GaWx

I didn’t mean that 1/22-29 is colder than 1/15-22 on the run as 1/15-22 is the coldest. I meant that 1/22-29 is the week that cooled off the most of any week vs what the prior run had. I’m not about to try to make a prediction of whether or not 1/15-22 will be the coldest of the entire winter. However, it will be during/near the coldest climo for many. So, should it end up as cold as what the EPS has, it would have a good shot at being the coldest week of the winter.

I go by the unrounded ONI peaking at +2.00+. Others may define it differently.

-The ONI for OND came in at +1.94, not quite super. -The RONI for OND came in at +1.51, barely strong. -Dec ERSST came in at +2.07 vs the Dec OISST of +1.99. So, ERSST continues to come in slightly warmer than OISST, which may be significant going forward as we see whether or not unrounded NDJ ONI comes in at +2.00+, which would give us a super. -Nov ERSST was +2.02. So, to get a super for NDJ, Jan ERSST only needs to be +1.91. With the slightly cooler OISST now up at +2.10, I consider that chance to be high as of now.

The Euro Weeklies for today are colder in the E US vs yesterday for all of the weeks covering 1/15-2/12. The week 1/22-29 is especially colder. Perhaps this is related to the weaker mean SPV at mid-month. It is somewhat surprising because the EPS MJO today is much stronger in phase 4 at midmonth.

What the? The EPS mean for 1/17-18 fell sharply from yesterday’s +14 to today’s +6. There are ~~20% of members with a major SSW 1/15-19 vs only 5% yesterday. We know that the EPS has been strongly biased to the too weak side in recent weeks. So, I’m going to assume this is just a burp, especially with the other 0Z ensembles not showing this:

The 0Z EPS (bc) forecasted mid Jan mean phase 4 MJO amplitude has increased significantly since yesterday, not what I wanted to see for midmonth: Yesterday’s (1/2) EPS had ~1.00 (right on circle and then going inside it) phase 4 amp for 1/17: Today’s (1/3) EPS has a well outside the circle ~1.65 phase 4 amp for 1/17 (hoping this is just a burp):

The period starting near the end of the 8-14 looks to be when the cold moves SE into the E US per the last several EPS runs. There are indications of an Arctic high plunging down into the N Plains ~1/16-7. And that interestingly enough looks to be when the MJO is in the MC phases. Note though that the EPS and CMC have only a weak/near or inside COD MC, which would allow for a better chance for cold then. OTOH, the GEFS is much warmer then in the E US, not surprising since it has a very strong MC MJO: Note also that the GLAAM is per this CFS rising to a + soon afterward:

Correct as early Feb is near normal.

Today’s Euro Weekly for Jan 15-22 is still the coldest week:

Latest WCS PDO up to -0.63, highest since late October:

The 1/1 Euro Weeklies have an even stronger SPV late Jan/early Feb with the ensemble mean right at climo then (see below). (Look in my quoted post to see how much weaker was the SPV on the 12/26 run.) The last two weeks of the run, 1/29-2/5 and 2/5-12, warmed notably in the E US vs yesterday’s run (connection to stronger SPV??). OTOH before that, the week of 1/15-22 on the 1/1 Weeklies got even colder in the E US with BN temps nearly everywhere (see below). This is now the coldest week of the run in the E US as a whole! Also, keep in mind that this is during about the coldest climo of the winter for many. Interestingly, the models are suggesting that the MJO will then be in the MC though hopefully weak. Last winter’s coldest E US was when it was in the MC. Though it appears there might then be a moderate -PNA, there looks to then be a strong -NAO/-AO largely running the show. The run for 1/15-22 from just 6 days earlier (12/26 run posted in my quoted post) had AN temps for most of the E US!

The final week of the 12/31/23 run, which is for 2/5-12.

1. Yesterday’s OISST 3.4 is making a good case for a super El Niño (+2.00+ ONI peak): 2. OTOH, the Dec OHC came in at only +1.11: https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ocean/index/heat_content_index.txt

The latest Euro Weeklies (12/31 run) has normal or BN temps in the SE US throughout the run, including a strong signal for cold in its final week fwiw (not easy to do that far out on a 101 member run).

I’m still amazed at how the EPS went from this on 12/26/23 run (mean down to -3 and highest rest of run only +16): To this just 5 days later (12/31 run) (mean down only to +10 and lowest Jan 9th through end up at +17): However, despite that, the 12/31 run overall is a significantly colder run for much of the US, including the E US, especially for this week: Week of 1/15-22: 12/26/23 run: 12/31/23 run: Also, look at how cold on the 12/31/23 run is the week of 2/5-12, the coldest by a good margin in the E US of the four runs extending that far:

This EPS map for Jan 12th, should it verify closely, would be more typical of La Niña than El Niño with the -PNA/Aleutian High/SE ridge. This is something that I recall seeing very little of so far this winter. I’m assuming that this would be quite transient due to the El Niño, especially once the MJO gets past phases 4-6. Also, note that the SER (which I obviously hate to see) would be pretty stout then despite the coexisting strong -NAO/moderate -AO. I certainly hope the SE ridge would be temporary. In the meantime, I’ll be enjoying the cold that is going to dominate over the next 6 or so days:

1. OTOH, a major SSW is the gold standard for determining the likelihood of a SPV warming later translating down into the troposphere and then very often, especially during El Niño resulting on its own in a cold E US starting a couple of weeks later. With one no longer being imminent in early Jan like appeared to be the case just 4 days ago, it certainly is disappointing to me (as one who doesn’t like to sugarcoat in an effort to come across as objective as possible) since I prefer a long-lasting cold dominated pattern. I’ll still be hunting for one later in the season though I hope it wouldn’t have to wait til mid Feb like last year since that would delay the most likely start of the strong effects til early March. Otherwise, there are other factors that affect our wx (like El Niño, itself, +PNA, -AO, -NAO, -EPO, weak MJO, etc) that often lead to a cold E US pattern on their own. In the meantime here it has been cold the last couple of days and is expected to be cold dominated next week, which I’m loving. That would mean through early Jan a near normal winter to that point for much of the SE US, which I’m content about because it has been hard to get in recent years. 2. Updated GLAAM: fwiw this latest CFS run has it shifting to a La Niña pattern favoring -GLAAM in mid Jan, which is consistent with MC MJO phases being projected for then:

The warming is still strong/impressive but the wind reversal hasn’t held. So, headed for a minor SSW it appears. It doesn’t matter how much warming there is. I don’t think models are preprogrammed to predict/biased toward a major SSW based on past cases like 2/16/23..

I agree. I assumed he was asking about a major SSW. The chance for that in early Jan has gone from very likely per EPS/GEPS to only slight on all 3 major ens.

No, they’re showing unlikely now.

I'd agree with your post if you changed one word, "no". I wouldn't at all say "no" value. That is simply not true. Your overall point of not relying on model output is understood but saying no value is hyperbole. Thus I still see plenty of value and thus will continue to follow and post model output.

I’m still amazed at how the Euro weeklies went from this trend, which covers through the 12/24 run: followed by the strongest signal for an early Jan major SSW (the 12/26 run), to the weakest signal for an early Jan major, the 12/28 run as noted in my post earlier this morning. Simply astounding!

Yesterday’s 0Z EPS mean (0Z 12/28/23 run, latest available as of now on these graphs) went even further from the expectation of a major SSW in early Jan with only 4 members (8%) having one vs 20% on the 0Z 12/27 run per Allan. This 8% is only two days after the most impressively weak SPV for any 0Z run in early Jan, the 0Z 12/26 run (see 2nd of two graphs just above this in quoted post), a most unexpected turn of events!

Based on the tweet from Allan saying only 20% major SSWs on today’s 0Z EPS, here’s what some of us have been waiting for to see if it agreed: it seems to be in agreement in being much less impressive in early Jan! The mean dips down only to +5 on Jan 6th vs yesterday’s -3: Compare that to the very impressive run from yesterday at 0Z, what then was about the most impressive yet with a dip of the mean to -3 on Jan 6th: So, that means that today’s 0Z EPS, GEFS, GEPS, FNMOC ens, and GFS are all less impressive than 24 hours ago. Will we now get a @mitchnickstyle reversal tomorrow? Stay tuned!

I think that the subsurface already peaked in Nov.