It seems like it. I’m assuming that a lower amplitude wave would be more susceptible to being offset by other factors than a higher amped one (tell me if that is wrong). That said, I’m still a little murky on why we don’t just mainly look at the mjo phase/prog in winter (when it’s strong) and minimize other variables, since it seems to be the main driver. Or is it only the main driver during certain atmospheric states? I don’t know if I’m being clear. I guess what I’m asking is that in order to use it properly as a tool, you can’t just look at it only at the expense of other things. But the general posting public, myself included, tend to do that (e.g. hoping for it to go into phase 8, so that it gets cold) and maybe not considering other conditions that may be present to offset it.
It certainly seems to be a significant driver right now, and I guess that should continue, especially if it remains strong. But I’m only acknowledging that because people smarter than me say so — not because I have deduced it to be so. I don’t know enough about what else might pop up to counter it. But if, I mean when, we get to the cold phases, if the pattern doesn’t respond, I’m going to be scratching my head and will probably ask the question again.
Anyway, thanks to you and Webber and the others who post about it and help us better understand it.
Regardless, very low amp (inside the circle) of the colder phases in Jan 1975-2014 phases has averaged much colder in the SE US than outside the circle in the cold phases. This is based on 40 Jans of objective data, not a small sample. See my blog post on this if interested:
https://blog.southernwx.com/2017/01...phase-inside-the-left-side-of-circle-coldest/
Actually, inside the circle for each of the 8 phases averaged colder than outside for each respective phase in Jan. This doesn’t mean there weren’t any inside the left side of circle that were warm and it doesn’t mean there weren’t any well outside that were cold because there are always exceptions. My study looked at averages. See the diagram below and you’ll see that every phase inside the circle was colder than each respective outside phase.
If we’re just looking at El Niño, does that relationship still hold for Jan? I didn’t break the main study by ENSO because that would result in much smaller sample sizes for each phase. However, I just now did it and
the idea not only held but it is even more pronounced! I found 10 El Niño cases for which there were at least a handful of days either inside/near the left half of the COD or in low amp 8 meaning I had to leave out 1980, 1987, 1992, 1995, and 2010.
1.
Jan 1977 (coldest month on record):
KATL was 16 below normal (
-16) when the MJO was near or inside the left half of the COD 1/17-30 vs a not as cold -12 the rest of the month, when it was still in mainly non-warm locations either inside the right half of COD or low amp just outside it in 2, 3 ,6, and 7:
http://www.bom.gov.au/climate/mjo/graphics/archive/MJO_phase/197701.phase.90days.gif
2.
Jan 1978:
When the MJO was either inside phases 7-8-1 or barely outside phase 1, which happened Jan 5-12, KATL was
-11 vs a just about as cold -10 the rest of the month:
http://www.bom.gov.au/climate/mjo/graphics/archive/MJO_phase/197801.phase.90days.gif
3.
Jan 1983:
Jan 15-20 was
-9 when the MJO was either or inside COD 7-8-1 or barely outside in 1 whereas the rest of the month averaged a much warmer -1:
http://www.bom.gov.au/climate/mjo/graphics/archive/MJO_phase/198301.phase.90days.gif
4.
Jan 1988:
KATL was during Jan 1-15
-8 when MJO was just either just outside COD phase 8 or inside COD phases 7-8-1-2 vs a much warmer 0 for the rest of the month, when it was outside COD in phases 2-3 just about every day:
http://www.bom.gov.au/climate/mjo/graphics/archive/MJO_phase/198801.phase.90days.gif
5.
Jan 1998:
During 1/23-31, when the MJO was either inside 7-8 or barely outside in 1, KATL was
-1 vs a much warmer +4 the rest of the month
http://www.bom.gov.au/climate/mjo/graphics/archive/MJO_phase/199801.phase.90days.gif
6.
Jan 2003:
During 1/13-31, when the MJO was just about every day either inside the left half of the circle or barely outside in 8, KATL was
-6 vs a much warmer 0 during 1/1-12 when the MJO was in low amp 5-6:
http://www.bom.gov.au/climate/mjo/graphics/archive/MJO_phase/200301.phase.90days.gif
7.
Jan 2005:
Jan 22-5, when the MJO was either inside the circle in 7-8 or barely outside in 8, was
-7 in a month that outside of those days was a much warmer +5:
http://www.bom.gov.au/climate/mjo/graphics/archive/MJO_phase/200501.phase.90days.gif
8.
Jan 2007:
Jan 18-25, when the MJO was inside the circle phase 7, was
-2 whereas the rest of the month was a much warmer +4:
http://www.bom.gov.au/climate/mjo/graphics/archive/MJO_phase/200701.phase.90days.gif
9.
Jan 2015:
Just outside COD phase 8 or inside 7-8, which was the case 1/23-7, KATL was
-1 vs 0 the rest of Jan. So, still barely colder though almost a wash this time:
http://www.bom.gov.au/climate/mjo/graphics/archive/MJO_phase/201501.phase.90days.gif
10.
Jan 2016:
It was near or inside the COD phases 2-3 Jan 20-25, when KATL was
-5 vs a much warmer 0 of the rest of the month:
http://www.bom.gov.au/climate/mjo/graphics/archive/MJO_phase/201601.phase.90days.gif
Analysis of the 10 analyzed Nino Jans:
A. KATL averaged a very cold -7.5 during the 98 days of Nino Jans when on/inside COD or low amp 8 vs -2 for the same for non-Nino Jans. So, if anything, the idea of being coldest on average when inside/low amp left is actually stronger when in a Nino!
B. For these 10 Nino Jans, compare this -7.5 with near 0 for the other days. In 8 of these 10 months, the inside left COD/low amp 8 was much colder than the rest of the month and barely colder for the other 2 Jans. It was never warmer.
C.
Summarizing, the 10 analyzed Nino Jan periods at ATL were -16, -11, -9, -8, -1, -6, -7, -1, -2, -5 vs normal. So, none were warmer than normal and 7 were significantly colder than normal.
Conclusion:
For El Nino Jans, the coldest position to be in MJOwise on average for the SE US having been inside the left half of the circle or just outside left especially in phase 8 is more pronounced than for non-Nino Jans! So, whereas there are always exceptions for these kinds of analyses,
the best chance for the SE US to have a sustained period of very cold this month would appear to me to be when the MJO is on the left side (7/8/1/2) either within or near the COD or a little further outside mainly in 8. That being said, this doesn't mean it can't be very cold when the MJO is elsewhere, especially in the higher amp of the left phases (7/8/1/2).
