2019-20 WINTER HEADLINES
NOTE: Our first guess region by region snowfall forecast for 2019-20 is at the bottom of this post. ***
PAST SNOWFALL OUTLOOK YEARS
Before we start, here’s a look at past snowfall outlooks.
I don’t hide anything and I’ll be the first to tell you if I’m wrong. Out of the past six years that we’ve been doing winter outlooks, we’ve only had ONE year where the winter outlook failed, which was 2016-17. This was the “DC snow hole” winter.
As you can see, I have my own point system and I am very strict on myself when I am much lower than forecast. To be fair, there are two grades. The top grade DOES NOT count the forecasts where snowfall was ABOVE the forecast. The bottom grade combines both. Roughly 75 percent of our Virginia Weather Network/Action followers are snow lovers and are happen when they get more snow than predicted. However, I want to be fair across the board, and as you can see, we do pretty well.
I put A LOT of time and effort into these forecasts and I don’t just throw numbers out there for “hype”. We have built a fan base and following where people trust us try very hard to give everyone the best forecasts and outlooks possible. NO forecast, anywhere, will be perfect. They all have their flaws and good sides.
SNOW COVER ACROSS EURASIA & SEA ICE
We talk about this a lot. There is a big connection in regards to how much snow cover there is across Eurasia and sea ice across the Northern Hemisphere. The more snow that builds up in October and November in Eurasia, and the higher the sea ice in the Northern Hemisphere, the more cold it gets. With strong fronts and storms, and areas of low pressure (one in Siberia, and the other in North America, or known as the “Polar Vortex”,) this can bring polar cold from Siberia to the North Pole, straight down into the United States. Therefore, for snow lovers, you want to see a gradual increase in Eurasia Snow cover.
North Atlantic Oscillation
One MAJOR thing that lacked last year was a negative NAO. However, it has shown up over the past few months.
In the diagram above, you an see how the jet stream dips from the Plains and Midwest into the Southeast. High pressure near Greenland is what helps to guide storms along the East Coast.
When the NAO is positive, there’s no high pressure over Greenland, which creates a fast zonal jet stream. Storms can easily (and usually) move off the coast and out to sea.
We feel the North Atlantic Oscillation will be in many NEGATIVE phases for the upcoming winter. Many reasons and factors as to WHY is explained below.
ENSO & SEA SURFACE TEMPERATURES
This winter, we will have a “La Nada” or “Neutral” conditions. However, some models show a very weak El Nino developing. This is something that will need to be monitored, as this could open the door to a more active subtropical jet stream, with more storms across the Southern United States. With colder air in place, this could mean some big time winter storms.
Current Sea Surface Temperatures show a large pool of warmer water across the Central and Eastern Pacific. There appears to be two areas of warmth, one “blob” focused off the Alaskan coast and another just east of Hawaii. If the warmer blob near Alaska were to take over, then we would have higher odds of seeing periodic shots of colder air across the Eastern U.S. Colder waters off the coast of Florida and in the Bahamas is likely from the impacts of Hurricane Dorian. We can also see a “mix” of cooler and warmer waters near the Equatorial Pacific, but are indeed WARMING. There will continue to be up and down spikes through the fall and winter.
Another thing to note are the warmer ocean temperatures along the East Coast. If this continues, any storm that develops off the coast will have more “fuel.” Colder waters further south could possibly be contributed by minimum solar sunspot activity.
SOLAR CYCLE SUNSPOT ACTIVITY
Our last “severe” winter was back in 2009-10. If you look at the graph below, you can see that 2009-10 reached the minimum solar cycle. Solar sunspot activity plays a huge rule in patterns across the Northern Hemisphere. In fact, many severe winters occurred during minimum solar cycles and favors stormy and cold weather across the Eastern United States, due to ridging in Greenland. Many severe winters during the mid 1960’s, late 1970’s, mid 1980’s, mid 1990’s, and 2009-10, all occurred when the solar cycle reached it’s minimum.
As of September 9, we are expected to reach a minimum solar cycle during the upcoming 2019-20 winter season.
QBO (Quasi-biennial Oscillation)
The Quasi Biennial Oscillation refers to phases of more westerly or easterly winds in the stratosphere over the Tropics. Easterly phases are typically associated with a weaker winter time stratospheric polar vortex (and a better likelihood of sudden stratospheric warming events, leading to potentially periods of deep –AO blocking), while westerly phases tend to be associated with a stronger winter time stratospheric polar vortex (and a lower likelihood of the vortex getting disrupted in winter, potentially leading to periods of +AO conditions). There are exceptions to the rule, but the correlation is fairly well understood.
The following map is from Meteorologist David Tolleris, from WxRisk.com. He has always always been intrigued by the QBO and got me interested and learning about it several years ago. It has it’s flaws (like many things do, such as models, etc.,) but its a really good tool to use to help determine what will happen in the coming months. It’s important to note that just because the QBO falls into negative numbers does not always necessarily mean the winter will be cold or snowy, due to other large scale teleconnections that play important roles. While it’s NEVER a good idea to lean on strictly the QBO, I would still say that it has had at least 65 percent accuracy in our outlooks.
In many of the analogs below with QBO values in the -10 to -15 range shown below, you get a trough in the west, blocking (-NAO) and very cold air across the Eastern U.S. A cross-polar flow is found in many of these analogs, meaning a direct connection from the extreme cold from Siberia, funneling right into Canada and the Eastern U.S.