2017-2018 Winter Weather Outlook From Fox 21’s Weather Team
Nov 13, 2017 09:27AM
By Brittney Merlot from Fox 21 Local News November 12, 2017
Watch the video forecast for the upcoming winter by following this link.
Part of keeping you prepared for any winter weather situation is being informed about what is expected to come. That is one mission the National Weather Service and us here at FOX strive for…
“During winter we have issued different types of advisories and warnings to let people know what’s going to happen and it could get kind of confusing with all these different types of products. So we are kind of lumping them into one more concise product”
The National Weather Service is simplifying terminology for winter weather warnings and advisories.
“In the past we would have snow advisories, blowing snow advisories, freezing rain advisories, freezing drizzle advisories….”
Now we simply have three categories, watches, advisories, and warnings, eliminating lake effect snow.
So a winter weather advisory means to take caution from a risk of minor snow, sleet, or freezing rain.
While a winter storm watch or warning will now include lake effect snow… As well as specific warnings for ice storms or blizzards.
“They will still get the information, but it will reduce confusion as to what is going to happen”
Last winter was expected to be active. It started as a weak La Nina, which would have meant a cold and snowy winter. But it then transitioned back into an El Nino pattern, giving us a warm end to the winter. In fact, Duluth’s 14th warmest in history!
We had above normal precipitation and only average snowfall which means most moisture that fell from the sky was in the form of rain. Although…
“Even last year when we were under a strong El Nino pattern we still had a typical arctic outbreak where temperatures were well below zero even minus 30s below zero in some areas.”
Are you ready for a colder and snowier winter? Because we are in a good position for a La Nina setup. Let’s look at a few projections.
A strong and dipping jet stream has already lead to some cold and snowy conditions. Parts because influences from high and low pressure aloft help steer the jet stream. One steering current is the north Atlantic Oscillation.
When high and low pressure above remain strong, cold air stays pooled by the arctic. But when high and low pressure weaken, it causes the jet stream to wobble and dip allowing clipper systems to dump snow on the northland.
The Pacific Ocean can influence our weather as well! When warm air surges towards Alaska it pushes cold air down into our area…. Resulting in an arctic outbreak…. Which we have already felt twice this week!
However, a cold start to winter doesn’t mean it’ll stay that way all season.
“You can’t really say what’s going on now is going to be showing us what’s going to be happening in the future”
Not all winters are equal, even on Great Lakes. Some years the lake freezes over, while others it remains open.
“The amount of ice that forms in any given winter is a really strong function of the average winter air temperature – average over the season.”
What’s interesting, it doesn’t take much – just a degree or two – to have an incredible impact on how much ice we actually get.
“These relatively small changes in winter conditions can have big impacts culturally, recreationally, and commercially even. It impacts our economy.”
The last time the lake almost completely froze over was in 2013–14. Since then, we’ve seen milder winters with less lake ice.
“Prior to about 1998 or so we typically had significant coverage on the lake. And that coverage has become much much less frequent during the 21st century.”
With less ice on the lake chances for accumulations really ramp up. So what does this mean for lake effect snow in the Northland? Here’s how the lake effect machine works. You have large Lake Superior with open water. The water stays warmer than land, because it takes more energy and time to change water temperatures than air temperatures.
So we see warmer air over Lake Superior. And colder air over the land. When our weather systems rapidly push the cold air from land across the open expansive warm water, we get warm air and moisture rising from the lake and forming clouds.
You need a 23 degree temperature difference between the two for this to happen. These clouds then continue downwind and crash into land, dropping significant lake effect snowfall.
“If you’re in Houghton, or out on the U.P. – the reason they have 8, 10, 12, feet of snow a year is because they’re downstream of a big chunk of Lake Superior.”
And the terrain enhances this.
The Sawtooth and Porcupine Mountains play a major role along the north shore and snow belt. Creating a pile up…. Essentially a traffic jam of clouds as they come across the lake and come to a halt as they slam into and lift up the mountains.
We had an unofficial start to winter two weeks ago. We are predicting December through February will have near average temperatures. We will go through the usual warm ups and extreme cold snaps, but our overall winter temps won’t be as warm as we felt the last two years.
As for snow, a weak La Nina gives us above average snow accumulations, and this year should be no exception. We are predicting around 65 inches of total snowfall over the next three months.
As for lake effect snow accumulations over the next three months, the Snow Belt will likely see near 180 inches, which is over 15 feet of total snow. The South Shore can expect a little less, near 110 inches, just shy of 10 feet. And the north shore around 75 inches near 6 feet.
So remember to be prepared for winter storms. Be able to stay off the grid for three days and have all the essentials ready right now in your house and your car.