Pretty “Cool” Ice Photos & Its “Effect” On Lake-Effect Snow

Think this winter’s been bad in the South?  Well imagine over 100 inches of snow… every year!  Places like the Great Lakes see it, routinely. You know when you hear about those Christmas or New Year’s reports of 35 inches of snow snarling holiday travel in places like Buffalo, New York?  Well, typically that’s caused by a phenomenon known as lake-effect snow.  Lake-effect snow is caused by an unstable atmosphere (similar to the atmosphere during a thunderstorm.)  In the case of thunderstorms, you have an atmosphere with lots of humidity, warm ground, and a cool upper atmosphere.  Lake-effect snow is caused by cold, arctic air rushing in on cold winds out of the northwest over the relatively warmer (and of course, moist) Great Lakes waters.  Now, of course, you need “water” to get lake-effect snow going.  If there’s ice covering the lake, the water vapor needed for lake-effect snow is not available and the lake basically “shuts down” for the production of lake-effect snow.

The Great Lakes, as you may  know, are very big: hundreds of miles long, tens of miles wide, and hundreds of feet deep, so it’s not likely they’ll all entirely freeze over for any significant amount of time, although it is, on rare occasion, possible that they’ll mostly freeze over, like during the very cold winters of 1976-1977, 1977-1978, and 1978-1979.  Most years, though, most locales on the lakes don’t get a break and get inundated with lake snow all winter long.

In several areas, though: far western New York, northwestern Pennsylvania, and northern Ohio, folks do get a break!  During the coldest months of the winter; it’s typical during many winters, the shallowest of all the lakes, Lake Erie, will nearly entirely freeze over and this nearly closes down the heavy snow machine along its shoreline.

February 8, 2011 Lake Erie Ice Cover, Image: NOAA

In the latest February image of Lake Erie taken via satellite above, you can see  there’s lots of white over the lake.  That’s actually a sheet of ice.  The darker black area, in fact, is the area of the lake that has been left uncovered and unfrozen. By far, there’s more ice than water.   Therefore, it’s tough to get much more than lake-effect flurries going.  Earlier in the season, though, before it really gets cold, it’s a totally different story.

January 11, 2011 Lake Erie Ice Cover, Image: NOAA

In the satellite photo above, you can see just a month ago, before the long duration of cold… the lake is wide open with plenty of water and water vapor to work with!  This is the season where we see the blizzards along the lake shore.

To check out the forecast in places affected by the lake  freeze-over lull, take a look at Cleveland and Buffalo.

On a side note, take a look at the imagery again and focus on the upper right.  That’s Lake Ontario.  It’s over 10 times deeper than Lake Erie.  You can see, between both photos, there’s not much change in the amount of white on the lake.  Lake Ontario, since its much deeper and contains a larger volume of water, has a much harder time cooling off and, therefore, has a much harder time freezing.  In places like Rochester and Watertown, New York, there’s nary a respite from the lake snow onslaught.

Great Lakes Snow Event

Lake Effect Snow Event, Image: NOAA

The National Weather Service is predicting heavy snow from Upstate New York to Ohio as a cold artic airmass continues to descend across the country.

See my previous post on lake effect snow.

A quiet weather pattern will remain in place across portions of the Central Plains and Mid-Atlantic region until Saturday.

Expect heavy rain along the Gulf Coast this Friday into Saturday.

Along the West Coast, another storm system will be a rain event for the Bay Area and Los Angeles, a snow event for the Sierra.

-Dawn Brown

Artic Air Follows Storm…