS by ~7/22, the first hurricane wasn’t til after July 23. More later when I get time.

RDU 11AM today: 92/74 RDU 11AM yesterday: 91/72

Yeah, just 3-4 months after most recent sunspot max midpoint prog of Oct 2024/solar flux midpoint prog of Sep 2024. I think this experimental product is updated ~monthly: https://testbed.swpc.noaa.gov/products/solar-cycle-progression-updated-prediction-experimental The current cycle started Dec 2019.

The current cycle (25) had initially been expected to max out ~July of 2025 at a max of only 115. However it has been much more active than expected. Thus, the predicted max date has been revised to be earlier. The earlier max goes hand in hand with the higher amplitude, since stronger cycles typically rise faster and peak sooner than weaker cycles. As the figure below shows the sunspot max is now predicted to be within the period July 2024 through Jan 2025, whose midpoint of Oct 2024 is 9 months earlier than the July 2025 initial max prediction. The F10.7cm radio flux max is now predicted to occur within the interval Jul-Nov 2024:

If anyone here is interested, I’m doing one more AmericanWx pool this year, the British Open pool. If so go to the PGA Tour thread and make your picks there. This time I’m asking for 7 picks (instead of 6 picks) in addition to you picking the final score to par of the tourney winner. Make sure that your 7 picks aren’t identical to anyone who picks earlier. All scoring rules will be the same as what was used for the US Open. Deadline is 11:59PM EDT Wed 7/17.

The next 3-4 days look brutal with regard to the HI. With the heavy rainfall that RDU received last week, it will be interesting to see whether or not RDU resumes being hotter than FAY and other nearby areas. It is a near certainty the entire area will be hot but will RDU resume sticking out now that the drought has lessened? So far today, it looks pretty uniform with RDU and nearby mainly 92-3 at noon and FAY up at 95.

This model and all of the models were obviously much too cold last year in the E US and they have had a warm bias overall for a good number of years. But with the typical La Niña, W Canada to the N Plains/Lakes are often cold and New England is often near normal. So, this CFS map isn’t that far off from that. Of course this is very much a fwiw since the CFS has essentially no forecast value, especially that far out. However, I’d bet on the solid warmth it is showing down here. Also, I’m leaning toward a dry winter for much of the E US. I enjoy winter more than any other season no matter what. It is great for being outdoors.

Here’s a new paper with a hypothesis that the sudden strong warming surge that appeared last year was caused by the large amount of water vapor reaching well up into the strat. from Hunga Tonga: https://wattsupwiththat.com/2024/07/09/hunga-tonga-volcano-impact-on-record-warming/ He says that this amount of water vapor increase that high up into the strat by a volcanic eruption was likely a 1000+ year event due to just the right combo of a submarine eruption located near that amount below sea level (150m down) and of this magnitude (VEI of 5+). He said, “We know that strong volcanic eruptions, capable of reaching the stratosphere, can have a very strong effect on the climate for a few years, and that this effect can be delayed by more than a year.” A key to possibly buying into the author’s hypothesis is to accept his reasoning for why it took over a year for the NH to warm from it. From his figure 13: Note that it took til very late 2022/early 2023 for the sudden significant increase in water vapor between 25 and 40 km up at 45N lat. “Because the Tonga eruption is unprecedented, there is much about its effects that we do not understand. But we do know that the planetary greenhouse effect is very sensitive to changes in stratospheric water vapor because, unlike the troposphere, the stratosphere is very dry and far from greenhouse saturation.” “As a group of scientists showed in 2010, the effect of changes in stratospheric water vapor is so important that the warming between 2000 and 2009 was reduced by 25% because it decreased by 10%. And after the Tonga eruption, it increased by 10% because of the 150 million tons of water released into the stratosphere, so we could have experienced much of the warming of an entire decade in a single year.” Thoughts from anyone? I saw many comments from @bdgwxin the comments section. There is some really good discussion in there, including with the author.

I’ve done it but not recently.

In a very general sense (with wide variations depending on the specific atmospheric setup) a tropical cyclone (TC) in the MDR will tend to travel to the right of a tropical disturbance that doesn’t become a TC. So, slowing development near the CV Islands tends to mean a further left/lower latitude track. Lower latitude in the MDR means lowered chance of a safe recurve vs if had been positioned at a higher lat. as a result of becoming a TC further east. Same idea for weaker TC (lower latitude/lower chance for safe recurve) vs stronger TC (higher latitude/higher chance for safe recurve).

A pop up here lead to some close-by CTG lightning strikes, including one which seemed like it may have been right on my property and lead to the power blinking. Rainfall light so far/ongoing.

I’d love to get a 4” event as 3-4” tend to be ~once a generation event down here. I haven’t even had a T of wintry precip since Jan of 2018, which is the longest wintry precip drought on record. This area had 3-4” (or the liquid equiv (LE) in a mixed bag of wintry precip) in 12/1989, 2/1973, 2/1968, and 2/1934. The heaviest, which were from LE of 0.75”-1.25”+, included significant IP and/or ZR and occurred in 1/2018, 1/1922, and 2/1914. 1/1922 and 2/1914 had severe ZR. So, since 1900, this area has gotten the LE of 3-4”+ storms seven times or once every 18 years. The LE of 1”+ of snow has occurred ~16-20 times since 1900 or once every ~7 years. So, even just 1” is a pretty big deal down here.

I haven't seen him mention 2014-5 in recent weeks. But prior to that when he was showing random Weather Bell versions of CFS for next winter, he was referring to 2014-5 among other winters because a good number of the Weather Bell CFS runs were literally showing a 2014-5 like solid +PDO due to a combo of a 1000 mile wide 4000 mile long solid area of BN SST anomalies from E of Japan to just N of Hawaii along with the warmest anomalies in practically the entire Pacific just off of Western North America. But the odd thing is that the Trop Tidbits versions, which I trust way more, never showed anything of the sort as they showed a continued strong -PDO. There appear to be problems with the WxBell algos related to their CFS maps. I don't think JB even realizes it as I doubt he looks at TT maps. I have posted about this several times.