We’re big fans of the Chicago office of the National Weather Service – they might even say we stalk them from the amount of calls we throw at them weekly, if not daily.
So it was pretty cool to see them post up this gem of time-lapse reporting from the height of the Polar Vortex II on Tuesday. In addition to all the other stuff they monitor that you’d expect – radar, forecast, temperature, etc. – they also keep track of Lake Michigan conditions, including ice movement.
The radar image above shows the shelf of ice off the Chicago shore as it blows east in the teeth of Tuesday’s westerly winds. Here’s what you’re seeing, according to the NWS folks:
In the early images with a lower sun angle, it is a little hard to see the ice starting to move away from the Illinois and Wisconsin shore. In later images the growing gap between the ice and the shoreline becomes more apparent. East of the ice-covered area and into lower Michigan, clouds are forming as bitter cold air moves west to east over the relatively warm water.
Here’s another quick time-lapse showing the ice moving from 9 a.m. to 2:30 p.m. from the Harrison Crib, a meteorological monitoring station a few miles offshore.
The have a bit more information and data in their post comparing the snow and ice pack from Polar Vortex I two weeks earlier – pictured below in case you’ve blocked it from memory. As bad as that image looks, the ice buildup over that two week span is pretty dramatic according to the data they’ve recorded from the National Ice Center – yes, a real thing.
So what does all that mess look like from space? Glad you asked. This NOAA image, via Interlochen Public Radio in Michigan, shows a lot of ice pack on Lake Michigan.
Compared to this image from earlier in January. Not a lot of thawing going on there.
According to NOAA, that puts Lake Michigan at about 45 percent covered by ice, a progression shown in this chart from the GreatLakes Coast Watch:
In case you’re wondering, Lake Michigan isn’t close to the iciest of the Great Lakes. Lake Erie, the shallowest, is the most iced over with about 95 percent of the surface covered. The rest, in order:
- Lake Superior is about 85 percent ice-covered
- Lake Huron is at about 70 percent
- Lake Ontario is only about 25 percent
But that doesn’t make it any worse than any other winter, according to NPR.
“George Leshkevich is a researcher at NOAA’s Great Lakes Environmental Research Laboratory. He says you have to go back about 25 years to find this amount of ice in the Great Lakes this early but he says it is not unusual.
In comparison to the last few years this is quite a bit more,’ he says. ‘In comparison to winters in the 70s and 80s, this is not that anomalous.’ “