El Nino 2023-2024

[GaWx]

 How have E US temps been 1-3+ weeks following major SSWs (per ERA) in winter during El Niño? (Excluded 2/29/80 and 2/24/07 because too late to affect met winter)

1/31/58: very cold Feb

12/16/65: cold Jan mid-Atlantic south

11/28/68: cold Dec & 1st half Jan

1/2/70: very cold Jan, cold Feb

1/31/73: cold mid to late Feb

1/9/77: very cold mid Jan-early Feb

1/23/87: cool Feb

12/8/87: cold took 3 weeks to start (very late Dec) and continued through Jan

1/18/03: Feb very cold mid-ATL north/cool SE

2/9/10 (10 mb winds prior to this dropped to +2 m/s 1/29/10): very cold SE mid Feb-early Mar; cold Mid-Atl mid to late Feb

1/2/19: cold mid-Atl south mid to late Jan

 

  -So, ~half of Ninos since 1958 had a major SSW per ERA by mid Feb. vs 40% of others.

-So, for the 11 that had one, all (100%) had BN temps Mid-Atl south dominating for a 3-7 week period starting 1-3 weeks after the major SSW date. In the NE US, 8 of 11 (73%) had BN and others were NN.

 

Conclusion: Due to unanimous agreement of the 11 Nino cases: if a major SSW actually occurs in early Jan, I’ll be expecting a 3-7 week period of E US BN domination, with highest confidence mid-Atl south, starting mid or late Jan and ending anywhere from early Feb through early Mar. If instead one occurs in mid Jan, push these dates out 1-2 weeks. So, most likely period of cold due to major SSW in early to mid Jan would be late Jan-early Feb. It is possible that it will already be cold during or before any major SSW. I’m talking about aftereffects from the SSW, itself.

https://en.m.wikipedia.org/wiki/Sudden_stratospheric_warming

 

 

 

[40/70 Benchmark]

9 hours ago, stadiumwave said:

This may not look like much to some but the stratosphere forecast between Euro & GFS is a big difference:

 

Looks like the GFS suite is just more of a PV elongation, whereas the European decimates it.

[stadiumwave]

32 minutes ago, 40/70 Benchmark said:

Looks like the GFS suite is just more of a PV elongation, whereas the European decimates it.

 

12z EURO caved more to the GFS idea. 

[40/70 Benchmark]

1 hour ago, stadiumwave said:

 

12z EURO caved more to the GFS idea. 

I will be pretty suprised if we don't see a SSW, though it certainly looks as though it will not be in December. 

[Stormchaserchuck1]

Those maps are not a qualified 10mb warming event

[40/70 Benchmark]

6 minutes ago, Stormchaserchuck1 said:

Those maps are not a qualified 10mb warming event

Obviously....

[GaWx]

 The way things have been trending on recent Euro Weeklies, we may need a major SSW for multi-week cold potential. Hopefully for cold lovers they’ll reverse back colder. But yesterday’s Euro Weekly 2m temp map for 12/25-1/1 was the warmest run yet for that week for the E US (and yesterday’s 1/1-1/8 was also its warmest though not nearly this warm with the only E US BN suggested in the far SE US):

 

[GaWx]

 The prelude to any potential upcoming major SSW is starting to get in range on the non-extended GEFS. The Siberian warming on this 12z GEFS 384 is stronger than what’s been on earlier runs fwiw. These runs will be watched over the upcoming week to see whether or not an actual major SSW appears to be coming. For a major, it isn’t just the warming, itself. It is the reversal of mean 60N winds at 10 mb that defines it:

[GaWx]

  Today’s Euro Weeklies SPV is significantly weaker in late Dec and early Jan than for any recent run. There are far more members with a major SSW in early Jan and there are even 6% Dec 27-31 after there being only one on the prior 3 runs, combined. Just for 12/27-1/7, alone, I count ~30%! Then for 1/9-16, I count a whole lot more. This is the first run with a clear majority of members with one (60%+). (For the stat nerds like me, I see ~23 sub -10, 8 sub -15, 4 sub -20, 2 sub -25, and 1 sub -30.)

 

 

[GaWx]

 All of the sudden, today’s Euro Weekly for 1/8-15 came in much colder than yesterday and is the coldest for that week since it started being covered on Nov 30th:

 

 Also, today’s 12/25-1/1 isn’t quite as warm as yesterday’s.

[40/70 Benchmark]

11 minutes ago, GaWx said:

 All of the sudden, today’s Euro Weekly for 1/8-15 came in much colder than yesterday and is the coldest for that week since it started being covered on Nov 30th:

 

 Also, today’s 12/25-1/1 isn’t quite as warm as yesterday’s.

We are going to see volatility among medium and long range guidance during the transition time, so I advise everyone to be mindful of premature spiking of the football, regardless of expectation. 

[raindancewx]

MJO looks like it is going to rapidly weaken now. Not much support for a run through 8-1 at high amplitude. I think it dies in 7/8, maybe even 6.

The upcoming massive dump of moisture into Eastern NM in phase 6 reminds me of Goliath in 2015, when the MJO was in phase six as well. Someone in the High Plains of eastern NM or TX could luck into 1.5-3.0 inches of liquid equivalent, with most of it falling as snow. I enjoy snow, but I would prefer to not see the cattle ranchers lose tens of thousands of their livestock in this event. I'm a bit concerned someone is going to get a major freezing rain event out of this as well.  This system looks like it has much less cold than Goliath, so the snow/rain issue is going to be more of an issue than in 2015. Track will be key too, and the models never know what to do with cutoff lows over the high terrain.

I've always enjoyed the observations from Roswell in late Dec 2015 - temps range from +4 to +71, with 16 inches of snow reported.

2015-12-25	71	29	50.0	9.0	15	0	0.00	0.0	0
2015-12-26	51	25	38.0	-3.0	27	0	0.16	3.2	0
2015-12-27	30	24	27.0	-14.0	38	0	0.28	12.4	3
2015-12-28	32	10	21.0	-19.9	44	0	T	T	15
2015-12-29	31	4	17.5	-23.4	47	0	0.14	1.2	13
2015-12-30	28	8	18.0	-22.9	47	0	0.00	0.0	14
2015-12-31	37	10	23.5	-17.5	41	0	0.00	0.0	12

https://en.wikipedia.org/wiki/December_2015_North_American_storm_complex

[stadiumwave]

6 hours ago, GaWx said:

 All of the sudden, today’s Euro Weekly for 1/8-15 came in much colder than yesterday and is the coldest for that week since it started being covered on Nov 30th:

 

 Also, today’s 12/25-1/1 isn’t quite as warm as yesterday’s.

 

I mentioned a couple of days ago there are signs of the 2nd week of Jan...8-15...being colder per organic methods. I'm pretty certain of a trough, but anomalies are always in question. 

Fingers crossed for those colder anomaly solutions if today's update.

[stadiumwave]

I've been up in the air about whether a full blown SSW is needed. I've about decided....yes. Either full-blown reversal or a significant weakening event to shake things up. 

[Terpeast]

10 hours ago, stadiumwave said:

I've been up in the air about whether a full blown SSW is needed. I've about decided....yes. Either full-blown reversal or a significant weakening event to shake things up. 

Yeah it would be nice to shake things up for the back half of the winter. 

But as last night's storm proved, we don't really need a SSW. The mid-atlantic forum pulled a rabbit out of a hat with some getting up to 4" under the best banding (many got 1-2" which is more than what was forecasted). This happened in a lousy pattern... and it just snuck up on us inside 3 days.

And it's only Dec 11.

We will have our chances despite a less than ideal pattern, and even more chances when the pattern improves.

[stadiumwave]

CFS Weeklies really swinging to colder look 2nd week of JAN as we've been discussing:

 

That AO & NAO drop that far out is pretty significant. If models are correct on that period, and I think they're catching on, then expect that signal to intensify.

[stadiumwave]

1 minute ago, Terpeast said:

Yeah it would be nice to shake things up for the back half of the winter. 

But as last night's storm proved, we don't really need a SSW. The mid-atlantic forum pulled a rabbit out of a hat with some getting up to 4" under the best banding (many got 1-2" which is more than what was forecasted). This happened in a lousy pattern... and it just snuck up on us inside 3 days.

And it's only Dec 11.

We will have our chances despite a less than ideal pattern, and even more chances when the pattern improves.

 

Continued warming Strat warming episodes, weakening the SPV is probably fine as long as MJO cooperates. If not...need SSW & reset. 

[so_whats_happening]

Since the MJO forecasts have weakened considerably we also have weakened the potential WWB event as we head to mid to late month. There is still a little something there but nothing to tip the bucket more as of now. We can definitely see the area around 1+2 may fall even further coming up here. Last I saw was around 1.3 on OISST will have to check with the update later on.

[GaWx]

Today’s released weekly SST anomalies (which cover last week) show a dramatic cooling in 1+2 to only +1.3 from +2.1 the prior week! Nino 3 remained at +2.0 while Nino 3+4 dropped slightly from +2.0 to +1.9. Nino 4 dropped notably from +1.7 to +1.4. So, the bookends dropped while the middle two regions stayed about the same and have the warmest anomalies. This makes it currently a cross between EP and CP. With Nino 1+2 so much cooler now and Nino 4 still unusually warm for it, it is arguably a little more CP than EP.

 Regarding the current RONI, it is likely hanging only near low end strong (~+1.5 to +1.6). So, we currently based on RONI appear to have the equivalent of a low end strong CP/EP El Niño and nothing close to a super strength EP.

[so_whats_happening]

Latest TAO and CPC subsurface look. TAO im back to doing every 2 days.

Edit: I just noticed the bad data around the 1st to about the 4th on TAO. Looks like some buoys were down during that period giving it a funky look.

[snowman19]

16 minutes ago, GaWx said:

Today’s released weekly SST anomalies (which cover last week) show a dramatic cooling in 1+2 to only +1.3 from +2.1 the prior week! Nino 3 remained at +2.0 while Nino 3+4 dropped slightly from +2.0 to +1.9. Nino 4 dropped notably from +1.7 to +1.4. So, the bookends dropped while the middle two regions stayed about the same and have the warmest anomalies. This makes it currently a cross between EP and CP. With Nino 1+2 so much cooler now and Nino 4 still unusually warm for it, it is arguably a little more CP than EP.
 Regarding the current RONI, it is likely hanging only near low end strong (~+1.5 to +1.6). So, we currently based on RONI appear to have the equivalent of a low end strong CP/EP El Niño and nothing close to a super strength EP.

Was just about to post the CPC update, 3.4 and 3 have basically stagnated. OISST finally updated on Cyclonicwx, both CRW and OISST are at +2.0C in 3.4 as of yesterday. Got to wait and see what happens with the WWB once the MJO pushes into phase 7

 

[Typhoon Tip]

I little bit coarse but ...CPC's animation below appears to introduce an abrupt weakening at least in the surface temperature trends at the tale end of the animation -

 

[Terpeast]

11 minutes ago, Typhoon Tip said:

I little bit coarse but ...CPC's animation below appears to introduce an abrupt weakening at least in the surface temperature trends at the tale end of the animation -

 

Yeah I want to say that this has peaked, but last time I said that, it strengthened even more. So I’ll stay quiet lol

[mitchnick]

2 hours ago, so_whats_happening said:

Since the MJO forecasts have weakened considerably we also have weakened the potential WWB event as we head to mid to late month. There is still a little something there but nothing to tip the bucket more as of now. We can definitely see the area around 1+2 may fall even further coming up here. Last I saw was around 1.3 on OISST will have to check with the update later on.

Those are Gfs forecasts. Yesterday's Eps pretty much has it falling apart (almost.) I am posting the link instead of a pic because at the link you can look back at the prior 6 days of Eps forcasts. 

https://charts.ecmwf.int/products/mofc_multi_mjo_family_time_longitudes?base_time=202312100000&filter=no&parameter=zonal wind 850 hPa

[Typhoon Tip]

13 minutes ago, Terpeast said:

Yeah I want to say that this has peaked, but last time I said that, it strengthened even more. So I’ll stay quiet lol

Really ...  I was under the impression that some metrics just traded places more so. 

I think plateaued is fair enough - it may have giga moved above(below) but hasn't significantly enough to matter. 

Particularly not with RONI being real whether people want to admit it or understand it or not

[Typhoon Tip]

From my years of experience this appears to be the best/first evidence of a SSW burst and probably down-welling event for this 2023/late December:

https://www.cpc.ncep.noaa.gov/products/stratosphere/strat_a_f/

[GaWx]

On 11/28/2023 at 3:16 PM, 40/70 Benchmark said:

My guess is like .6 to .7 for next update and probably peaking at like 1.1 to 1.2

Bullseye! The MEI warmed from +0.3 in SO to +0.6 in NO. That warming is good news as the 10 coldest El Niño winters (in the SE US, TN, and at least nearby areas to the north) had a DJ MEI of +0.5 to +1.5. So, we needed the MEI to warm up and now we’ll need the next two MEIs to maintain this warmup and preferably warm a little more. The 10 coldest El Niño winters back to 1951-2 centered on the SE and nearby were 1957-8, 1963-4, 1965-6, 1968-9, 1969-70, 1976-7, 1977-8, 2002-3, 2009-10, and 2014-5. Per Webb’s table these were the rounded DJ MEIs:

+1.5, +0.9, +1.3, +1.2, +0.8, +0.8, +0.7, +1.0, +1.1, and +0.5.

 So, range of +0.5 to +1.5 for the DJ MEI with a mean of +0.95 and a median of +0.95. So, sweet spot near +1.0 for the 10 coldest in the SE and nearby. The NE’s list is probably not too dissimilar.

 

 El Niño SE winters with DJ MEI within +0.5 to +1.5 that weren’t cold:

-1958-9: +0.7 cool

-1979-80: +0.7 NN

-1986-7: +1.1 NN

-1987-8: +0.9 cool

-1991-2: +1.5 mild

-1994-5: +0.9 NN

-2006-7: +0.8 NN

 

  So, when DJ MEI was within +0.5 to +1.5 during El Niño, the SE had a cold winter 10 times, cool twice, NN 4 times, and mild once.

 When the DJ MEI was outside that range during El Niño (7 times with 4 higher and 3 lower) the SE had no cold winters. All of this likely largely applies to the NE, too. Actually, 1958-9 was downright cold there vs just cool in the SE.

—————-
MEI:

https://psl.noaa.gov/enso/mei/

[Terpeast]

3 minutes ago, GaWx said:

Bullseye! The MEI warmed from +0.3 in SO to +0.6 in NO. That warming is good news as the 10 coldest El Niño winters (at least in the SE US, TN, and at least nearby areas to the north) had a DJ MEI of +0.5 to +1.5. So, we needed the MEI to warm up. The 10 coldest El Niño winters back to 1951-2 were 1957-8, 1963-4, 1965-6, 1968-9, 1969-70, 1976-7, 1977-8, 2002-3, 2009-10, and 2014-5. Per Webb’s table these were the rounded DJ MEIs:

+1.5, +0.9, +1.3, +1.2, +0.8, +0.8, +0.7, +1.0, +1.1, and +0.5.

 So, range of +0.5 to +1.5 for the DJ MEI with a mean of +0.95 and a median of +0.95. So, sweet spot near +1.0 for the 10 coldest in the SE and nearby. The NE’s list is probably not too dissimilar.

—————-
MEI:

https://psl.noaa.gov/enso/mei/

Alright, great news! We're back in business! 

[stadiumwave]

UKMET updated...great looking JFM

500mb

 

2m Temps

 

850mb Temps

 

Precip

 

SST's

 

[stadiumwave]

1 hour ago, stadiumwave said:

UKMET updated...great looking JFM

500mb

 

2m Temps

 

850mb Temps

 

Precip

 

SST's

 

 

JMA updated...great JAN & FEB

JAN

 

FEB