Yes, I can hardly contain my excitement. And by excitement I mean dread.
Having dug out of a foot of snow earlier this week and then watching with amusement/bemusement as Cleveland – only 35 miles to the north – froze over with 10 inches of snow and five-hour commutes from downtown, we now face the prospect of another winter dump. And it’s only Dec. 10! The crayon drawing (left) illustrates the powerful jet stream bringing an arctic blast deep into the South this weekend.
I know what you’re thinking. Gee, what’s all this talk about global warming if it’s snowing an unseasonably high amount this early in the winter?
Curiously, the “lake-effect” snow is caused by warm water. Meteorologists tell us that when an arctic wind blows over open (and relatively warm) water, it picks up that moisture and if the air is cold enough deposits it further downwind in the form of snow, sometimes in prolific amounts.
When the lake freezes over, the lake-effect engine shuts down.
Accuweather reported last February (2010) that Lake Erie had frozen over for the first time in 14 years. That’s a long time to go without freezing over. The Plain Dealer reported in in 2007 that Lake Erie has been on a 30-year warming trend.
We had a warmer-than-normal September and October this year, so the water temperature is probably above normal for this time of year as well (NOAA reports water temp off Cleveland is 38 degrees).
The National Oceanic and Atmospheric Administration (NOAA) produced a report in 2009, which stated: “More than 300 scientists from 160 research groups in 48 countries contributed to the report, which confirms that the past decade was the warmest on record and that the Earth has been growing warmer over the last 50 years.” I’ve not found NOAA to be a panic-prone “sky is falling” kind of outfit. Pretty much sticks to the facts. Small-craft advisories, tornado warnings, etc. So when they say the climate is on a warming trend, they’re probably right.
This doesn’t mean it doesn’t get cold, or that you won’t have snow storms, blizzards and deep freezes. There will be droughts, wet spells, hurricanes and tornadoes. Those things all still happen. In fact, volatile weather may trigger more extremes. But the average temps over time are trending higher.
Funny thing about lake effect snow is the longer the lake stays unfrozen, the more water evaporates from the surface. Lake Erie is a relatively shallow lake spread over quite a bit of square mileage. Freezing helps prevent (or at least slow down) evaporation. But those arctic winds act like a blow dryer (set on cool) on an unfrozen surface, slurping moisture off the surface and carrying it away. Which also has climatologists, ecologists, geologists and hydrologists and just about any other gists you can think of worried. Let’s save that doomsday scenario for another day.