I sat in on another winter weather forecast webinar earlier this week, this time from the company BAMWx.com. I sat in on a similar webinar a few weeks back from MDA, and you can read an account of that forecast at this link.
BAM’s outlook for the winter is very similar to what MDA shared with their preliminary forecasts.
Keep in mind this is a preliminary forecast which takes into account atmospheric drivers that are in place right now and/or are expected to be in place based upon several factors. Here are some of the factors BAM took into account for their forecast:
Let me ‘Gumpsplain’ some of these things for you…as in Forest Gump, as in “Momma always had a way of explaining things so that I could understand they’um.”
Negative QBO: That can lead to high latitude blocking, which is a good cold signal
Low Solar Activity: Fewer sunspots, we are near the low of the sunspot cycle, or the minimum, but we may experience the effects of that in the coming two winters, not this one. That is a good thing for our industry, by the way.
Pacific Jet: It was strong last year and really cooled the waters off the western coast of Alaska, which set up low pressure in an area where we want high pressure, as well as that jet stream being so strong that it created a west to east (zonal) flow across the CONUS (Continental United States) and hence, a lot of warmth.
Now, for their analog years, which are the years they have identified as having had a similar weather set up to what they are presently observing:
The year listed is the November-December of that winter. For instance, the first year listed is 1950, so that would be the winter of 1950-1951.
Here is how my Jan-Feb combined heating degree days for the listed analog years played out, based on HDD data I have compiled from the annual averages dating back to 1995, or 23 years, and taking measurements from 19 cities across the country. This is NOT any sort of scientific observation, just more interesting to me than anything else:
1995: 2.85% colder than the 23 year average
2000: 3.75% colder than the average
2005: 12.27% warmer than the average
2007: 5.20% colder than the average
2011: 10.28% warmer than the average (at the time, warmest on record for Cleveland)
I don’t have any data on the winters before these, but here are some things I found on the google machine:
Winter of 1983-1984: ‘A Season of Strong Blocking and Severe Cold in North America
1988-1989: Chicago Dec-Jan-Feb temps were near their 100+ year averages.
1983-1984: Late December, $2 billion in damage to Florida crops, -50 in Williston, ND, Sioux Falls, SD remained below zero from the morning of December 16th through Christmas Day, 125 daily low records were broken on Christmas Day, and the high in Tampa on that day in 1983 was 38 degrees.
Analogs are not answers, but they are used in creating long range ideas…now, moving forward…
The atmosphere is showing a trend toward a mild La Nina event for this winter, and BAM believes this year, it make stick. You may recall that we had a La Nina state entering last winter, and we had some very cold air in December, but the La Nina faded and a more El Nino-like background state took hold for January and February.
Here are some images that show (from left to right) what a La Nina year typically looks like, the middle image shows the same, while the right image shows average precipitation.
Next, here is what BAM is going with on their preliminary forecast, Dec-Jan-Feb:
Here is what the Heating Degree Days look like for this winer (Dec-Jan-Feb) compared to last year as well as the 10 & 30 year averages:
You will note a slightly colder expectation than the 10 and 30 year averages, and nearly 16% colder than last winter. The 16% number is nearly identical to what MDA showed for their forecast projection for this winter as well.
This last slide shows last year compared to this year’s projection, with the slide in the lower right showing a shaded area over the Midwest and Ohio Valley that shows ‘Colder Risks This Winter’ with the southern tier of the CONUS shaded with ‘Similar Warm Risks to Last Winter’. Don’t be alarmed by the red map top center, as that is is LAST WINTER.
Finally, in case you might have missed any of the three winter write ups I have done, here are the links..you obviously don’t need the link for the BAM write up, as you are reading it right now:
After reviewing these three preliminary forecasts, you will note the general ideas are very, very similar.