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AfewUniversesBelowNormal

Weak La Nina Winter

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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.

6deCHdv.png

 

 

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.

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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

 

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December conditions in Nino 3.4, Nino 3, Nino 1.2 were a good match for a blend of 1967, 2005, 2005, 2007. If you blend those years, it isn't a terrible match nationally for December (Nino 1.2, 3.4, 4 is better for national conditions anyway), and you have a lot of pretty warm waters by the US.

Winter 1967-68 was cooler than normal in 3.4, but very cold in Nino 1.2, so it had a very positive Modoki value, which is unusual in years when Nino 3.4 is cold. The 2017-18 imbalance between 3.4 and 1.2 isn't as great as that year, and diminishing somewhat but its useful for blending. I like that blend because something about it is similar in the Atlantic too, you had a major hurricane hit Texas in 1967, the big hurricane season in 2005, and then 2007 had similar sea-ice in Summer to this year. When Beulah hit in 1967, parts of TX had 27 inches of rain (half of Harvey in half the time), and I think super heavy rains in TX in the Summer have some kind of effect on the strength of the subtropical ridge for a long time.

This is on ERSST V.5 - on different data sets 1967 (x5), 1975 (x1), 2005 (x1), 2007 (x3) works pretty well too.

Dec Nino 3.4 Nino 3 Nino 1.2
1967 25.95 23.99 20.97
2005 25.68 24.00 21.89
2007 25.01 23.57 21.15
2005 25.68 24.00 21.89
Mean 25.58 23.89 21.48
2017 25.62 24.02 21.44

I've been looking hard at Spring 1951 too - the dryness (0.04" in Oct-Dec 2017 here, 0.01" in Oct-Dec 1950) with a very hot Nov+Dec here is similar to 1950. If you want to see a batsh-t crazy pattern, look at March 1951.

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1932-33 had similar dryness nationally to this winter, although it was much colder in the West (it was a volcanic-cold neutral). I'm not surprised that 90% of the lower-48 is drier than normal so far. We're actually drier than 1932-33 so far, which is not good as that was one of the winters that triggered the Dust Bowl. Still expecting some turn around in the West toward wetter conditions over the second half of winter. California is actually 5"+ below normal in places so far (3mm/day * 45 days).

jVPOesc.png

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On 1/18/2018 at 3:51 AM, raindancewx said:

1932-33 had similar dryness nationally to this winter, although it was much colder in the West (it was a volcanic-cold neutral). I'm not surprised that 90% of the lower-48 is drier than normal so far. We're actually drier than 1932-33 so far, which is not good as that was one of the winters that triggered the Dust Bowl. Still expecting some turn around in the West toward wetter conditions over the second half of winter. California is actually 5"+ below normal in places so far (3mm/day * 45 days).

jVPOesc.png

There is a bit of correlation, but a lot of the east doesn't match up, and with the current pattern change, things should start to improve out west and in the midwest as well.

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Yep. The winter isn't over yet either, but for an ancient year, its not terrible. I only gave it 1/10th weight anyway.

The main similarity in that year to this year is it has the warm anomalies in the Atlantic north of the cold anomalies in the Atlantic, which has some relationship to precipitation in the West.

cdas-sflux_ssta_global_1.png

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18 minutes ago, AfewUniversesBelowNormal said:

The La Nina is falling apart in the west. it may cold pulse again but it will less than before and followed by a warm up probably above 0.0

I would be careful here, the SOI shot through the roof over the last week, would be indicative of strengthening not weakening with the La Nina.

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Using the 1950-2000 base period from the extended data set NOAA has for Nino 3.4/Nino 1.2, I think NDJ ends up around -0.80C in Nino 3.4, Nino 1.2 around -1.10C.

Last year, against that base period was -0.49C in 3.4, and +0.09C in NDJ, and both warmed a lot in DJF.

I'm hoping we get some last second warming in both - I find hand-blending Nino 1.2, Nino 3.4, for NDJ, with annualized solar analogs produces around a 0.65-r-squared relationship with Spring precipitation in my area. Super dry Springs tend to be very cold in Nino 1.2, Nino 3.4, with low solar activity. The relationship is based on 1987-2016, the further back you go the harder it gets to recreate years. The blend I'm using (-0.8C, -1.1C, 18 sunspots July-Jun) implies 0.96" precipitation here for March-May, which is close to 40% below normal.

My hunch at this point is Nino 3 stays in La Nina conditions the longest, with the event rotting away on both sides pretty rapidly in March/April. 

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January 2018 MJO looks like a blend of 1978, 1986, 1989, 1990 to me. Those years overall had a start in phase two, with February starting around 6/7, and they had no "neutral" MJO conditions. The timing of the phases is too early in those years, but if you add a week, its pretty spot on nationally. January looks pretty warm nationally on the blend, suspect it won't be too far off for Jan 7-Feb 5 or so. I gave Jan 1986 the most weight, as it was a near-Nina in DJF, with low solar, and started in phase two in January. The low-solar years seem to have slower MJO propagation, so the speed is most similar to 1986 too.

ArNLqeb.png

DUH9E_CV4AAeFH2.jpg

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Weakening
                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
 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
 17JAN2018     23.9-0.6     24.7-0.9     26.0-0.6     27.9-0.3

 

GgoUXXp.png

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