ESCOWare’ Nov. through Mar. 2017-18 Temperature Anomaly Winter Forecast

Summer 2017 Recap

ian-palao.jpgThe ESCO Advisors Summer (May-Sep) Forecast was a mixed-bag. Our Summer forecast is in fig. 1 while the actuals are in fig. 2. We nailed the heat in the Inter-Mountain West. Had the right idea about the cold in the northern tier, just was too far west with it. Although you can see some warm anomalies beginning to emerge, the biggest “misses” were in the south/central Plains and the Northeast, where the forecasted heat never fully materialized.
In the Tropics, our forecast of an active season (14 named storms, 9 hurricanes, 3 major) has surely come to fruition as we have seen 15 named storms, 9 hurricanes, and 5 majors through early October.
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Winter 2017-18 Analysis
As we head into Winter (November-March), we need to analyze the potential drivers of the seasonal climate. We tend to view these drivers in three categories: jet stream set-up, cold pool, and landmass modification.
A cold US winter can only exist because of the transport of Arctic air into the lower 48.  The transporting mechanism is the jet stream. And, during the Northern Hemisphere winter, the biggest determinant of the placement and strength of the jet stream is the condition of the Southern Oscillation…El Nino, La Nina, or “neutral”. Currently, we are under a “La Nina Watch”, with a 60% chance that La Nina develops. Typically, a La Nina will push the northern jet into the Plains and Midwest, opening the door for cold air intrusion. 
Let’s back the train up for a minute and talk about the “cold pool”. There needs to be sufficient cold air gathered in the Arctic for the jet stream to lead south. As I type this in early October, you can see in fig. 3 that the areal coverage of sea ice is far below the 20-year average. One thing to note is that it is significantly above the historical minimum. Additionally, fig. 4 shows that ice-coverage in the southern Arctic is very close to normal. This leads us to believe that “early season” extreme cold will be limited.
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Lastly, we need to look at landmass modification factors, namely soil moisture. Dry soil will lead to colder conditions than “wet” soil. That said, of the three categories that we analyze to develop our winter forecast, soil moisture is the one that is most variable in that it can change the quickest. So, what is written today may not hold for tomorrow, much less in a few months. Currently (early October), soil moisture is lacking in a few areas, mainly the northern Plains, western Midwest down to TX, coastal New England, and a few spotty locations in the Mid-Atlantic (fig. 5).  Please note that for the deregulated electric space, “moderate” is the worst drought category currently seen. But this can easily be erased with Fall and/or early Winter storms.
Winter 2017-18 Forecast
Typically, we forecast for the entire 5-month winter period in aggregate. For this winter season, we are seeing a distinct bimodal pattern and have created two distinct forecasts, Nov-Dec and Jan-Mar, to highlight the differences. Hopefully, this will provide you with even more detail in which to develop a hedging strategy. To create one forecast would lose the needed temporal granularity we think will be the differentiating factor this winter. 
We believe that the Nov-Dec period (fig 6) will be characterized by cold anomalies in the West and warm anomalies east of the Rockies, centered on the Midwest and Ohio Valley. There may be a few back-door cold fronts passing through New England but we do not believe this will be the “norm”.
It is during the Jan-Mar (fig 7) period that things may get interesting, in our opinion. It is here that we believe La Nina will show its influence.  While we depict most of the country as being colder-than-normal to some degree, the focus of the cold will be in northern tier from the Plains, through the Midwest, and into the northern reaches of the Mid-Atlantic and New England. The potential for polar vortices (the notorious “Arctic Blasts”) should be rather high during these months. The uncertainty (and risk to your companies) lies with the frequency and duration of the events. Those will have to be prepared for on a case-by-case basis. We will do our best to give you advanced notice when we see the blasts’ signature in the numerical weather prediction model output.
Of course, the main risk to our forecast is that the cool latter-half of the period does not materialize. A secondary risk would be for the focus of the cold to shift eastward. At this point, we believe the latter to have a higher probability of occurrence than the former as La Nina winters tend to have a distinct cool anomaly…..the question being the focal point of entry into the US.

NOTE: ESCOWare® and ESCO Advisors™ provide this information as a courtesy to enhance the risk management process and are not responsible for the accuracy of this forecast and/or actions taken as a result of this forecast information.
To learn more about the ESCOWare® suite of software solutions, please contact Irv Lebovics at 203-456-1833 or visit
2018-04-24T15:56:15+00:00 October 19th, 2017|ESCO News, Weather & Risk, Winter Forecast|