Friday looking like “Snowday” in Green Bay

Screen shot 2013-02-18 at 4.23.59 AMBut enough with the rhyming, right? Almost reminds you of that scene in “Happy Gilmore” when Christopher McDonalds character warns Adam Sandler to “Just stay out of my way… or you’ll pay! LISTEN to what I say!”

Any.. way.

The end of the week in Green Bay is looking whiter and whiter. A closed Low in the Rockies is looking like it will track northeastward toward the Great Lakes Wednesday and into Thursday night. This will set up a strong southerly flow and a surge of warmer moisture northward toward Wisconsin. At the same time surface winds will veer to the southeast and eventually the east. This could enhance any snowbands that do form.

Right now, I don’t think 2″ – 4″ of snow is out of the question for Green Bay, but heavier amounts could be possible based on some computer weather model guidance.

Here’s the breakdown!

As the aforementioned closed low moves northeastward the atmosphere aloft will diverge in front of it. Because physics says that “for every action there is an equal and oposite reaction” a void left in the atmosphere in one place means air from another place needs to move in to fill that void.

In the picture above, notice the isobars (the white lines) are spreading apart. That shows divergence in the upper atmosphere. In this case, as the atmosphere aloft at 300mb (or about 30,000ft) diverges it allows the air from below it to rise and fill it’s place. As that air rises, it cools and condenses and eventually precipitates.

To the left, here we are Friday morning. The flow aloft, as seen by the arrows, is from the south and southwest with plenty of divergence.

As it looks right now, surface winds will also be a factor.

Often times, Green Bay doesn’t get an opportunity for “Lake-Enhanced” snowfall, but Thursday and into Friday we could se this type of snow develop. It isn;t going to be true-blue lake effect snow, but weather models are suggesting a chance for  some enhancement of snowfall in certain areas dur to surface winds blowing from east to west.

Take a look!

To the right is a look at what the surface winds will be doing Thursday night.

Models are suggesting winds from the east at 10 to 20mph. This could helps to set up heavier snowfall right along Lake Michigan with some heavier snow bands further westward.

Alright, well based on all of this I’m still thinking between 2″ and 4″ are likely with a few areas receiving up to 6″ of snow. But, one weather model is suggesting upward of 6″ to 10″ of snow with a chance for up to 12″ in a few spots.

The GFS computer weather model shows lighter amounts as you move south of Green Bay toward Milwaukee and Chicago. The heaviest snowfall, it suggests will be north of town. But it pegs Green Bay with between  5″ and 7″ of snow!

Like I said, though, I still think this is a 2″ to 4″ event. But I’ll be watching it closely as we move through the week and into Thursday and Friday. Feel free to check back for updates!



Author of the article:


Nick Lilja

Nick is former television meteorologist with stints in Amarillo and Hattiesburg. During his time in Hattiesburg, he was also an adjunct professor at the University of Southern Mississippi. He is a graduate of both Oregon State and Syracuse University that now calls Houston home. Now that he is retired from TV, he maintains this blog in his spare time.