Weak La Nina Winter

[AfewUniversesBelowNormal]

probably still strong early February

[raindancewx]

We're approaching our all time record streak for days without precipitation here, currently 80 days without precip, longest since 1956, record is 109. It's wetter (or unchanging) here than it used to be in every month but May/June over the last 100 years by 10-30%, so would expect some kind of big change in the pattern from that alone. The SOI may fall to a negative value in December from +10 to +11 in Oct/Nov, so that may be a good omen for precipitation. The blue and yellow areas are (highly) significant.

[raindancewx]

According to the BOM method of calculating the SOI, the huge monthly drop from November (+10.4) to a likely negative value in December (-3.1 for Dec 1-27, possibly lower by Dec 31), is quite rare for the 1931-2016 period. Best match is 1934, which went from +12.5 to -3.4. That's one of the Dust Bowl years...so not great for the USA. You have only four years with drops from +8 or more in November to negative values in December: 1934, 1976, 2001, 2013

The only years with a 12-20 point SOI drop from November to December are 1934, 1943, 1952, 1973, 1988, 2000, 2001 (mostly warm AMO, low solar years coincidentally). The blend of those years looks pretty similar to what I had for January for temperatures - warm in the East, fairly normal in the West, to slightly below normal by NV. We'll see.

[AfewUniversesBelowNormal]

western regions are almost neutral.. 

[AfewUniversesBelowNormal]

7 hours ago, raindancewx said:

According to the BOM method of calculating the SOI, the huge monthly drop from November (+10.4) to a likely negative value in December (-3.1 for Dec 1-27, possibly lower by Dec 31), is quite rare for the 1931-2016 period. Best match is 1934, which went from +12.5 to -3.4. That's one of the Dust Bowl years...so not great for the USA. You have only four years with drops from +8 or more in November to negative values in December: 1934, 1976, 2001, 2013

The only years with a 12-20 point SOI drop from November to December are 1934, 1943, 1952, 1973, 1988, 2000, 2001 (mostly warm AMO, low solar years coincidentally). The blend of those years looks pretty similar to what I had for January for temperatures - warm in the East, fairly normal in the West, to slightly below normal by NV. We'll see.

2013 a good pattern match.
Weird that the southern stream isn't more moisture. 

[raindancewx]

Nov SOI: +10.4

Dec SOI: -2.6

Big time drop historically for the period.

Also, the Canadian is out, it shows, as it did last month, the Nina shifting from East based in January to Central based in February, before rapidly collapsing in Spring. Most of the models have the event ending around April 1 - but we'll see. Canadian has a Nino developing in July, but its way too early to trust it on that.

[raindancewx]

NOAA says the Upper 300m of the oceans in the Nino regions warmed again in December in an anomaly sense.

YR    MON   130E-80W   160E-80W   180W-100W 

2017    1     0.18      0.07       0.01
2017    2     0.36      0.30       0.15
2017    3     0.43      0.38       0.22
2017    4     0.34      0.28       0.06
2017    5     0.37      0.36       0.30
2017    6     0.21      0.22       0.22
2017    7     0.13      0.15       0.16
2017    8    -0.19     -0.21      -0.40
2017    9    -0.45     -0.57      -0.79
2017   10    -0.54     -0.77      -0.97
2017   11    -0.41     -0.65      -0.84
2017   12    -0.31     -0.55      -0.75

Weeklies and monthlies should be out later today or this week. ONI probably by 1/8. Happy New Year everybody.

http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ocean/index/heat_content_index.txt

[raindancewx]

Some weakening at the surface.       
                Nino1+2      Nino3        Nino34        Nino4
 Week          SST SSTA     SST SSTA     SST SSTA     SST SSTA

 06SEP2017     20.4-0.1     24.3-0.6     26.2-0.6     28.7 0.1
 13SEP2017     19.7-0.7     24.0-0.9     26.1-0.6     28.7 0.0
 20SEP2017     19.3-1.1     23.9-1.0     26.3-0.4     28.7 0.0
 27SEP2017     19.5-1.0     24.4-0.5     26.5-0.2     28.4-0.2
 04OCT2017     19.3-1.4     24.7-0.2     26.7 0.0     28.7 0.1
 11OCT2017     19.5-1.3     24.4-0.5     26.2-0.5     28.5-0.1
 18OCT2017     19.5-1.4     23.9-1.1     25.9-0.8     28.3-0.4
 25OCT2017     19.6-1.4     24.2-0.8     26.2-0.5     28.5-0.2
 01NOV2017     20.4-0.8     24.4-0.6     26.3-0.4     28.7 0.1
 08NOV2017     20.2-1.2     23.8-1.2     25.6-1.1     28.3-0.3
 15NOV2017     20.6-1.0     23.8-1.1     25.6-1.1     28.2-0.4
 22NOV2017     20.6-1.2     23.9-1.1     25.9-0.8     28.5-0.1
 29NOV2017     20.8-1.3     23.9-1.1     25.9-0.7     28.5 0.0
 06DEC2017     20.8-1.6     24.1-1.0     25.7-0.8     28.2-0.3
 13DEC2017     21.3-1.3     24.0-1.1     25.8-0.8     28.1-0.3
 20DEC2017     21.6-1.4     23.8-1.4     25.6-1.0     28.1-0.3
 27DEC2017     22.1-1.3     24.4-0.9     26.0-0.6     28.2-0.2

[AfewUniversesBelowNormal]

Subsurface is really heating up. I get the feeling because of how last Spring warmed up so naturally that we will move into El Nino at least initially. 

[raindancewx]

I think the ONI for OND is going to be around -0.9C. Should be out by next Monday.

Historically, this is what happens after two clear La Nina winters in a row:

1949-50, 1950-51  ----> 1951-52 El Nino

1954-55, 1955-56  ----> 1956-57 La Nina / Cold Neutral

1970-71, 1971-72  ----> 1972-73 El Nino

1973-74, 1974-75  ----> 1975-76 La Nina

1974-75, 1975-76  ----> 1976-77 El Nino

1983-84, 1984-85  ----> 1985-86 La Nina / Cold Neutral

1998-99, 1999-00  ----> 2000-01 La Nina

1999-00, 2000-01  ----> 2001-02 Neutral

2007-08, 2008-09  ---->  2009-10 El Nino

2010-11, 2011-12  ----> 2012-13 Neutral

If you include borderline La Nina events, then you get a lot more cases:

1931-32, 1932-33  ---> 1933-34 La Nina

1932-33, 1933-34  ---> 1934-35 Neutral

1937-38, 1938-39  ---> 1939-40 El Nino

1948-49, 1949-50  ---> 1950-51 La Nina

1955-56, 1956-57  ---> 1957-58 El Nino

1966-67, 1967-68  ---> 1968-69 El Nino

1984-85, 1985-86  ---> 1986-87 El Nino

1995-96, 1996-97  ---> 1997-98 El Nino

For all 18 cases, you have nine El Nino events that follow after two La Nina winters / two ~La Nina-ish winters. Only six La Ninas.

I should say that "low-solar Neutral" is pretty rare historically for winter. Only ten cases in winters since 1930-31, and almost all are cold-Neutrals. Last year was sort of like that if you use only DJF and ignore July 2016 to Jan 2017. Also, since 1930-31, Nino 3.4 has never had a one-year increase greater than 2.6C in constant anomalies in the DJF to DJF period. So, if we end up around -0.8C this DJF, you can rule out another Super Nino at least, and there is a 95% chance the y/y increase would be under +1.8C if we head in that direction, so it would be a weak Nino in all likelihood. To me the three leading scenarios for next winter are: Weak La Nina (warmth is going to surface even if it reverses later), Cold Neutral (same logic, but with solar), Weak El Nino. Would go Weak Nina (40%), Weak Nino (40%), Cold Neutral (20%) for the moment.

I've done regressions on this for my area, and conceptually, my coldest winters are 1) low-solar El Ninos, that are 2) strong, and 3) after big La Ninas. So if we hit -0.8C or something for DJF, and then go into a weak El Nino next year, with low solar, would expect a pretty cold winter in the SW. El Ninos after El Ninos (like 1940-41, 1941-42, 1958-59, 1969-70, 1977-78, 1987-88, 2015-16) are never that cold here. If we go to Neutral in 2018-19, and then El Nino in 2019-20, that would kind of stink, wouldn't be that cold here. Another La Nina next year followed by an El Nino would be alright too I guess, if it actually rains or snows next year.

[raindancewx]

https://www.ncdc.noaa.gov/teleconnections/enso/indicators/sst.php

This isn't the data used for ONI, but it has Nino 1.2 down to -1.5C for December, and Nino 3.4 up a bit in December, to -0.79C in December from -0.86C in November.

[raindancewx]

If anyone wants to add years, I used the website "the wayback machine" to dig through the Pentad data to make this subsurface comparison. Subsurface is simultaneously much colder and much warmer in the tropical pacific than last year. Also very different from 2013. 

Kind of a blend of 2011 & 2012 subsurface? 2012 tried to become an El Nino briefly in Fall, before reverting back to cold Neutral.

Close to a strong La Nina in Nino 1.2 and Nino 3 in December says the European. Gradually becoming more east-central than east-based.

.

[AfewUniversesBelowNormal]

Will probably pop to +0.5 by MAM then different patterns. 

[raindancewx]

ONI came in at -0.9C for OND. Nov-Dec both right around -1C in Nino 3.4

Nino 1.2 came in at 21.44C for December, which is very very cold historically for that month,2007, 1974, 1975, 1967, 1955, 1954 are the only Decembers colder in that region since 1950. The 2010-11 La Nina was pretty strong, but it was 21.91C in December.

[AfewUniversesBelowNormal]

If DJF is -0.5 or below, this would be the first La Nina Winter in 6 years. Odds are probably less than 50% at this point. 

[Stebo]

35 minutes ago, AfewUniversesBelowNormal said:

If DJF is -0.5 or below, this would be the first La Nina Winter in 6 years. Odds are probably less than 50% at this point. 

I'll take the over on 50% 

[raindancewx]

If the event fails to meet -0.5C for DJF, it won't be classified as a La Nina by CPC, they consider 5 ONI trimesters as the threshold.

Honestly though, Dec & Jan will be cold enough that even if a big warm up comes later this month and in Feb, its still likely around -0.6C or so for DJF.

If we get a warm Nino 3.4 in Spring with Nino 1.2 still fairly cold - and I think that's fairly likely with a lot of the warm water nearing the surface no where near 1.2 yet - it'll be a pretty interesting pattern. Here are some years with say, +0.3C in MAM in Nino 3.4, but -0.3C in MAM in Nino 1.2 -

MAM	3.4	1.2
1952	0.14	-0.47
1982	0.49	-0.46
2003	0.10	-0.42
2004	0.31	-0.63
2005	0.57	-0.41
ONI	0.32	-0.48

That blend of years is actually quite wet in the South, so not sure I buy it. Would be my first wet March against 1981-2010 since 2007 if it verified.

[AfewUniversesBelowNormal]

Weird orientation for this point in the event. 

[raindancewx]

The SOI has been crashing hard again lately. January 1-7 is down to -1.63. The strongest correlations here between SOI leading precipitation totals are December for January to March and January for February to April, so would like to see it continue crash hard, to -7 or something, for January. Last SOI crash did eventually lead to some warming at the surface, will be interesting to see what the weeklies show tomorrow. 

Almost rained here last night, for the first time since October, dewpoint actually rose to 35F from -3F or so in 36 hours. Hopefully we get something with the 1/10 storm.

Some of the models are hinting that the big high blocking the West will get moved / destroyed in the coming days. Would be nice! Overall, this remains a remarkably dry winter so far nationally.

[AfewUniversesBelowNormal]

La Nina strongest its been. Weekly spike in the next week or two. Over on 50% on ONI La Nina, more like 85%.

[raindancewx]

If you standardize MAM ONI for Nino 1.2 & Nino 3.4 using a 1951-2010 base, you get pretty strong correlations between Dec temperatures and MAM in both regions for 1950-2016 v. 1951-2017. Raw SSTs in December in Nino 3.4 imply -0.27C for MAM ONI. Raw SSTs in December in Nino 1.2 imply -0.37C for MAM ONI. If that ends up being about right for both regions, its a pretty rare configuration for that period. Best blend for both regions in MAM would be Spring 1961, 1981, 1981, 1984, 2006. Should say, with the cold water below the surface by Nino 1.2, but warm water below the surface at the western part of Nino 3.4, the "colder east v. warmer west" look should continue, even if both areas do warm.

                Nino1+2      Nino3        Nino34        Nino4
 Week          SST SSTA     SST SSTA     SST SSTA     SST SSTA

 06DEC2017     20.8-1.6     24.1-1.0     25.7-0.8     28.2-0.3
 13DEC2017     21.3-1.3     24.0-1.1     25.8-0.8     28.1-0.3
 20DEC2017     21.6-1.4     23.8-1.4     25.6-1.0     28.1-0.3
 27DEC2017     22.1-1.3     24.4-0.9     26.0-0.6     28.2-0.2
 03JAN2018     22.9-0.8     24.0-1.4     25.8-0.8     28.3-0.1

 

[raindancewx]

Here is a visible sign of La Nina weakening:

It finally rained in Albuquerque (0.03" today!), first time since October 5th. Also, Flagstaff had 3 inches of snow last night, and 1.05" precipitation after seeing nothing for Dec 1-Jan 8.

[raindancewx]

Purple line is what I expect to happen. European seems to have warmed up what it expects for May-June from the last run?

[raindancewx]

JAMSTEC has the La Nina breaking up first in Nino 3, not where I would have guessed. It then has a weak El Nino trying to develop in Summer.

The Spring forecast is similar to before for the US, cold North, warm South, probably broadly correct, but it has trended the Western US, particularly TX and the NW, wetter.

[raindancewx]

This isn't an East-based Nina anymore - looks East-Central now, transitioning to Central based before it collapses?

 

[AfewUniversesBelowNormal]

850mb winds have made a big shift west too. I would think the movement west correlates to multi-year Nina's. It will also be really hard for this not to be torn apart in February-March with what's been pressing against it. 

[raindancewx]

This has been a remarkably dry winter so far for areas that are favored by La Nina historically. Look at the NW and OH Valley. The scale is for mm/day departures from average, so for 42 days, -0.33 to -0.66 represents -14mm to -28mm, which is -0.55 to -1.10 in inches. The near normal in Southern California is a bit abnormal too and largely from the last big storm around 1/9 or 1/10. Would expect California and the SW to gradually become less anomalously dry as the winter progresses further. Neat seeing S. TX as a big winner in a La Nina too.

 

 

[Hoosier]

37 minutes ago, raindancewx said:

This has been a remarkably dry winter so far for areas that are favored by La Nina historically. Look at the NW and OH Valley. The scale is for mm/day departures from average, so for 42 days, -0.33 to -0.66 represents -14mm to -28mm, which is -0.55 to -1.10 in inches. The near normal in Southern California is a bit abnormal too and largely from the last big storm around 1/9 or 1/10. Would expect California and the SW to gradually become less anomalously dry as the winter progresses further. Neat seeing S. TX as a big winner in a La Nina too.

 

 

Too much eastern toughing so far.  Have had very few systems rolling out of the southwest into the Ohio Valley/Lakes, but it appears we are in the process of shaking things up.

[raindancewx]

Still looking east-central now.

                Nino1+2      Nino3        Nino34        Nino4
 Week          SST SSTA     SST SSTA     SST SSTA     SST SSTA
 06DEC2017     20.8-1.6     24.1-1.0     25.7-0.8     28.2-0.3
 13DEC2017     21.3-1.3     24.0-1.1     25.8-0.8     28.1-0.3
 20DEC2017     21.6-1.4     23.8-1.4     25.6-1.0     28.1-0.3
 27DEC2017     22.1-1.3     24.4-0.9     26.0-0.6     28.2-0.2
 03JAN2018     22.9-0.8     24.0-1.4     25.8-0.8     28.3-0.1
 10JAN2018     23.3-0.9     24.3-1.3     25.6-0.9     28.2-0.1

 

[raindancewx]

We'll see if it lasts, but looks like some serious Nina-decay to me. The PDO & Nino 1.2 seem linked at a lag, so its interesting to see us reverting to a positive PDO look too with the Nino 1.2 cold falling apart.