Weak La Nina Winter

[Paragon]

1 minute ago, 40/70 Benchmark said:

This isn't unique to the NAO, either....however obviously you want multi tele connector convergence for a stronger signal.

PNA is very important once south of NYC.

Yep, we were discussing this one regarding how the winter might unfold and the typical la nina bookend pattern.  Looking to find some way to avoid multiple weeks of thaw in January lol.  But if we get a toned down version of 1995-96 it's still pretty good as long as the wintry pattern comes back in February.

[raindancewx]

On 11/13/2017 at 9:57 PM, raindancewx said:

In this area of the world, the "warm over cold" feature, i.e. warm waters off Mexico/Central America north of cold waters in Nino 3 / Nino 1.2 often predates a dip in the storm track as major thunderstorms kick up on the boundary of the anomalies. Will be interesting to see if that happens in December. It seems like February is the protected month in the NE, January is the protected month in the SE/Midwest, and here in the West its December. "Protected" meaning no warming in high temperatures long-term over most areas. March in the West and December in the East seem to have the opposite tendency, with very fast warming.

I wasn't completely sure when I did my winter outlook if this feature would show up (it wasn't there even two weeks ago), but I thought it might - some of my winter analogs had it. December tends to be cold in the West when that feature shows up.

Look at 1943, 1996, 2008, 2012 - the boxes are warm over cold.

For anyone who saw this post in November, the warm north of cold feature appeared in 2008...and it snowed in Houston & New Orleans in 2008 too. It did snow in Southern NM, TX, and Mexico, but there was no moisture in the northern two thirds of NM unfortunately. Oh well, nice to see a major event from the 2008 analog repeat though. Looking back at the Tropical Tidbits map v. now, the La Nina does look less East-based to some degree.

[AfewUniversesBelowNormal]

It kind of sucks the direction of this thread. 

[raindancewx]

European continues to insist this event is done in March, maybe April. Has shown that two forecasts in a row now. Nino 3.4 (line is -0.5C).

Don't think I buy the near El Nino conditions by June shown on the latest update, but the subsurface is warming below the western part of Nino 3.4, so who knows? European seems to have the event peaking this month.

The Nino 1.2 forecast is for weakening, but the plume keeps Nino 1.2 in La Nina-ish conditions into May or June. The forecast for weakening in Nino 3.4, Nino 1.2 seems to be at about the same rate, but Nino 1.2 is colder, so would remain cold there longer.

[raindancewx]

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

 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

[AfewUniversesBelowNormal]

La Nina has made a huge comeback and is a localized burst of -2.5 now, still strengthening. 

It's totally in a strong feedback loop right now with the North Pacific. 

[nzucker]

12 hours ago, StormchaserChuck said:

La Nina has made a huge comeback and is a localized burst of -2.5 now, still strengthening. 

It's totally in a strong feedback loop right now with the North Pacific. 

Weren't you just forecaating its demise? Does this affect your view of its evolution?

[AfewUniversesBelowNormal]

It's a zonal wind burst that will likely last 2 weeks. 

[raindancewx]

Nate Mantua sent out the latest PDO value - came in +0.15 for November. Up from +0.05 in October, but down from +1.88 last November.

http://research.jisao.washington.edu/pdo/PDO.latest

[raindancewx]

The latest MEI update says the La Nina, despite the cold Nino 1.2, is mostly misbehaving in that zone: https://www.esrl.noaa.gov/psd/enso/mei/

With the MEI showing weakening La Niña-like conditions, five out of six key anomalies in the MEI component fields flag La Niña. Key anomalies refer to values in excess of one standard deviation, or one sigma in support of either ENSO phase (compare to loadings figure).

Starting with the La Niña features, significant positive anomalies (coinciding with high negative loadings) flag anomalously warm sea surface (S) and air temperatures (A) east of Australia, as well as increased cloudiness (C) over the Maritime Continent. Significant negative anomalies (coinciding with high positive loadings) indicate anomalously low sea level pressure (P) over the western equatorial Pacific as well as enhanced easterlies (U) along the Equator near the dateline. The lone opposing indicator is found in anomalously low SLP (P) over the eastern equatorial Pacific, consistent with El Niño. It is noteworthy that all five La Niña indicators are currently found over the western Pacific, while the eastern Pacific is not participating (or even showing opposite anomalies).

[AfewUniversesBelowNormal]

subsurface cold-warm pool has retrograded some. Longer La Nina, maybe peaking in early January. 

[raindancewx]

New JAMSTEC has trended the PDO more negative for Dec-Feb v. the prior run. Also has the warm waters north of the La Nina for the whole winter. Did not show that before.

The temperature pattern has gone to a cold north, warm south look for winter and spring in the US. It has WA/CA dry, with OR and the interior West near average, and the Midwest wet. SE is dry, NE is near average. The precip pattern is similar to the last run, just more amplified. Worth noting, it does not have the interior SW dry, so it probably thinks storms enter North America by the Baja at some point and head E/NE. Indian Ocean Dipole is supposed to remain negative through winter, which is also unusual for a La Nina. New run has the La Nina falling apart in March/April, as it did before, but overall has the Nina similar, only slightly weaker in Spring.

 

[raindancewx]

The SOI has collapsed to strongly negative values in the past few days - at a lag of a few days, this tends to precede some warming of Nino 3.4 if there is warm water around it.

SOI has been below -5 for each of the last four days for the first time since June 30 - July 3. Don't see an imminent reversal in the SOI either. Without help from the trades, some of the La Nina effects should relax a bit for a little while.

https://www.longpaddock.qld.gov.au/seasonalclimateoutlook/southernoscillationindex/soidatafiles/DailySOI1887-1989Base.txt

[AfewUniversesBelowNormal]

If nothing else, this could push us to weak El Nino by the Spring. La Nina looks secondary on map and imo the N Hemisphere pattern is being driven by other things.

[raindancewx]

Here is a look at temperature anomalies 1/6th of the way through winter. Will turn colder in the northern plains eventually, but with the warmth through today at least 1/6th weight, will be tough for that area to be super cold. The cold near the NV/ID/UT border is in line with my forecast, should return even if it gets wiped out some in the next few weeks.

[AfewUniversesBelowNormal]

This looks more like a pool, and gives the feeling of a natural +wave mid January, which correlates to monster-NAO and general warm N Hemisphere

[raindancewx]

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

 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

Looks like (maybe) the Nina peaked in Nino 1.2 - it was at -1.2, -1.3, and then -1.6 last week. Coldest waters seem to be slowly transferring west if you look at the trend in Nino 4.

[raindancewx]

This was hard to do, but December SSTs and December US temperature anomalies to date look a lot like a blend of 1954 (x2), 1988, 1995, 2014. I threw 2014 in there to dull the bill 1988 La Nina some, and to warm up the waters north of the La Nina.

[AfewUniversesBelowNormal]

Nice post, the analogs are very -PNA in the following months despite a cold pool in the PDO region. 

 

I also think looking at the La Nina now, that something similar to 2005-2006 or 2006-2007 may happen for the Winter. Warm waters above and below are suffocating the La Nina, signs of a warmer global pattern. 

[raindancewx]

What kind of severe season are you all expecting in Spring? Traditionally, the ring of heat from the upper Midwest to Washington state, north of colder anomalies near the Gulf Coast produces very wet Marches in the Southwest, but we'll have to see. The city hasn't had "average" rain since 2007..so its gotta happen eventually right?

These are the Decembers before my wettest ten Marches from 1931-2016 - its probably a ~70% match nationally by the time we finish December, with the anomalies in the NE/SW off (too far SE), likely from the relationship in Pacific/Atlantic temps being a bit different. The SSTAs from Dec in these years are like a mirror image of now.

[Paragon]

16 hours ago, AfewUniversesBelowNormal said:

Nice post, the analogs are very -PNA in the following months despite a cold pool in the PDO region. 

 

I also think looking at the La Nina now, that something similar to 2005-2006 or 2006-2007 may happen for the Winter. Warm waters above and below are suffocating the La Nina, signs of a warmer global pattern. 

Yes and the warmer pattern also leads to more moisture, therefore more rainfall/snowfall.

[AfewUniversesBelowNormal]

When you mention this I get the La Nina feel, although it may just be a time of very warm global temperatures. Because of what's happening now, La Nina is the highest chance to continue in the Spring, and I know this favors above average severe activity. 

[raindancewx]

The thing is, the worst severe seasons tend to be cold in the NW 1/4 of the country and hot in the SE 1/4 of the country. It's been pretty hot in the Northern Plains (+15 near ND/MT/Canada border) and Washington state this month, and it's been fairly average in the SE. I know people were calling for the cold NW/warm SE La Nina climatology for winter, but the heat for the Northern Plains is so intense already its going to be tough to wipe out by Feb 28, needs to be -3 to -4 the rest of the winter just to get to +0 in some places up there.

I had the Plains very warm in January in my outlook, so it makes sense to me, just a bit surprised on the timing of it, but getting the MJO right is always hard.

Dec 1973 & Dec 2010 were both quite cold in the places (northern plains) that are very warm now ahead of the super-outbreaks the following Springs. Haven't looked at other years though.

[raindancewx]

Tropical Tidbits is showing Nino 3.4, 3 and 4 all warming to some extent. We'll see what the weeklies show, they probably won't be out tomorrow since it is Christmas.

It will take a little bit, but those +3C to +4C waters are at the edge of Nino 4 / Nino 3.4 and may surface in Spring. Eastern 2/3 of Nino 3.4, and all of Nino 1.2 still looks very healthy, but when the warm water surfaces, would think changes in the trade winds start to push this back toward Neutral pretty quickly in Spring, possibly as soon as March.

[rolltide_130]

On 12/20/2017 at 8:38 PM, raindancewx said:

The thing is, the worst severe seasons tend to be cold in the NW 1/4 of the country and hot in the SE 1/4 of the country. It's been pretty hot in the Northern Plains (+15 near ND/MT/Canada border) and Washington state this month, and it's been fairly average in the SE. I know people were calling for the cold NW/warm SE La Nina climatology for winter, but the heat for the Northern Plains is so intense already its going to be tough to wipe out by Feb 28, needs to be -3 to -4 the rest of the winter just to get to +0 in some places up there.

I had the Plains very warm in January in my outlook, so it makes sense to me, just a bit surprised on the timing of it, but getting the MJO right is always hard.

Dec 1973 & Dec 2010 were both quite cold in the places (northern plains) that are very warm now ahead of the super-outbreaks the following Springs. Haven't looked at other years though.

 

2010 was a different instance as it was relatively cool and highly dynamic across the Southeast that winter. Some of the more southeast oriented folks have actually noted a very similar synoptic pattern to December 2010 so there is some concern around here for a potentially active spring. 

[AfewUniversesBelowNormal]

It's a well established La Nina at this point that has the signature of many post-1998 La Nina's, and should effect the pattern Jan-Feb alike (warm everywhere). 

[raindancewx]

I am looking forward to seeing what the huge -SOI crash is going to do. The Consonant Chaos guys argue big SOI changes from a prevailing base state take three weeks to show up, and its been in the -2 to -20 zone every day since December 11th. 

The 30-day SOI is down to +1.25, after +10.4 in November, and +10.64 in October. November 26-30 finished at +15 to +30, so its an even larger drop against that context, was like a Super Nina for a few days. Was very positive in early December too.

In retrospect, the big +SOI Octobers are a strong signal for a hot TX/NM in November, and lower SOI in December (which we're seeing) is pretty strongly correlated to a warm up in the Northwest, NE, and Great Lakes in January. We'll see where the SOI ends up in a few days.

 

 

 

 

[raindancewx]

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

[AfewUniversesBelowNormal]

DJF is Winter, so far we are at -0.9c

[raindancewx]