Has Lake Michigan ever completely frozen over?

Dear Tom,
Has Lake Michigan ever completely frozen over?

–Hannah Senne
Dear Hannah,
Ice development on Lake Michigan usually begins in January and it attains its maximum extent in late February or early March, so this is the time of year for such an event to occur. However, constant wind and wave action combined with the vast reservoir of heat contained in the lake prevents it from freezing completely, even in the harshest winters.
According to Environment Canada and the U.S. National Weather Service, lake ice coverage has reached 90 to 95 percent in the coldest winters, including 1903-04, 1976-77 and 1978-79. Though travel across the lake on ice is impossible, in very cold winters ice will form and bank up solidly along shore areas, making it possible to travel around the lake entirely on ice. This happened in February 1899 and was noted in a 1959 article in the Chicago Tribune.

Saturday should be the warmest day so far this month….

Temperatures Saturday afternoon should rise above 40 degrees here in Chicago.  Many areas along the lake and even the Loop should make it out of the 30s today.   Follow the warmup with the current temps on the WGN Severe Weather Blog.

I’ve also posted a revealing graphic of what the 1960 (9.5 magnitude) Chilean Earthquake would look like on NOAA’s Tsunami forecast model.   

http://weblogs.wgntv.com/chicago-weather/severe-weather/

Deadly 1960 Tsunami compared to February 27, 2010

Tsunami predictions from computer models are still in the infancy stage, but the energy propagation forecast from NOAA’s MOST model performed quite well last week. 

Below are two projections off the MOST model.  The first, is the Tsunami energy projection from the 8.8 magnitude 2010 Chilean Earthquake.  The second, is what the model projection would have been from the 9.5 magnitude 1960 Chilean Earthquake.  It is clear that there was considerably more energy, and a much more dangerous Tsunami associated with the 1960 quake.    In 1960 Tsunami killed 61 people in Hawaii, and 138 in Japan.   

Below:  Maximum computed tsunami amplitude from 2010 Chilean Earthquake

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Below:  Maximum computed tsunami amplitude from the 1960 Chilean Earthquake

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The MOST (Method of Splitting Tsunami) model, is a series of numerical simulation codes capable of simulating three processes of tsunami evolution:

1) earthquake

2) transoceanic propagation

3) inundation of dry land

 

The main objective of this model is to provide an estimate of

1) wave arrival time

2) wave height

3) inundation area immediately after a tsunami event

Tsunami forecast models are run in real time while a tsunami is propagating in the open ocean, consequently they are designed to perform under very stringent time limitations.

 

Map/data courtesy of the NOAA Center for Tsunami Research/PMEL

 

50-degree mark proving elusive in the city

Chicago’s official thermometer at O’Hare International Airport peaked at 55 degrees on Dec. 1 and Chicagoans have not experienced 50-degree warmth since then. It was hoped that readings might hit 50 degrees this weekend, and that is still not out of the question in far south portions of metropolitan Chicago, from about Kankakee southward. For most of the area, however, 50 degrees this weekend is proving to be elusive. The combination of increasing afternoon cloudiness and the likelihood of cooling winds off Lake Michigan, whose water temperature is 34 degrees, will cap Saturday and Sunday readings in the 40s.

Looking to next week, a cloudy, cold and generally rainy weather picture emerges. Computer models indicate the development of a complex, sprawling area of low pressure over the mid-Mississippi Valley, and it is set to impact Chicago’s weather negatively.

– By Richard Koeneman, WGN-TV Meteorologist

Status of the recent U.S. drought

Dear Tom,
Droughts were in the news a couple years ago. What is the status now?

– Carlos Mendez

Dear Carlos,
Much of the United States experienced a withering drought in 2007 and 2008, and in portions of the Southwest, West and Southeast the drought began in 2005. At its worst in August 2007, 60 percent of the nation was in drought. In the Southeast, it was the worst drought in more than a century. Now, though, that figure has declined to 7 percent, according to the federal Climate Prediction Center. Douglas LeComte, a meteorologist with the center, says, “The lack of drought (now) is extraordinary.” There have been fewer than a half dozen times since the late 1800s when drought has been as sparse as it is now. Even California, which experiences chronic water shortages, is no longer in drought.