GaWx

Today’s Euro Weeklies are just about as active as yesterdays in early Jan with ~18 majors 1/1-9 vs ~19 yesterday. The total run has ~40 vs ~45 yesterday. I counted 9 extremes throughout vs a few more yesterday: Jan 1-8 10 mb temps/hts still looks similar:

Since it covers 150W to 160E, how much of the stronger and further west VP anomalies do you think have been caused by Nino 4 being at such strong levels for it relative to its climo? Per your map, the strongest VPs so far this month have been from 170W to 160E or right over Nino 4.

Regarding the bolded, whereas the current El Niño’s ONI is “very strong to super”, it isn’t when looking at both RONI and MEI as RONI is lower half of strong and MEI is low end moderate at best. But Nino 4 relative to its own climo had been very strong although it has cooled a good bit from its peak.

Regardless of whether or not we get an official major SSW, the Euro Weeklies have been quite consistent the last 3 weeks or so for the first week of Jan with a way warmer than normal Arctic and significantly displaced SPV at 10 mb. That’s impressively consistent and persistent implying quite a strong signal with no can kicking whatsoever! Run from 12/3/23 for 1/1-8/23: Today’s (12/18/23) run for 1/1-8/23:

12/18 Euro Weeklies: again not underneath the red line but still almost as active with ~20% majors 12/31-1/9 (vs 24% yesterday) with 19% of them 1/4-9. I count 9% extreme (sub -15) through the full run vs 15% yesterday. Full run rough estimate: 45% vs ~55% yesterday.

New Euro Weeklies remain BN to NN temps SE US through 1/29 with FL/deep SE BN just about every week. Precip: wettest anomalies deep SE/FL with AN to NN most everywhere else and no dry areas. So, typical El Niño climo ftw.

I’m no expert either. I just know that +GLAAM partially correlates to El Niño/+PNA and -GLAAM partially correlates to La Niña/-PNA/SE ridge. So, as someone in the SE US who prefers the best shot at BN temps and who thus doesn’t like a -PNA/SE ridge, I prefer +GLAAM to -GLAAM in general. El Niño climo ftw. But maybe a moderate +GLAAM vs very strong is generally best for all I know. What you said makes sense. A bit less El Niño influence? But the GLAAM drop appears temporary. And this is just the unreliable CFS. So, who knows if the dip will even occur? Who knows if the dip occurs but isn’t so temporary? CFS ensemble not trustworthy, especially over 2 weeks out!

Latest CFS GLAAM forecast: Compare that to this one from four days earlier: one can see that early Jan has fallen from 1+ to slightly negative

Today’s WCS OISST update has 3.4 at +2.03, down from +2.08 yesterday. In order to get an unrounded ONI of +2.00+, I had earlier been figuring that the daily would probably need to peak close to +2.40. However, recently ERSST has actually been as much as 0.10 warmer than OISST. So, that when combined with there having been such a long period hovering near +2.00 tells me that the daily OISST peak may not need to be higher than ~+2.20. If the Dec ERSST were to again come in warmer than OISST, it could very well end up in the +2.05 to +2.10 range. Combined with the +2.02 of Nov, that would put ND at +2.03 to +2.06. That would mean Jan could be as low as +1.90 and NDJ still end up +2.00+.

It now looks like ~Jan 3-6 is becoming the most likely period for any potential major SSW. That would still be 16-19 days out and would be right in the heart of the most favorable QBO east climo portion of winter for one. Thus I’d give it til by this weekend for the models to get more on top of this should it be real. Thus, the trend of the rest of this week’s runs will be quite telling whether it be yes or no. If real, I’d expect to see more op GFS runs from time to time similar to the 18Z from yesterday that was posted as they lead the way in Feb. This 6Z 12/18 GEFS 384 looks pretty interesting and more favorable than the comparable map from the 0Z GEFS 12/17 extended released last night:

Thanks for posting this. In advance of the 2/16/23 major SSW, the GFS op on a number of runs lead the way ahead of ensemble means in suggesting that one was quite possibly on the way. As far back as 1/31/23, when hardly any of 60 ensemble members showed one, the GFS had this (see orange line): note that there were only 2 (3%) ensemble members weaker: On 2/2/23, only 3 (5%) ens members were weaker: Similarly, only 3 (5%) members were weaker than the 2/3/23 GFS and only 5 (8%) members were weaker than the 2/5/23 GFS. By the way, the 0Z 12/17 GEFS extended had a mere 2 (6%) with a major SSW, by far the lowest in many runs! However, the 0Z 12/18 GEFS at 384 suggests that it will likely have more major SSWs than 12/17 when the extended comes out tomorrow evening.

If any of the McClellanville reports are official, they’d almost have to be alltime SC Dec records by a big margin. That’s insane! The Savannah area ended up with 3.5-5”, easily the biggest 24 hour rain in a very long time! And it lasted a full 24. I wonder when we last got that much in Dec. This storm will not be soon forgotten!

Though no longer below the red line, don’t fret because today’s update holds onto yesterday’s re-weakening of the SPV. I see ~24% majors 12/31-1/9. That is still 14-23 days out. Keep in mind as per my prior post that 15 days before the 2/16/23 wind reversal only 13% of ens members had a major. They started catching on much better 13 days before it. Thirteen days before 12/31-1/9 isn’t til 12/18-27. So, there’s still plenty of time for the ensembles to more emphatically show it, especially if it were to occur later in the 12/31-1/9 period and especially considering that that entire period is the most prime QBO east major SSW climo. The start of the active period has now gotten to just two weeks out. But I would now like to see the majors start to move to less than two weeks out over the next few days. The ens mean still gets down to +12 Jan 1-2, which is a mere 1/3 of climo and which is out 15-16 days. This is near where the mean of the ensembles was 15-16 days before the 2/16/23 major. I now count ~55 majors throughout the run vs ~50 yesterday and ~33 two days ago. I count 15 extreme (sub -15) vs 13% yesterday and 7-8% the prior two days:

Model consensus 12/25 fwiw threat of rain much of SE and mainly warmer than normal with SW upper flow. I say fwiw because it still being 8 days out means lots of uncertainty/model inaccuracy.

Down to 996 mb inland over N FL (Cross City). Gainesville 998 mb with ~5” of rainfall with still heavy showers in the area! That 998 mb ~ties their record low for Dec. It rained here all night. Edit: power out here since 9:45AM due to persistent gusty winds of ~40 mph. Power returned just over an hour later. Winds now picking up perhaps a little higher on backside of low with cold air advection. Will have to watch for potential additional outage. KSAV 11AM SLP 29.49”/999 mb, possibly near to bottoming out Record low Dec SLP ~29.35”/994 mb Edit: KSAV 2PM SLP 29.41”/996 mb

I agree. Looking back at the 2/16/23 major SSW (when zonal wind went <0), let’s see how long it took for the bulk of the ensemble members to get clued in. The runs from 2/1/23, 15 days out, still had little clue as a mere 8 of some 60 or so total ens members (only 13%) had a major SSW (though the GFS was strongly hinting at it similar to how a couple of recent GFS runs have already done): Not til the 2/3/23 runs (13 days out) did the ensembles really seem to be much more onto it: So, looking ahead to the potential one for early Jan, we’re talking perhaps near Jan 1-3. Jan 1st is still 15 days out while Jan 3rd is 17 days out. If anything, the ensembles are and have been showing a somewhat higher % of members in very early Jan with a major SSW this time than were being shown 15 days prior to the 2/16/23 event. This tells me that we’re still likely ~3-5 days from put up or shut up time. So, I’m thinking we probably have til ~Wed-Fri of this week to finally consistently start seeing a forecasted notable 60N 10 mb wind collapse from, say, near half the members if there really is going to be one in the first few days of 2024. Along with that, perhaps we’d see some GFS runs with majors. If any actual event were to instead not be coming til, say, 1/5-7, we’d then probably have still another week or so (say ~12/25) til put up or shut up time on the models.

My area has been getting pretty heavy rain the last 1/2 hour or so. Meanwhile, @pcbjr’s abode in FL (Gainesville/Hogtown) has been hit with heavy rain for several hours. Hopefully, flooding isn’t bad there.

Although the 0Z 12/16 extended GEFS isn’t quite as active as yesterday’s run overall (7 members/23% vs 8 members/26%), it actually is more active earlier as it has a respectable 5 members (16%) with a major SSW just within the 5 days 12/30-1/3. Yesterday’s had only 3 during 12/30-1/3. The day before had only two for then I believe. Even the big 12/11 run had no more than about the same for then. So, look out for the possibility of one within a few days of New Year’s, which as has been mentioned is a climo favored period for QBO east.

New Euro Weeklies NN to BN temperatures SE every week through 1/29 with FL BN every week! Precip AN favored every week nearer to coast with NN far inland and no dry areas@pcbjr

What he said to a good extent (though not 100% back as weak near New Yr): ~17% major 12/30-1/6 and back up to ~50% full run vs ~33% yest. Sig weaker mid to late Jan. Extreme ~13% vs 7-8% last 2 days and ~17% 3 runs ago. Also, back below red line most of 12/28-1/5!

Further to the above 0Z GFS image, the 10 mb at 60N winds (orange) gets down to <8 m/s at end with more drop likely past this. Despite EPS/GEFS runs consistently showing a notable % of members with a major SSW in early Jan, the level of weakness on this GFS is still somewhat of an outlier considering that run’s GEFS mean is at 20 m/s. However, should there really be a major SSW coming near then or soon after, model consensus would be showing this type of thing more often as it gets closer. We’ll know more and more as the coming days of runs are seen:

1. This 0Z 12/16 GFS 384 appears to be approaching a major SSW 12/31-1/1 with the SPV down to 65N and a huge high centered over N Canada/AK: 2. The 0Z 12/15 GEFS has a similar % of major SSW members to 12/14 for the full run. However, the mean is a bit weaker 1/2-11 due to a sig increase in them 1/2-6 with a whopping 7 majors (23%) just during that period vs only 2 (6%) in the 12/14 run for then. The 23% for 1/2-6 is actually the same as was the case for 1/2-6 on the 12/11 run that had 48% for its full run. The total is 8 (26%) 12/15 vs 7 (23%) 12/14.

Other than week 2 having 2-3 F AN temps in NW portions, the Euro Weeklies have NN to BN temps in the SE through Jan 29th. And this is with most members having no major SSW. Imagine what could happen in mid and especially late Jan if there is one.

They could since we’re still far enough out in time for that to occur. But by a week from today, the models will know a lot more based on the past. So, say by the 12/21-2 runs, if the runs don’t jump back quite a bit in the weaker direction, I’d then significantly reduce the chances in my mind for an early Jan major SSW. I like to give updates, especially those showing significant changes, whether or not it is what I want to see. I don’t want to come across as one who posts either mainly about what I want to happen nor the opposite. I want to come across as one trying to be as objective as possible for credibility reasons.

I assume you meant to say they shouldn’t. I see no problem with every day for both as they help for following trends. I like to see daily updates. Now if they ran, say, 4 times a day, I’d agree with you.