September 9th, 2014
Econintersect Climate and Weather Update, 8 September 2014
Written by Sig Silber
Fall is coming early as least to the eastern half of the Lower 48. El Nino is still a tease. The Southwest Monsoon continues to please - unless you live in Phoenix.
Not all El Ninos are the same so I go into that in some detail plus discuss ocean warming. The El Nino is occuring but slower than predicted by the IPCC models. What is that telling us? Today I will continue to provide more data on ocean warming which I began to introduce last week. It is a complicated subject. And all of this will have economic impacts.
First let's talk about the 6 - 14 day outlook issued today September 8 for the U.S.
I am only showing the "second week" namely the day 8 -14 outlook. The first week can be found in Part II of my report but 8 - 14 days covers most of the 6 - 14 day period.
8 - 14 Day Outlook
Notice that with respect to temperature, there is a real divide between the West and the East. With respect to precipitation, the divide is North to South. Some explanation of this might be found in the "analogs" discussed below. The local forecasters are not as convinced as NOAA or more specifically the National Weather Service Climate Prediction Center about the above climatology precipitation in the Southwest.
Last week I introduced the "Analogs" which NOAA provides related to the 5 day period centered on 3 days ago and the 7 day period centered on 4 days ago. "Analog" means that the weather pattern then resembles the recent weather pattern and was used in some way to predict the 6 - 14 day Outlook.
What if anything are they telling us today?
|1956 September 13||La Nina||-||Neutral|
|1957 September 16||El Nino||+||Neutral||PDO had just flipped|
|1980 September 15||Neutral||+||-|
|1982 August 24
||+||-||Very strong LATE El Nino
|1982 August 25
||Very strong LATE El Nino
|1990 September 8
|1990 September 9
|1993 August 31||Neutral||+||-|
|1993 September 1
This analog analysis seems to reflect a shift in the phase of our ocean cycles from PDO-/AMO+ which is the opposite of the pattern that has been in place this first part of the 21st Century. Please refer to the McCabe et al maps in the second page of this report on the impact of this change on drought patterns in the U.S. The 1982 analogs are very interesting.
El Nino Update.`
From today's NOAA Report.
The bottom of this Hovmoller diagram represents the most recent readings. It looks less warm in the Eastern Pacific but the hole of no anomalies in the Nino 3.4 area that was blue last week has filled in due to the Kelvin Wave so to me this looks like no progress towards an El Nino. On the Equator, the ocean meets the land at about 80°W so the right hand part of the graphic shows the area where we would expect to see significant warming warming during an El Nino.
Of course we would not expect to see any blue in the Eastern Pacific during the development of an El Nino. So this Hovmoller graphic seems to be showing that either nothing much is happening or the process is going backwards. It is consistent with the theory that we had an incipient El Nino that failed and some are reading the tea leaves and seeing another one developing but I am not seeing it yet.
This shows the basis for thinking that the dying El Nino might be revived. You can see the Kelvin Wave which is not as robust as the one earlier this year but still a potent Kelvin Wave moving across the Pacific towards Ecuador. If you look at the color coding you can see that as this moves into the Nino 3.4 area it will record as an El Nino but barely.
And now another part of the equation.
This is the part that is driving meteorologists to drink. If I am reading this correctly, and I think I am the, winds are not cooperating. The Easterlies are not relaxing but strengthening thus blowing the incipient El Nino back towards the Western Pacific. That is probably the main reason the models are continually lowering their estimate of the strength and probability of this El Nino. I do not think that anyone knows why this Southern Oscillation (SO) component of the El Nino is not cooperating. You can have an El Nino without the SO cooperating but one would not expect that to be a very robust or long-lived El Nino.
But this can change quickly which is why some of the models continue to predict an El Nino this winter. Actually this winter is here and the El Nino is not. Some El Ninos including the 1982/1983 El Nino are late for the party and that El Nino was very powerful. So although I am very skeptical about this El Nino the game is not over. We have to wait and watch to see how it develops.
Australia will issue an update tomorrow. But since their proprietary model results are already available on their web page I do not expect any significant change in the way of increased enthusiasm for this El Nino. If I am incorrect about that, I will post their update on the Permanent Page which is Page II of this report and which you can get to by clicking at the end of this article where it says "click here for the Econointersect Weather and Climate Page".
And from the CPC/IRI based out of Columbia University issued Sept 4:
Notice by April-May-June 2015 the probability of Neutral Conditions exceeds the probability of El Nino Conditions. So according to those involved in this analysis it will be a fairly short El Nino.
But what kind of an El Nino will it be? Not all El Nino's are alike and in recent years the distinction between traditional or canonical (true to form) El Ninos and Central Pacific El Nino's often called El Nino Modoki has become increasingly clear. In Japan they are forecasting an El Nino this winter followed by an El Nino Modoki the subsequent winter. This becomes important because the impacts of each type of El Nino on weather worldwide is very different.
This is illustrated in the following maps:
Starting with surface temperature:
|Traditional El Nino
||El Nino Modoki|
And now considering precipitation
|Traditional El Nino
||El Nino Modoki|
You can find these graphics and more information here.
And below is a breakdown of precipitation anomalies from climatology by important parts of .the world very impacted by the Modoki form of El Nino. You can find more information on this here.
So there is a big difference in the differential impact on weather yet BOTH WILL REGISTER AS AN EL NINO ON THE ONI INDEX.
Some think a Modoki is some sort of strange thing. To me it looks like a Modoki is simply an El Nino that did not fully make it to Ecuador or after reaching Ecuador has taken its sweet time getting all the way back to the Western Pacific Warm Pool. From a weather perspective, with a Modoki you end up with two Walker Cells. So you have a lot of precipitation in the Central Pacific. Notice how the impact on Japan and the Western U.S. varies between a Canonical El Nino and an El Nino Modoki.
Most believe the El Ninos of 2002/2003 and 2004/2005 were actually of the Modoki variety and you can see that in the winter precipitation data for New Mexico and Rio Grande Stream Flow. The below may be a Bob Tisdale compilation but it is based on the Ashoc formula which is generally recognized as the way of identifying a Modoki.
The 2009/2010 El Nino was also a Modoki, So you see what you read in the news may not be very useful. I do not believe that many TV and Radio station weather people (many of whom are not even meteorologists but simply actors) understand the difference between these two types of El Nino's. It is fairly recent knowledge.
To make things even more complicated, some believe there are two kinds of El Nino Modoki's and this is described here.
I am not going to go into the details this evening on how the following breakdown was developed, but based on these authors we have since 1950 had sixteen El Ninos broken down as follows:
|Traditional or Canonical El Nino||Modoki Type I||Modoki Type II|
Although both the researchers work for NOAA and were based in Miami Florida when they did this research, they seem to have used the Chinese System of identifying an El Nino i.e. focusing on Nino 3.0 rather than Nino 3.4. Nino 3.0 is the eastern part of Nino 3.4. This may explain the slight difference between their characterizations and that of Bob Tisdale and NOAA in that these Chinese authors do not seem to recognize 2006/2007 as any kind of El Nino. It barely met the ONI criteria of five consecutive overlapping three month periods with the ONI being 0.5 or higher and in the first period it was exactly 0.5 so it may very well have not recorded as an El Nino when Nino3.0 was used as the criteria rather than Nino 3.4 which is a bit further west.
That does not seem to be a good explanation to me but this was 'barely" an El Nino and any slight change in criteria could rule it out. Tisdale categorized it as a canonical El Nino and when I look at the precipitation situation in New Mexico and the values of the PDO Index it seems to me that this was more of a relief between two La Nina events, one of which was quite strong, rather than an El Nino so I think the characterization in the above table is probably more on target than the NOAA characterization although it is a borderline case.
But the general conclusion is that since the PDO turned negative in 1998 we may not have had a traditional or what is called technically a canonical El Nino. I do not have the time right now to match the above categorization of Modoki I and II to precipitation patterns in the U.S. The referenced authors focused on the Western Pacific mainly China.
It tells me that we have to be very careful about how we relate to something called an El Nino since there are at least three varieties and each has a different impact on Global Weather.
A very good reference to the literature on ENSO can be found here. It is an amazing document and the discussion on Global Warming is very interesting. There is no consensus on how Global Warming has or will impact ENSO although many think it does, But they disagree on how!
All of this is very important for many reasons which technically boil down to how the overall behavior of the Pacific and Tropical Pacific are interrelated. Currently we decompose the Pacific into the Pacific north of the Equator which we describe by one index called the PDO and the Tropical Pacific which we describe by one index called the ONI. But from what I read (and I have in this article provided the links) it probably is less than fully productive to look at things the way we have been looking at things and I anticipate that more people will be looking at things differently.
Back to Oceans
I presented this chart last week.
From Japan Met Global Environment and Marine Department Report
"The annual mean annual global average sea surface temperature in 2013 was +0.13°C above the 1981-2010 average, making it the 2nd highest since 1891. The long-term trend of the global average sea surface temperature for 1891-2013 was about 0.51°C per century. Although positive anomalies above the long-term trend have frequently been observed since the late 1990s, the global average sea surface temperature has generally remained at similar levels since the early 2000s."
Here is another more short-term oriented chart.
Notice the spike in August. This appears to be due to a rise in the SST of the Northern Pacific. Bob Tisdale attributes this to the anomalous blocking pattern over Alaska and indeed we did have and continue to have colder than climatology temperatures in the Center of North America. So this could be a short-term balancing of heat between land and ocean but I am not so sure. I do not think this is the signature of Global Warming but it may well be related to the changes taking place in the Pacific possibly related to El Nino or the PDO. Not sure I will get into this tonight but there are variations of El Nino Modoki that are consistent with this pattern.
A Few Thoughts on the North American Monsoon
The following map is the mid-atmosphere 7-Day chart rather than the surface highs and lows and weather features. In some cases it provides a clearer and less confusing picture as it shows the major pressure gradients and the 500 MB chart often is a good guide to conditions at the surface.
Notice the "Four Corner's High"as of today's forecast i.e. September 8, for a week from now (the graphic is about Day 7) appears to be in the Gulf of Mexico where it still can create favorable conditions for warm moist air to move up from Mexico into the Southwest. I usually draw a clockwise circle around this High to help imagine how it might impact overall circulation. This may be the last time I show this graphic until next summer as the Southwest Monsoon is about to go on vacation. But tropical storms in the Pacific may extend its life an additional week. The Monsoon may continue to impact Mexico after it no longer is able to significantly impact the U.S. Southwest.
- NOAA and other agency graphics (including international agencies) that auto update. So this includes both short term- and seasonal "updates". It will ALWAYS be up to date even if my commentary on the graphics is not. I update my commentary when it seems necessary and certainly every Monday but some of these graphics auto update every six hours.
- Economic and other Impacts of major weather events. Not sure there is any other place to obtain this information consistently other than very specialized subscription services.
- Information on Climate Cycles both those which are fairly short term i.e. less than a decade in duration and multi-decadal cycles.
- Economic and other Impacts of those Climate Cycles which are referred to by the IPCC as Internal Variability as opposed to secular Climate Change which is always in the same direction. Again I am not sure if there is another source for this information where it is pulled together in one place as I have.
- Information on Anthropogenic Global Warming science i.e. the secular change in our climate that overlays both short term weather and historical climate cycles as well as black swan events like volcanic eruptions. I prefer to call this Global Warming as it is the warming that triggers the other changes.
- Economic and other Impacts of Global Warming. The IPCC AR5 WG2 attempts to describe and quantify these and I have some excerpts from their report. Over time I will go beyond their report.
For now this is all in one article which may be a little difficult to navigate but that will soon change and the information will be accessed easily by topic.